IMD 1.17: 11/11/2014 10:52:07 82VKXSVRDOS B* VERSADOS/RMS68K SRC/OBJ 4.4 (NOT BOOTABLE) SN=49367 6 OF 30 SR06q82VKXSVRDOS 0420¥o-*ˆThesevariablesareXREFedinthelinkchainfileM320DRV.LG=*ˆandallowtheusertomodifycertainmedia/driveparameters>*ˆwithouthavingtore-assemblethedriver.‚Seethelinkchain+*ˆfileforadescriptionoftheparameters.* ‰XREFFRMT_SD ‰XREFFRMT_DD ‰XREFFRMT_HD ‰XREFSETTM_5 ‰XREFSETTM_8‰XREFSETTM_HD‰XREFLDTM_5‰XREFLDTM_8 ‰XREFLDTM_HD **‰MISCEQUATES*5DRIVESƒEQU‡4“Maximumnumberofdrives(LUN)perboardEXEC…EQU‡0“RMS68Ktrap# PAGE**ˆMACROSUSEDBYTHISDRIVER* (* Macro file to use with VMEbus drivers:*ˆINCLUDE9995.&.DUALPORT.MC‰INCLUDE9995.&.DUALPORT.MC *ˆLONGWORDMACROK* This macro skips zero or more bytes in memory (if necessary) to align theM*assembler'slocationcountertoalong-wordboundary.‚Wedefinealong-wordC* boundary to be a location whose address is evenly divisible by 4.F* If the location counter isn't on a long-word boundary, advance it by-* one word to put it on a long-word boundary. LONGWORD MACRO‰DS.W…0 ‰IFNE…*/4*4-*‰DS.W…1‰ENDC‰ENDM *ˆMOVEIAMACROJ*‚Thismacroisusefulwhenwewanttoputanimmediatevalueintoan1*register,i.e.‚[]MOVEIAƒ,AnF* If the immediate value is less than or equal to $7FFF and it is alsoK* greater than or equal to -$8000, it fits within a 16-bit word as a signedJ*value.‚Inthiscase,weuseatwo-wordMOVE.Winstruction.Otherwise,we+* must use a three-word MOVE.L instruction. MOVEIAƒMACRO‰IFLE…\1-$7FFF‰IFGE…\1+$8000‰MOVE.Wƒ#\1,\2‰MEXIT‰ENDC‰ENDC‰MOVE.Lƒ#\1,\2‰ENDM PAGE *ˆMOVEQBƒMACROJ*‚ThismacroisusefulwhenwewanttoemployaMOVEQinstructiontoputaG* value into the rightmost byte of a Dn register and we don't care what5* value goes into the other bytes of the Dn register."*[]MOVEQBƒ,DnH*‚Iftheimmediatevalueisgreaterthan$7FanditisalsolessthanorI(U068>@;H>P8X6`<h2p:x9€:ˆ1:˜; 9¨7°-¸-À1ÈÐ7ØBà>è:ð;ø9<D I* equal to $FF, provide sign extension at the source level to prevent theH* assembler from giving a warning message that we don't want. Otherwise,I*usetheimmediatevalueasitis.‚IftheimmediatevalueisoutsidetheJ* range that can fit into a single byte, we'll get an error to alert us to* the problem. MOVEQBƒMACRO‰IFGT…\1-$7F‰IFLE…\1-$FF‰MOVEQ„#\1+$FFFFFF00,\2‰MEXIT‰ENDC‰ENDC ‰MOVEQ„#\1,\2‰ENDM *ˆMOVEQWƒMACROF*‚ThismacroisusefulwhenwewanttoputanimmediatevalueintotheL* rightmost word of a Dn register and we don't care what value goes into the * other word of the Dn register."*[]MOVEQWƒ,DnL*‚Iftheimmediatevalueislessthanorequalto$7FanditisalsogreaterK*thanorequalto-$80,itfitswithinasinglebyteasasignedvalue.‚InI*thiscaseweuseaone-wordMOVEQinstruction.‚Otherwise,wemustusea* two-word MOVE.W instruction. MOVEQWƒMACRO‰IFLE…\1-$7F‰IFGE…\1+$80 ‰MOVEQ„#\1,\2‰MEXIT‰ENDC‰ENDC‰MOVE.Wƒ#\1,\2‰ENDM #*‰Includethestandardequatefiles *‰INCLUDE‚STR.EQ*‰INCLUDE‚TCB.EQ*‰INCLUDE‚CCB.EQ*‰INCLUDE‚LV5.EQ*‰INCLUDE‚IOE.EQ*‰INCLUDE‚NIO.EQ PAGEŠNOLISTŠTTL†STR.EQŠINCLUDE‚9995.&.STR.EQŠNOLISTŠTTL†TCB.EQŠINCLUDE‚9995.&.TCB.EQŠNOLISTŠTTL†CCB.EQŠINCLUDE‚9995.&.CCB.EQŠNOLISTŠTTL†LV5.EQŠINCLUDE‚9995.&.LV5.EQŠLISTŠTTL†IOE.EQŠINCLUDE‚9995.&.IOE.EQŠNOLISTŠTTL†NIO.EQŠINCLUDE‚9995.&.NIO.EQŠTTL†VME320DRIVEREQUATESŠLIST PAGE*#*ˆPARAMETERSMASKFORVME320DRIVER* &*¨Noticethatsomeofthedefinedbits(*¦intheparametersmaskarenotusedby(*¦theVME320driver,butallofthebits)*¦thataredefinedforanydiskdriveare*¦showninthediagrams. **ƒ15‚14‚13‚12ƒ11‚10ƒ9ƒ8$*‚+---+---+---+---++---+---+---+---+*‚|‹|ƒ||ƒ|ƒ|ƒ|ƒ|$*‚+---+---+---+---++---+---+---+---+*„^ƒ^ƒ^ƒ^„^ƒ^ƒ^ƒ^*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ|/*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ----1=IOSSOFissignificant.*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|1*„|ƒ|ƒ|ƒ|„|ƒ|ƒ--------1=IOSPSMissignificant. *„|ƒ|ƒ|ƒ|„|ƒ|>*„|ƒ|ƒ|ƒ|„|ƒ------------1=IOSSHDisnotusedbytheVME320.*„|ƒ|ƒ|ƒ|„|A*„|ƒ|ƒ|ƒ|„----------------1=IOSTRKDisnotusedbytheVME320. *„|ƒ|ƒ|ƒ|9*„|ƒ|ƒ|ƒ---------------------1=IOSPCOMissignificant.*„|ƒ|ƒ|F*„|ƒ|ƒ-------------------------1=IOSSPTDisnotusedbytheVME320.*„|ƒ|<*„|ƒ-----------------------------1=IOSSRBissignificant.*„|K*„---------------------------------1=IOSRWCCBisnotusedbytheVME320. PAGE *„7ƒ6ƒ5ƒ4„3ƒ2ƒ1ƒ0$*‚+---+---+---+---++---+---+---+---+*‚|ƒ|ƒ|ƒ|ƒ||ƒ|ƒ|ƒ|ƒ|$*‚+---+---+---+---++---+---+---+---+*„^ƒ^ƒ^ƒ^„^ƒ^ƒ^ƒ^*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ|/*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ----1=IOSRECissignificant.*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|1*„|ƒ|ƒ|ƒ|„|ƒ|ƒ--------1=IOSRSZissignificant. *„|ƒ|ƒ|ƒ|„|ƒ|>*„|ƒ|ƒ|ƒ|„|ƒ------------1=IOSWTOisnotusedbytheVME320.*„|ƒ|ƒ|ƒ|„|@*„|ƒ|ƒ|ƒ|„----------------1=IOSRTOisnotusedbytheVME320. *„|ƒ|ƒ|ƒ|8*„|ƒ|ƒ|ƒ---------------------1=IOSSPTissignificant.*„|ƒ|ƒ|:*„|ƒ|ƒ-------------------------1=IOSHDSissignificant.*„|ƒ|<*„|ƒ-----------------------------1=IOSTRKissignificant.*„|>*„---------------------------------1=IOSILVissignificant. 6EQ010„EQU†1<EQ018„EQU†1<*„|ƒ|ƒ|ƒ---------------------1=Rigiddisk;0=floppydisk.*„|ƒ|ƒ|G*„|ƒ|ƒ-------------------------1=Doubledata-density(MFM)ondrive.*„|ƒ|¡(notused)D*„|ƒ-----------------------------1=Doubletrack-densityondrive.*„|¥(notused)C*„---------------------------------1=SeekrequiredonSMDdrive.PAGE¦(notused) IOPDMNTBEQU†12“DISMOUNTBIT 6EQ020„EQU†1<*‚$4ƒ|‚MaximumNumberofRetries‚|‚ActualNumberofRetriesƒ|?*ˆ+-----------------------------+-----------------------------+$*‚$6ƒ|‰DMATypeŒ|‡CommandOptions‡|?*ˆ+-----------------------------+-----------------------------+%*‚$8ƒ|“BufferAddress(upperword)|?*ˆ+-----------------------------+-----------------------------+%*‚$Aƒ|“BufferAddress(lowerword)|?*ˆ+-----------------------------+-----------------------------+!*‚$Cƒ|“BufferLengthRequested‘|?*ˆ+-----------------------------+-----------------------------+,*‚$Eƒ|ŽActualNumberofBytesTransferred‹|?*ˆ+-----------------------------+-----------------------------+*‚$10ƒ|–CylinderNumber–|?*ˆ+-----------------------------+-----------------------------+0*‚$12ƒ|„HeadorSurfaceNumberƒ|‡SectorNumber‰|?*ˆ+-----------------------------+-----------------------------+#*‚$14ƒ|‘CurrentCylinderPosition‘|?*ˆ+-----------------------------+-----------------------------+*‚$16ƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+ *‚$18ƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+*‚$1Aƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+*‚$1Cƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+*‚$1Eƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+'*‚$20ƒ|‡N0-Reserved‰|ˆN1-Reservedˆ|?*ˆ+-----------------------------+-----------------------------+'*‚$22ƒ|‡N2-Reserved‰|ˆN3-Reservedˆ|?*ˆ+-----------------------------+-----------------------------+,*‚$24ƒ|†N4-Post-DataGap…|ˆN5-Reservedˆ|?*ˆ+-----------------------------+-----------------------------+(*‚$26ƒ|†SectorLengthCode…|‹FillByte‰|?*ˆ+-----------------------------+-----------------------------+ PAGE **œECAFORMAT(continued)**‰Bit15°Bit0?*ˆ+-----------------------------+-----------------------------+*‚$28ƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+*‚$2Aƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+*‚$2Cƒ|™Reservedš|?*ˆ+-----------------------------+-----------------------------+)*‚$2Eƒ|ŠDriveType‰|…NumberofSurfaces†|?*ˆ+-----------------------------+-----------------------------+1*‚$30ƒ|„NumberofSectors/Track‚|ˆSteppingRateˆ|?*ˆ+-----------------------------+-----------------------------+-*‚$32ƒ|†HeadSettlingTime…|‡HeadLoadTimeˆ|?*ˆ+-----------------------------+-----------------------------+-*‚$34ƒ|‰SeekType‹|ƒReservedforControllerƒ|?*ˆ+-----------------------------+-----------------------------+**‚$36ƒ|LowWriteCurrentBoundaryTrackŽ|?*ˆ+-----------------------------------------------------------+(*‚$38ƒ|ŽPrecompensationBoundaryTrack|?*ˆ+-----------------------------------------------------------+*‚$3Aƒ|—ECCRemainder—|?*ˆ+-----------------------------------------------------------+*‚$3Cƒ|—ECCRemainder—|?*ˆ+-----------------------------------------------------------+*‚$3Eƒ|—ECCRemainder—|?*ˆ+-----------------------------------------------------------+(*‚$40ƒ|ŽAppendECCRemainderfromDisk|?*ˆ+-----------------------------------------------------------+(*‚$42ƒ|ŽAppendECCRemainderfromDisk|?*ˆ+-----------------------------------------------------------+(*‚$44ƒ|ŽAppendECCRemainderfromDisk|?*ˆ+-----------------------------------------------------------+*‚$46ƒ|™Reservedš|?*ˆ+-----------------------------------------------------------+*‚$48ƒ|™Reservedš|?*ˆ+-----------------------------------------------------------+*‚$4Aƒ|”VME320WorkingArea”|?*ˆ+-----------------------------------------------------------+*‚$4Cƒ|”VME320WorkingArea”|?*ˆ+-----------------------------------------------------------+*‚$4Eƒ|”VME320WorkingArea”|?*ˆ+-----------------------------------------------------------+*‚$50ƒ|”VME320WorkingArea”|?*ˆ+-----------------------------------------------------------+*‚$52ƒ|”VME320WorkingArea”|?*ˆ+-----------------------------------------------------------+*‚$54ƒ|”VME320WorkingArea”|?*ˆ+-----------------------------------------------------------+%*‚$56ƒ|ReservedfortheController|?*ˆ+-----------------------------------------------------------+ PAGEG*ˆThefollowingsectiondefinesthevariablesthatarecontainedinthe*‚VME320EventControlArea: ‰OFFSET„04CMDCODE‚DS.B†1•TheCMDCODEfieldoftheECAcontains(*¦thecommandcodethattellstheVME320*¦whatoperationtoperform. 4MAINSTATDS.B†1•TheMAINSTATfieldoftheECAisset%*¦bytheVME320andcontainsthemain'*¦statusvalueaboutcommandexecution.)*¦ThevaluesforMAINSTATcanbefoundin'*¦theerrorcodetableinthisdriver's*¦interrupthandler. 2EXTSTAT‚DS.W†1•TheEXTSTATfieldoftheECAisset%*¦bytheVME320andcontainsthebit-)*¦orientedstatusaboutcommandexection. 6MAXRETRYDS.B†1•TheMAXRETRYfieldoftheECAcontains#*¦themaximumnumberofretriesPER (*¦COMMANDthattheVME320shouldattempt'*¦afteradiskoperationerror.‚Zeroin"*¦thisfieldindicatesnoretries. 0RETRY„EQU‡10’TherecommendedvalueforMAXRETRY.5MINTRYƒEQU‡1“Minimumretrycounttovalidatesectors.ééééééé 4ACTRETRYDS.B†1•TheACTRETRYfieldoftheECAisset'*¦bytheVME320andcontainstheactual)*¦numberofretriesexecutedPERCOMMAND. 4DMATYPE‚DS.B†1•TheDMATYPEfieldoftheECAcontains'*¦avaluerepresentingtheDMAtransfer(*¦modeofoperation-holdingthebusor*¦releasingthebus. PAGE3*ˆThesevariablesarepartoftheVME320ECABlock. +DMA†EQU‡0•ThisvalueenteredintheDMATYPE'*¦fieldallowstheusertofreethebus(*¦betweentwo-wordtransfers.‚Anon-zero(*¦valuewouldallowtheusertokeepthe*¦busforupto200usec. 2CMDOPTƒDS.B†1•TheCMDOPTfieldoftheECAcontains**¦optionsapplicabletoreadcommandswhen&*¦handlingdeleteddataaddressmarks. /OPT0…EQU‡0•ThisbitintheCMDOPTfielddefines&*¦thehandlingofdeleteddataaddress&*¦marks.A'0'inthisfieldskipsthe)*¦sectorwithadeleteddataaddressmark'*¦asifitdidnotexist.A'1'inthis%*¦fieldtransfersthesectorwiththe)*¦deleteddataaddressmarkregardlessof&*¦theCRC/ECCcheckandterminatesthe*¦operation. /OPT2…EQU‡2•ThisbitintheCMDOPTfieldenables&*¦automaticerrorcorrection.A'1'in)*¦thisfieldusestheECAremainderfield)*¦intheECAandcorrectsthedatainthe#*¦VME320internalmemory.Theerror)*¦correctionvectorandrelativeposition$*¦aresavedintheECAworkingarea. >OPT†EQU‡0<FORMSIZEEQU‡EQ070/PAGESIZE†memoryforawritebufferrequired$*¦forformattracksontheVME320.4 *¦bytespersectorpertrackare'*¦requiredforfloppiesand5bytesfor *¦harddisks. PAGEF*ˆThevariablesthataredefinedbelowbegintheI/Ocompletionevent. '‰OFFSETƒ0–ThisOFFSETblockdefinesthe'*¦structureofanI/Oevent.‚Weuseone)*¦variationoftheeventstructureforan"*¦I/Ocompletionevent,andweuse *¦anothervariationoftheevent%*¦structureforanunsoliciteddevice*¦event. 1EVNTLEN‚DS.B…1–Thisfieldspecifiesthelengthof'*¦theevent.‚Thelengthisspecifiedin%*¦termsofthenumberofbytesinthe*¦event. 3EVNTCODEDS.B…1–Thisfieldcontainstheeventcode,4EVNTIOƒEQU†$01’whichspecifiestheclassificationofSERVECT‚DC.L…INTERUPT-SERVECT‡Thisentryintheservicevector(*¦tablecontainstherelativeaddressof(*¦theVME320driver'sinterrupthandler.(*¦Theinterrupthandlerreceivescontrol&*¦fromCMRwhenCMRwishestopollthe$*¦VME320drivertoseeifthedriver(*¦wantstohandlethecurrentinterrupt.'*¦PleasenoticethatthelabelINTERUPT&*¦isintentionallymisspelledtolimit*¦thelengthofthelabel. 7‰DC.L…COMMANDS-SERVECT‡Thisentryintheservicevector(*¦tablecontainstherelativeaddressof(*¦theVME320driver'scommandprocessor.&*¦CMRcallsthecommandprocessorwhen&*¦CMRhasacommandtoinitiateanI/O"*¦transactiononaVME320channel. 6‰DC.L…INITIAL-SERVECTˆThisentryintheservicevector(*¦tablecontainstherelativeaddressof)*¦theVME320driver'sinitializationsub-'*¦routine.‚CMRcallstheinitialization'*¦subroutineatchannelallocationtime)*¦togivethedriverachancetoallocate(*¦memoryforvariablesand/ortodoany-'*¦thingthatisnecessarytoinitialize(*¦thechannelandthechanneldevice(s). 7‰DC.L…RESERVED-SERVECT‡Thisentryintheservicevector7RESERVEDEQU†SERVECTŽtableisnotused,butisreserved*¦forSYSFAIL. PAGE * CMR PARAMETER TABLE * 2‰DC.B…EXTCCBSZThisfieldtellsCMRhowmanyextra&*¦page(s),ifany,toallocateforthe%*¦CCBforthisI/Odriver.‚CMRalways(*¦allocatesonemorethanthisnumberof'*¦page(s)becauseonepageofmemoryis&*¦requiredfortheuniversally-defined'*¦CCBvariables.‚Theadditionalpage(s)&*¦thatarespecifiedbythisfieldare'*¦usedexclusivelyfordevice-dependent$*¦variablesthatarerequiredbythe*¦devicedriver. 0‰DC.B…0,0,0’Thesefieldsarereservedforfuture.‰DC.L…0,0,0extensions.‚Weprovidezerovalues%*¦herebecauseanyextensionsthatwe(*¦implementinthefuturewillinterpret%*¦zeroasaninnocuousdefaultvalue. * REVISION TABLE * 0‰DC.B…'02'MM„Thisportionoftherevisiontable3‰DC.B…'25'DD‚containsthedateonwhichthedriver3‰DC.B…'85'YY‚wasassembledforarelease.‚Thedata)*¦isgivenasMMDDYYwithtwodigitseach'*¦forthemonth,theday,andtheyear. .‰DC.B…''”ThisbytecontainsanASCIIblankto%*¦indicatethatthedriver's.LOfile*¦doesn'tcontainanypatches. .‰DC.B…'4'”ThisbytecontainsanASCIIdigitto&*¦indicatethemajorVERSAdosrevision(*¦numberunderwhichthisversionofthe*¦driverwasfirstreleased. PAGE‰TTL‡VME320INITIALIZER O*******************************************************************************O*********************************************************************************ˆINITIALIZATIONROUTINE*B*ˆThis‚subroutineiscalledfromCMR‚whenCMRisinvokedbyataskB*ˆ(normallyIOI)to‚allocateachannel.‚ItspurposeistogivetheD*ˆdriverachancetosetupthingsforcommandserviceandinterrupt-*ˆservice.‚Thebasicfunctionsperformedare:* *’Initializeinternalvariables.:*’AllocateglobalmemoryfortheEventControlAreas(ECA)!*’InitializeECAAddressPointer.**’InitializeECAdriveinterruptregister.3*’InitializeECAdrivesourceandstatusregisters.*B*ˆThissubroutineisenteredthroughaJSRfromCMR,andwillexit7*ˆwithanRTS.‚Theprocessorisinthesupervisormode.*%*ˆEntry:„A6=physicaladdressofTCB*’A5=physicaladdressofCCB*!*ˆRegisterusage:ˆ01234567 *œD‚****œA‚*‰P**ˆExitsto:CMRviaRTS*O*******************************************************************************O******************************************************************************* INITIAL: 7‰LEA†V320IDLE(PC),A0ˆInitial izetheinterrupthandler's@‰MOVE.LƒA0,INTSWTCH(A5)†co-routineswitchtopointtotheVME320'*¦IDLEroutinesowe'llbeprotectedin(*¦casetheVME320controllererroneously'*¦generatesaspuriousinterruptbefore%*¦we'veevergiventhecontrollerany"*¦commands.‚Thisstepisn'treally'*¦necessary,butitgivesussomeextra)*¦protectionagainstanerrorthatshould*¦neveroccur. 9‰LEA†CCBZERO(A5),A0‰Clearallofthedevice-dependentCCB=‰MOVEQWƒ(CCBZSIZE/4)-1,D0„variablesthatmustbebackgrounded(*¦withzerosatchannel-allocationtime.(*¦TheexecclearedalloftheCCBmemory'*¦beforethistime,sothisisactually*¦notnecessary. PAGE5INIT10ƒCLR.L„(A0)+’Wecleartwowordsatatimeuntil0‰DBRA…D0,INIT10Œwe'veclearedallofthedevice-&*¦dependentvariablesthatliebetween$*¦CCBZEROandtheendoftheCCB.‚We)*¦improveourexecutionspeedsomewhatby)*¦clearingtwowordsatatimeinsteadof&*¦clearingonewordatatime.‚Wetake)*¦stepselsewheretoensurethatCCBZSIZE(*¦isamultipleof4andthatCCBZEROis*¦onalong-wordboundary. 8‰MOVE.Lƒ#PAGES,A0ŽAllocateglobalmemoryforoneECAfor5‰MOVE.Lƒ#4,D0eachpossibledeviceandtheassociated*‰TRAP…#0“ECApointertable.‚Theaddressof'*¦thememorysegmentisreturnedinA0.*‰BRA.S„INIT30Goodreturn!‰BRA†INITERRŽBadreturn.INIT30:‰MOVE.LƒA0,ECATABLE(A5)ˆStoretheECAtableaddressinthe3‰MOVEQ.L‚#DRIVES,D1‹CCB.‚Clearallmemorylocations6‰MULU…#PKTLONG,D1ŠinallfourECApacketsplustheECA/‰ADDQ.Lƒ#4,D1tableitself,andrestoretheECA'INIT45ƒCLR.L„(A0)+tableaddresstoA0.‰DBRA…D1,INIT45‰MOVE.LƒECATABLE(A5),A0*@*ˆAdjusttheglobalramaddressoftheECApointertableandthe7*ˆECApacketsifanonboardram/offsetaddressapplies.* ‰GO_OFF_BDA0!*¨GetthebaseaddressoftheECA(‰MOVE.LƒA0,D0PointerTable.‚Immediately6‰ADD.L„#16,D0followingthetablearetheECApackets.;‰MOVEQ.L‚#DRIVES-1,D1‰FilltheECAtableinglobalramwith7‰MOVE.LƒECATABLE(A5),A0†theECApacketaddressesofthe>INIT40ƒMOVE.LƒD0,(A0)+fourpossibledrivesonthecontroller.‰ADD.L„#PKTLEN,D0‹*‰DBRA…D1,INIT40Œ* PAGE‰MOVE.LƒECATABLE(A5),A0*@*ˆAdjusttheglobalramaddressoftheECApointertableandthe7*ˆECApacketsifanonboardram/offsetaddressapplies.* ‰GO_OFF_BDA0#*©GettheECAPointerTableaddress1‰MOVE.LƒA0,D1intoaworkingregister.‚Wehaveto4‰ROR.L„#1,D1translatetheaddressbeforewetellit5‰MOVEQ.L‚#2,D2tothecontroller.Theaddressmustbe1‰MOVE.BƒD1,D0dividedby2andtheorderofbytes4INIT50ƒASL.L„#8,D0reversedi.e.theMSBbecomesthe.‰ASR.L„#8,D1LSBandtheLSBbecomestheMSB-5‰MOVE.BƒD1,D0(theaddressAABBCCDDbecomesDDCCBBAA)‰DBRA…D2,INIT50 9‰MOVE.LƒCCBCHB(A5),A0ŠGetthecontrolleraddressandtell9‰MOVEP.L‚D0,ECA0(A0)ŠtheECAPointerTableaddresstotheD‰MOVE.BƒCCBVECT(A5),VECTOR(A0)controllerthroughtheECAregisters.;‰MOVE.Bƒ#0,SOURCE(A0)ˆTellthecontrollerthevectornumber:‰MOVE.Bƒ#0,STATUS(A0)ˆandinitializethesourceandstatus‰BRA.S„INITDONEregisters. 4INITERR‚SNE.B„V320DOWN(A5)‹Ifanerrorwasdetected,1INITDONERTS›shutthechanneldownbysettingthe *¦variableV320DOWNtonon-zero.‰PAGE‰TTL‡VME320COMMANDHANDLER O*******************************************************************************O*********************************************************************************ˆCOMMANDSERVICEROUTINE*C*ˆThissubroutineiscalledfromCMRwhenCMRreceivesacommandtoA*ˆinitiatean‚I/Otransaction‚withadevicethatiscontrolledbyB*ˆthisdriver.‚ThepurposeistoperformthecommontasksthatareB*ˆnecessaryforallcommandroutines,andto‚directcontroltotheA*ˆindividualroutinethatprocessesthe‚givencommand‚throughthe*ˆcommandswitchingtable.*5*ˆEntry:„A2=PhysicaladdressofCMRparameterblock*’A5=PhysicaladdressofCCB/*’A6=Physicaladdressof TCBofattachedtask*"*ˆRegistersusage:„01234567 *™D‚***…RR*™A‚*RPRRPP*5*ˆExit:…A1=Pointertodrive'svariableblockinCCB*’A3=PhysicaladdressofDCB*’A4=PhysicaladdressofIOCB*’D5=0*’D6=Channeldevice#*9*ˆExitsto:Theroutinethatprocessesthegivencommand.*O*******************************************************************************O******************************************************************************* CMDSWIT: 3‰DC.W…READCMD-*-4ŒThereadcommandtellstheVME3201‰DC.W…IOREADdrivertoreaddatafromadiskinto *¦memory. 5‰DC.W…WRITECMD-*-4‹ThewritecommandtellstheVME3202‰DC.W…IOWRITdrivertowritedatafrommemorytoa*¦disk. 5‰DC.W…STATCMD-*-4ŒThestatuscommandtellstheVME3204‰DC.W…IOSTATdrivertoreturnthecurrentstatusand *¦configurationofadiskdrive. 7‰DC.W…CONFIG-*-4TheconfigurecommandtellstheVME3204‰DC.W…IOCNFGdrivertochangethecurrentconfigura-(*¦tionofadiskdriveandissuesaseek*¦commandtothatdrive. 3‰DC.W…DFCONFIG-*-4‹Thechangedefaultconfiguration/‰DC.W…IOCHDCcommandtellstheVME320driverto%*¦changethedefaultconfigurationof*¦adiskdrive. PAGE 4‰DC.W…FORMAT-*-4TheformatcommandtellstheVME3200‰DC.W…IOFRMTdrivertoformataparticulartrack*¦ofadisk. &‰DC.W…0–Thiszerosentinelwordinthe'*¦positionofanoffsetvaluemarksthe*¦endoftheswitchingtable. COMMANDS: 6‰MOVE.LƒSP,SAVESP(A5)ŠSavethestackpointersowecan$*¦laterabortatanylevelofnested$*¦subroutinesandeasilyrestorethe%*¦stackenvironmentthatexistedwhen*¦thisroutinebeganexecution. :‰MOVE.LƒXIOCPK(A2),D6ŠGetthephysicaladdressoftheIOCB2‰MOVEQ.L‚#0,D5forthecommandintoA4.‚Subroutine7‰MOVE.WƒXIOPLN(A2),D5ˆLOGPHY1convertsthelogicalIOCB4‰BSR†LOGPHY1Žaddress(inD6)intoaphysicaladdress-‰MOVE.LƒD6,A4forus.‚Wemustcallsubroutine)*¦LOGPHY1withA5containingthephysical(*¦addressoftheCCB,andwemustsetup(*¦D5tospecifythelength(inbytes)of%*¦theIOCB.‚TheCCBTASKAfieldofthe'*¦CCBmustcontainthephysicaladdress(*¦oftheTCBthatcontrolsthetaskthat#*¦ownstheIOCB.‚SubroutineLOGPHY1%*¦returnsthephysicaladdressofthe *¦IOCBinD6. &*¨SubroutineLOGPHY1abortsprocessing$*¦iftheIOCBthatwespecifyisnot'*¦entirelywithinamemorysegmentthat)*¦belongstothetaskthatownstheIOCB.&*¦Thiserrorcanneveroccurinactual%*¦practice,though,becauseahigher-)*¦levelroutinehasalreadyverifiedthat(*¦theIOCBliesentirelywithinamemory'*¦segmentthatbelongstothetaskthat*¦ownstheIOCB. PAGE 9‰MOVE.LƒXIOUID(A2),A3ŠGetthephysicaladdressoftheDCB2‰MOVEQ.L‚#0,D6intoA3,andgetthechanneldevice;‰MOVE.BƒDCBCDV(A3),D6ˆnumberintoD6.‚Thesevaluesindicate&*¦theparticulardevicethatshouldbe*¦accessedbythecommand. :‰MOVEQBƒISTACDN,D1ŒIftheVME320channelisdown,goqueue:‰TST.B„V320DOWN(A5)‰aneventtotheattachedtasktoindi-7‰BNE.S„CMDEXIT2catethatthechannelisoutofservice(*¦fornow.‚Wecan'tprocessanycommands)*¦foranyVME320deviceswhenthechannel(*¦isdownbecausethechannelbeingdown&*¦indicatesthattheVME320Peripheral*¦Adapterisnotfunctional. 5‰LEA†DRVBLK(A5),A1ŠSetupA1topointtothevariable:‰MOVEQWƒDRVBLKSZ,D0Šblockforthediskdrivethatistobe-‰MULU…D6,D0accessedbythecommand.‚Thedisk4‰ADD.L„D0,A1drive'svariableblockisinthedrive-(*¦associatedportionoftheCCB,andthe)*¦particularvariableblockinthedrive-)*¦associatedareaoftheCCBisindicated'*¦bythedrive'schanneldevicenumber.(*¦Thecodeheredependsonthefactthat)*¦thedrive-associatedportionoftheCCB%*¦isorganizedintoparallelvariable)*¦blockswithonevariableblockforeach*¦driveonthechannel. 7‰MOVE.WƒIOSFCT(A4),D0ŠNowpreparetosearchthecommand;‰LEA†CMDSWIT(PC) ,A0‡switchingtableforthecommandthatis6‰MOVEQBƒISTAIF,D1ŒspecifiedbytheIOSFCTfieldofthe$*¦IOCB.‚WeputtheIOSFCTvalueinto%*¦D0.W,andweputtheaddressofthe(*¦switchingtableintoA0.‚Wealsoputa$*¦statuscodeintoD1.B.‚Thisstatus'*¦codewillbeusedifthegivenIOSFCT%*¦valuedoesn'tcorrespondtoavalid*¦commandcode. PAGE 4CMD10„MOVE.Wƒ(A0)+,D2Thisloopsearchesthecommand7‰BEQ.S„CMDEXIT2switchingtabletoseeifwecanfinda6‰CMP.W„(A0)+,D0matchfortheIOSFCTvalueinD0.W.‚If4‰BNE.S„CMD10wereachtheend-of-tablesentinelword)*¦withoutfindingamatch,wegoqueuean&*¦eventtotelltheattachedtaskthat)*¦we'vereceivedaninvalidcommandcode.&*¦Otherwise,wesetupD2.Wtocontain&*¦theswitchingoffsetfortheroutine!*¦thathandlesthegivencommand. /‰MOVEQ.L‚#0,D5’ClearD5toprovideaconvenient$*¦initialvaluefortheroutinethat#*¦processesthegivencommand.‚Some)*¦command-processingroutinesmakeuseof*¦thisinitialvalueofD5. 4‰JMP†0(A0,D2.W)Transfercontroltotheroutinethat%*¦processesthegivencommand.‚Please&*¦refertothecommandswitchingtable(*¦andtothesearchingloopabovetosee'*¦howtheoffsetvaluehereisderived. PAGE O*********************************************************************************ˆSTATUSCOMMANDROUTINE*G*ˆThecommandserviceprocessorinvokestheSTATCMDroutineinresponseE*ˆtoastatuscommand.‚Itspurpose‚istosetuptheusertask'spara-F*ˆmeterblocktoreflectthe‚drive'scurrentstatusandconfiguration.*6*ˆEntry:„A1=Pointertodrive'svariableblockinCCB2*’A2=Pointertodrive'sECAblock(notrequired)*’A3=PhysicaladdressofDCB*’A4=PhysicaladdressofIOCB*’A5=PhysicaladdressofCCB/*’A6=PhysicaladdressofTCBofattachedtask**’D5=03*’D6=Channeldevice#forthediskdrive(DCBCDV)*!*ˆRegisterusage:…01234567 *™D‚*‰***™A‚*P*PPPP*7*ˆExit:…Fallsthroughtocommonexitroutine(CMDEXIT).*O******************************************************************************* STATCMD: :EQ100„EQU†CONFGBLK+IOSATWˆSetupA2topointtotheIOSATW5‰LEA†EQ100(A1),A2‰fieldoftheconfigureblockinthe%*¦drive'svariableareainthedrive-%*¦associatedportionoftheCCB.‚That&*¦configureblockcontainsthedrive's'*¦currentconfiguration,andthat'sthe)*¦configurationthatwewanttoreturnto*¦theusertask. 1‰BSR.S„STATCONFSubroutineSTATCONFsetsupA0to'*¦pointtotheIOSATMfieldoftheuser%*¦task'sstatusparameterblock.‚Sub-&*¦routineSTATCONFalsodeterminesthe$*¦drive'sdevicestatusandsetsthe#*¦firstgroupoffieldsintheuser *¦task'sstatusparameterblock. "*¨SubroutineSTATCONFdestroysthe'*¦valuesofregistersD6andD5,andit(*¦usestheinputvaluesofregistersA1,*¦A2,A4,A5,andA6. PAGE 7EQ110„EQU†IOATM<<16ŽSettheIOSATMfieldandtheIOSPRM:‰MOVE.Lƒ#EQ110+IOPRM,(A0)+ƒfieldintheusertask'sstatus%*¦parameterblock.‚Thevaluesthatwe(*¦returntotheusertaskforthesemask%*¦fieldscontainallofthemaskbits$*¦thataresignificanttotheVME320&*¦driver.‚NoticethatweadvanceA0to'*¦pointtotheIOSATWfieldoftheuser *¦task'sstatusparameterblock. 7EQ120„EQU†IOSDLN-IOSATWŠThecodebelowassumesthatthe6EQ130„EQU†EQ120/2Žconfigureblockcontainsanintegral8EQ140„EQU†EQ130*2Žnumberofwords(asitalwaysshould).9‰IFNE…EQ120-EQ140ŠIfthisassumptionisnottrue,wewant/‰FAIL…0”[****ERROR****ERROR****ERROR****],‰ENDCštogenerateanassemblyerrortoalert'*¦thecurrentmaintenanceprogrammerto&*¦theproblem.‚Theinstructionthatis$*¦normallyskippedheregeneratesan*¦assemblyerror. 7‰MOVEQWƒEQ130-1,D0Thisloopcopiesthedrive'scurrent)*¦configurationvaluesfromtheconfigure@STA10„MOVE.Wƒ(A2)+,(A0)+Šblockinthedrive'sareaofthedrive-3‰DBRA…D0,STA10assoc iatedportionoftheCCBtothe(*¦usertask'sstatusparameterblockone)*¦wordatatimeinsteadofonebyteata*¦timeforimprovedspeed. "*¨Controlfallsfromhereintothe!*¦commandprocessor'scommonexit *¦routine. PAGE O*********************************************************************************ˆCOMMONEXITROUTINE*B*ˆTheCMDEXIT‚routineisa‚commonexitroutinethatisusedbytheC*ˆmanydifferentpathsthroughthecommandserviceroutine.‚ControlC*ˆcomestooneofthreeentrypointsbelowtoterminateprocessing.*%*ˆEntry:„A3=PhysicaladdressofDCB*’A4=PhysicaladdressofIOCB*’A5=PhysicaladdressofCCB3*’A6=PhysicaladdressofTCBoftheattachedtask**D1.B=IOSSTAstatusvalue*!*ˆRegisterusage:…01234567*™D‚R**™AˆPPPP**ˆExit:…ReturntoCMRviaRTS*O******************************************************************************* CMDEXIT: ;CMDEXIT1MOVEQBƒISTAOK,D1ŽControlreachesthispointinthe'*¦commandprocessorwhenwe'vefinished)*¦processingacommandwithnoerrorsand$*¦wewanttoqueueanI/Ocompletion(*¦eventtonotifytheattachedtaskthat)*¦theprocessingforthecommandhasbeen&*¦completedwithnoerrors.‚Thestatus&*¦valuethatwepickuphereindicates$*¦thatnoerrorshavebeendetected. PAGE 6CMDEXIT2BSR†QEVENTTControlreachesthispointinthe'*¦commandprocessorwhenwe'vefinished%*¦processingacommandandwewantto)*¦queueanI/Ocompletioneventtonotify'*¦theattachedtaskthattheprocessing%*¦forthecommandhasbeencompleted.$*¦Thestatusvalueforthecompleted'*¦commandisinD1.Bwhencontrolcomes*¦here. #*¨Thisroutinecannotbeusedfora'*¦commandwhoseprocessingiscompleted(*¦underinterruptcontrolbecauseevents&*¦mustbequeueddirrerentlywhenthey'*¦arequeuedfromaninterrupthandler.(*¦Thisroutineisusedonlywhenwewant$*¦toqueueaneventfromthecommand'*¦serviceroutine,whichisnotinvoked*¦underinterruptcontrol. BCMDEXIT3MOVE.LƒSAVESP(A5),SPŠRestorethestackpointer,andclear4‰MOVEQ„#0,D0D0toindicatethatthecommandservice(‰RTS›routinehasoperatedproperly.‚Then$*¦returncontroltotheroutinethat$*¦calledsubroutineCOMMANDS.‚Notice(*¦thatwecanusethisreturnroutineto(*¦abortprocessingfromanylevelwithin(*¦thecommandserviceroutinebecausewe(*¦restorethestackpointertothevalue'*¦ithadwhensubroutineCOMMANDSbegan*¦executionatitsmainlevel. #*¨Ourhandlingofthestackpointer'*¦appearstoeliminatere-entrancy,but**¦theVME320driverisstillre-entrantin'*¦thenecessarycontextbecausesubrou-%*¦tineCOMMANDScanneverbecalleda)*¦secondtimeforthesameVME320channel(*¦untilwereturncontrolfromthefirst'*¦calltotheattachedtask.‚Subroutine)*¦COMMANDScanbecalledre-entrantlyfor%*¦anotherVME320channelbecauseeach$*¦channelhasitsownCCB.‚Also,the)*¦VME320interrupthandlercanbeinvoked%*¦whilesubroutineCOMMANDSisinthe*¦middleofitsexecution. PAGE O******************************************************************************** *ˆSTATUS/CONFIGURECOMMONCHORES*F*ˆThesubroutineSTATCONFperformsfunctionsthatarecommontostatus?*ˆcommands,configurecommands,anddefaultconfigurecommands.*6*ˆEntry:„A1=Pointertodrive'svariableblockinCCB<*’A2=IOSATWfieldindrive'sconfigureblockofCCBorDCB*’A4=PhysicaladdressofIOCB*’A5=PhysicaladdressofCCB*!*ˆRegisterusage:…01234567*™DŒ***™A‚*P…PP*&*ˆExit:…Returntothecallingroutine.*O******************************************************************************* STATCONF: ;‰MOVE.LƒIOSDBP(A4),D6ŠGetthephysicaladdressofthefirst9‰MOVE.Lƒ#IOSDLN,D5‹locationoftheusertask'sconfigure/4‰BSR†LOGPHY1ŽstatusparameterblockintobothD6and9STATCON1MOVE.LƒD6,A0A0.‚SubroutineLOGPHY1convertsthe'*¦logicaladdress(passed inD6)ofthe(*¦user'sparameterblockintoaphysical"*¦address.‚Wemustcallsubroutine)*¦LOGPHY1withA5containingthephysical(*¦addressoftheCCB,andwemustsetup(*¦D5tospecifythelength(inbytes)of'*¦theconfigure/statusparameterblock.$*¦TheCCBTASKAfieldoftheCCBmust)*¦containthephysicaladdressoftheTCB&*¦thatcontrolsthetaskthatownsthe#*¦configure/statusparameterblock.)*¦SubroutineLOGPHY1returnsthephysical'*¦addressoftheparameterblockinD6. &*¨SubroutineLOGPHY1abortsprocessing(*¦andreportsanerroriftheconfigure/(*¦statusparameterblockthatwespecify)*¦isnotentirelywithinamemorysegment)*¦thatbelongstothetaskthatallegedly'*¦ownstheparameterblock.ƒ(Continued) PAGE %*¨TheSTATCON1entrypointtosubrou-(*¦tineSTATCONFisaspecialentrypoint'*¦thatcanbeusedtosavetimewhenD6#*¦alreadypointstotheusertask's#*¦configure/statusparameterblock. 8‰TST.B„MOUNTED(A1)ŒIfthediskisnotcurrentlymounted,/‰SEQ.B„(A0)‘wesettheXDSNRBbitoftheIOSDST9‰AND.B„#1<EQ250„EQU†CONFGBLK+IOSRTO†block.‚Theuserisn'tallowedtosetC‰MOVE.LƒEQ24 0(A3),EQ250(A1)‚orchangethesevalueswithaconfigure'*¦command,sowealwaysusethedefault%*¦values.‚Weneedtoputthesevalues&*¦intothecurrentconfigurationblock$*¦nowsowe'llhavetherightvalues)*¦therewhenwecopythemintotheuser's'*¦configureparameterblock.‚Also,this%*¦codesetsthesefieldsproperlyfor*¦subsequentstatuscommands. PAGE 6EQ260„EQU†1<*‚willreflectthetotalconfigurationthatisbeingproposed. F*ˆRecallthatD1.W=0fromabove.‚Wealso haveD2.W=IOSPRMfromtheH*‚usertask'sconfigureparameter‚block,‚orelsewe‚have‚D2.W=$FFFF‚ifK*‚we'reprocessing‚thefirst‚configurecommandordefaultconfigurecommandI*‚thathas‚been‚processedforthis‚disksincesystem-initialization‚time.L*‚Additionally,wehave‚A0=LOC(IOSREC)intheusertask'sconfigureparam-I*‚eterblock,‚andwe‚have‚A2=LOC(IOSREC)‚intheconfigureblockthatis*‚beingupdated. 2‰BRA.S„CNF140‘Branchintotheloopthatmergesthe#*¦parametervalues.‚We'lluseD1.W,%*¦whichequalszerofromabove,asan$*¦indexintotheCONFGLENtable.‚The$*¦CONFGLENtablecontainsaone-byte'*¦entryforeachparametervalueinthe&*¦configureblock,andthevalueofan(*¦entryisN-1whereNisthelength(in'*¦bytes)ofthecorrespondingparameter'*¦field.‚Theendofthetableismarked*¦bya-1sentinelvalue. %*¨Wecouldeasilyrearrangesomecode%*¦toeliminatethebranchinstruction&*¦thatisusedhere,buttheresulting*¦codewouldlosesomeclarity. PAGE O*********************************************************************************ˆCONFIGURATION-LENGTHTABLE*F*ˆThis‚tabledefinesthelengthofeachparameterfieldinaconfigureF*ˆblockforadiskdrive.‚ThereisoneentryintheCONFGLENtableforE*ˆeach‚parameterfieldina‚configureblock,andthevalueofatableD*ˆentryis‚N-1whereNis‚thelength(inbytes)‚ofthecorresponding*ˆparameterfield.*O******************************************************************************* CONFGLEN: )‰DC.B…IOSRSZ-IOSREC-1†Length(IOSREC)-1.)‰DC.B…IOSWTO-IOSRSZ-1†Length(IOSRSZ)-1.)‰DC.B…IOSRTO-IOSWTO-1†Length(IOSWTO)-1.)‰DC.B…IOSSPT-IOSRTO-1†Length(IOSRTO)-1.)‰DC.B…IOSHDS-IOSSPT-1†Length(IOSSPT)-1.)‰DC.B…IOSTRK-IOSHDS-1†Length(IOSHDS)-1.)‰DC.B…IOSILV-IOSTRK-1†Length(IOSTRK)-1.)‰DC.B…IOSSOF-IOSILV-1†Length(IOSILV)-1.)‰DC.B…IOSPSM-IOSSOF-1†Length(IOSSOF)-1.)‰DC.B…IOSSHD-IOSPSM-1†Length(IOSPSM)-1.*‰DC.B…IOSTRKD-IOSSHD-1…Length(IOSPSD)-1.,‰DC.B…IOSPCOM-IOSTRKD-1„Length(IOSTRKD)-1.,‰DC.B…IOSSPTD-IOSPCOM-1„Length(IOSPCOM)-1.,‰DC.B…IOSSRTD-IOSSPTD-1„Length(IOSSPTD)-1.,‰DC.B…IOSEWCC-IOSSRTD-1„Length(IOSSRTD)-1.+‰DC.B…IOSECC-IOSEWCC-1…Length(IOSEWCC)-1.*‰DC.B…IOSDRSV-IOSECC-1…Length(IOSECC)-1.$‰DC.B…-1“End-of-tablesentinelbyte. '‰DS.W†0•Thisstatementensuresthatthe'*¦locationcounterisalignedtoaword%*¦boundaryeveniftheCONFGLENtable%*¦happenstocontainanoddnumberof*¦bytes. PAGE *H*ˆThisloop,whichisenteredatCNF200,processestheparameterfields.* 3CNF110ƒROR.W„#1,D2’BringthenextbitoftheIOSPRM&*¦fieldintobit15ofD2wherewecan*¦easilytestit. 1CNF120ƒTST.W„D2•Iftheparameter-maskbitisset,3‰BMI.S„CNF130theuserisspecifyingthisparameter3‰MOVE.Bƒ(A2),(A0)Œvalue.‚Otherwise,theuserisnot?CNF130ƒCMP.B„(A2)+,(A0)+Šspecifyingthisparametervalue,sowe4‰DBRA…D0,CNF120Œcopytheparameterfromtheexisting$*¦configurationintotheusertask's&*¦configureparameterblock.‚Thisloop$*¦processesonebyteatatimeuntil$*¦we'veprocessedallbyte(s)ofthe%*¦currentparameterfield.‚Noticethe)*¦useoftheCMP.Binstructiontoadvance*¦bothaddressregisters. /‰ADDQ.Wƒ#1,D1’AdvanceD1.Wtoindextothenext$*¦byteoftheCONFGLENtable.‚Recall)*¦thatwehadD1.W=0whencontrolfirst*¦enteredthisloop. ECNF140ƒMOVE.BƒCONFGLEN(PC,D1.W),D0ƒGetthenextentryoftheCONFGLEN,‰EXT.W„D0“tableintoD0.W.‚ThisvalueisN-15‰BGE.S„CNF110whereNisthenumberofbyte(s)inthe%*¦nextparameterfield.‚Ifwehaven't#*¦reachedthenegativeend-of-table&*¦sentinelentry,loopbacktoprocess*¦thenextparameterfield. &*¨NoticethatA0pointstotheIOSDRSV$*¦fieldoftheusertask'sconfigure(*¦parameterblockwhencontrolfallsout'*¦ofthisloop.‚Similarly,A2pointsto$*¦theIOSDRSVfieldoftheconfigure%*¦blockfortheconfigurationthatis*¦beingupdated. PAGE G*ˆNowwew anttochecktheproposedconfigurationtoseeifitcontainsK*‚anyinvalid‚orinconsistentconfigurationvalues.‚Ifitdoes,we'llabort#*‚withanappropriateerrorreport. 8CONERR43EQU†$43“TheinterleavefactorforaVME320disk<‰MOVEQBƒCONERR43,D3Šmustbebetween1andSectors/track-1.>EQ280„EQU†IOSILV-IOSDRSV‡IftheIOSILVparameterisn'tinthis:‰MOVE.BƒEQ280(A0),D0‰range,abortwithanerrorreport.‚If5‰BEQ.S„CNERROR1weaborthere,theerrorcodeinD3.B1‰ADD.B„#1,D0willbereturnedtotheusertaskin:EQ285„EQU†IOSSPT-IOSDRSV‡theIOSDSTfieldoftheconfigure$‰CMP.B„EQ285(A0),D0‰parameterblock.CNERROR1BGE†CONERROR 5CONERR44EQU†$44”TheVME320drivercontainscodethat;‰MOVEQBƒCONERR44,D3Šassumesthatthelogicalsectorsizeis&*¦anonzeromultipleofLCDSCTSZwhere>EQ290„EQU†IOSPSM-IOSDRSV‡LCDSCTSZisdefinedtobethelargest9‰MOVE.WƒEQ290(A0),D0‰commondivisorofallpossiblevalid5‰BEQ.S„CNERROR2sectorsizes.‚Herewechecktoverify'*¦thatthelogicalsectorsize(IOSPSM)#*¦isnonzero.‚Ifweaborthere,the(*¦errorcodeinD3.Bwillbereturnedto&*¦theusertaskintheIOSDSTfieldof *¦theconfigureparameterblock. ;‰MOVEQ.L‚#VDOSRSZ>>2,D1‰NowwegettheVersadosrecordsize3‰ASL.L„#2,D1intoD1.L,andwesettheIOSRECfield?EQ300„EQU†IOSREC-IOSDRSV‡oftheconfigureparameterblockequal;‰MOVE.WƒD1,EQ300(A0)‰totheVersadosrecordsize.‚Wesavea)*¦wordofmemoryherebytakingadvantage&*¦ofthefactthattheVersadosrecord *¦sizeisevenlydivisibleby4. 8EQ310„EQU†VDOSRSZ>>2IftheVersadosrecordsizeisever9EQ320„EQU†EQ310<<2changedsothatitisn'tamultipleof6‰IFNE…VDOSRSZ-EQ320ˆ4,wewanttogenerateanassembly/‰FAIL…0”[****ERROR****ERROR****ERROR****]-‰ENDCšerrortoalerttheconfusedmaintenance'*¦programmertotheproblemthatarises(*¦here.‚Theinstructionthatisnormally$*¦skippedheregeneratesanassembly)*¦erroriftheVersadosrecordsizeisn't*¦amultipleof4. PAGE .‰DIVU…D0,D1’Werequirethatthelogicalsector*‰SWAP…D1“size(inD0.W)evenlydividesthe(*¦Versadosrecordsize(inD1)sowecan)*¦translateanintegralnumberoflogical(*¦sector(s)intoaVersadosrecord.‚Here(*¦wegettheremainderfromthedivision(*¦intoD1.W,andwesavethequotientin*¦thetophalfofD1. >‰AND.W„#(1<‰BTSTW„#IOARDISC,EQ340(A0)‚logicalsectors.Determinerigidor2‰BNE.S„CNF150floppyfromthe#IOARDISCbitofthe4‰ADDQ.Lƒ#1,D5attributesword.‚Iffloppy,setD5=1=‰BTSTW„#IOADSIDE,EQ340(A0)‚forasingle-sideddisk.‚Determine1‰BEQ.S„CNF160theactualnumberofsidesfromthe1‰ADDQ…#1,D5#IOADSIDEbitoftheattributesword.*‰BRA.S„CNF160Ifdouble-sided,setD5=2. ;EQ350„EQU†IOSHDS-IOSDRSV‰Wehavearigiddisk,socalculate/CNF150ƒMOVE.BƒEQ350(A0),D5‰thenumberofheads. 5CNF160ƒMULU…D5,D2’ComputethetotalnumberoflogicalCNERROR3BLS.S„CONERRORfactthatthesectorsintrackzeroof'*¦adouble-densityfloppydiskareonly%*¦halfaslargeasnormalsectors.‚We)*¦nowhavethetotalcapacityofthedisk)*¦intermsoffull-sizedlogicalsectors.&*¦Ifthetotalcapacityofthediskin(*¦termsoffull-sizedlogicalsectorsis#*¦zeroorless,wereportanerror. !*¨Theinstructionthatislabeled%*¦CNERROR3isusedbyothercodeasa&*¦steppingstonesotheothercodecan&*¦gettoCONERRORwithouttheuseofa&*¦BLS.Linstructionintheothercode. 5CONERR47EQU†$47”Gettheerrorcodethatwe'llusetoEQ380„EQU†IOSRSZ-IOSDRSV‡Unfortunately,theresultingquotient:‰MOVE.WƒD2,EQ380(A0)‰canbea32-bitnumber,andthe680002‰MOVE.WƒD0,D2islimitedto16-bitquotients.‚This1‰DIVU…D1,D2codeperformsthedivisiontoyielda8‰MOVE.WƒD2,EQ380+2(A0)‡32-bitquotient,andwestorethe%*¦resultintotheIOSRSZfieldofthe(*¦usertask'sconfigureparameterblock.%*¦Wesimplydiscardtheremainder(if$*¦any),sotheusercan'taccess any$*¦partialVersadosrecordthatmight*¦existattheendofthedisk. %*¨Weperformthedivisionanalogously)*¦tothewayapersondoeslongdivision.)*¦Thedifferenceisthatweuseabaseof#*¦65,536insteadofbase10.‚Divide)*¦faultcan'toccuronthefirstdivision)*¦becausewereducethedividendtoa16-&*¦bitnumber.‚Dividefaultcan'toccur$*¦ontheseconddivisionbecausethe)*¦remainderinthetophalfofD2mustbe*¦lessthanthedivisor. 1‰IFEQ…VDOSRSZToguaranteethatdividefaultdoes/‰FAIL…0”[****ERROR****ERROR****ERROR****],‰ENDCšnotoccur,wemustassurethatVDOSRSZ"*¦isnonzero.‚Azerovalueforthe'*¦Versadosrecordsizeispreposterous,'*¦butweincludethistestforabsolute!*¦safety.‚Theinstructionthatis(*¦normallyomittedherewillgeneratean$*¦assemblyerrorifsomeonetriesto'*¦definetheVersadosrecordsizetobe*¦zero. PAGE G*ˆFinally,we'rereadytocopytheproposedconfigurationfromtheuserI*‚task's‚configure‚parameterblockintotheconfigureblockthatisbeing *‚updated. @‰MOVEQWƒIOSDRSV-IOSATW-1,D0„Allparametersandattributesinthe>CNF180ƒMOVE.Bƒ-(A0),-(A2)Šproposedconfigurationarevalid,so4‰DBRA…D0,CNF180Œcopytheproposedconfigurationinto#*¦theconfigureblockthatisbeing#*¦updated.‚Foraconfigurecommand,&*¦we'reupdatingthecurrentconfigure'*¦blockinthedrive'sareaoftheCCB,%*¦andforadefaultconfigurecommand&*¦we'reupdatingthedefaultconfigure'*¦blockinthedrive'sDCB.‚Noticethat)*¦wecopytheIOSATWfieldandallofthe)*¦parameterfields,butwedon'tcopythe%*¦maskfieldsbecausethemaskfields(*¦aren'treallypartofthetotaldevice*¦configuration. $*¨Attheconclusionofthisstep,A2#*¦pointstotheIOSATWfieldofthe'*¦configureblockthat'sbeingupdated,&*¦soA2issetproperlyforustocall*¦subroutineSTATCON1. /‰TST.L„(SP)“Recallthatthevalueontopofthe1‰BEQ.S„CNF200stackiszeroifwe'reperforminga(*¦defaultconfigurecommand.‚Weskipthe$*¦nextsectionofcodeforadefault&*¦configurecommand,andweexecuteit)*¦onlyforanordinaryconfigurecommand. PAGED*ˆThis‚section‚ofcode‚isexecutedonlyforaconfigurecommand,not"*‚foradefaultconfigurecommand. :‰MOVE.WƒD1,SCTPVREC(A1)ˆSetSCTPVREC<--VDOSRSZ/IOSPSMto(*¦indicatethenumberoflogicalsectors'*¦inaVersadosrecord.‚Recallthatthe(*¦desiredvaluewascomputedearlierand%*¦waskeptinD1.‚Weneedtoknowhow'*¦manylogicalsector(s)thereareina)*¦Versadosrecordsowecanmakethedisk(*¦appeartocontainVersadosrecords.‚We"*¦don'twanttosetSCTPVRECfora#*¦defaultconfigurecommandbecause%*¦SCTPVRECiseffectivelypartofthe)*¦drive'scurrentconfiguration,notpart'*¦ofthedrive'sdefaultconfiguration. 7‰MOVE.WƒIOSOPT(A4),D0ŠIftheentireIOSOPTfieldofthe3‰BNE.S„CNF190IOCBiszero,settheMOUNTEDflagto8‰ST.B…MOUNTED(A1)Šindicatethatthediskisnowmounted.(*¦AconfigurecommandwithazeroIOSOPT(*¦fieldisdefinedtobeaconfigureand*¦mountcommand. >CNF190ƒROL.W„#15-IOPDMNTB,D0ˆIftheIOPDMNTBbitoftheIOSOPT1‰BPL.S„CNF200fieldoftheIOCBisset,clearthe9‰CLR.B„MOUNTED(A1)ŠMOUNTEDflagtoindicatethatthedisk(*¦isnowdismounted.‚Aconfigurecommand(*¦withthisoptionbitsetisdefinedto&*¦beaconfigureanddismountcommand. 5‰ST.B…DCBCCF(A3)Inthecaseofadismountcommandwe(*¦settheDCBCCFflaginthedrive'sDCB'*¦toindicatethattheoperatingsystem(*¦shouldreturnthedrivetoitsdefault*¦configuration. PAGE@*ˆControl‚converges‚here‚for‚both‚configure‚commands‚anddefault*‚configurecommands. 7CNF200ƒBSR†STATCON1WecallsubroutineSTATCON1hereto)*¦updatetheIOSDST(device-status)field'*¦andtheIOSDTP(device-type)fieldin%*¦theusertask'sconfigureparameter'*¦block.‚Thedevice-statusfieldshould'*¦reflectthedisk'smounted/dismounted&*¦status,whichmayhavejustchan ged,"*¦andthedevice-typefieldshould(*¦reflectthedevicetypethatisspeci-#*¦fiedbytheattributewordinthe%*¦configurationthatwejustchanged. '*¨NoticethatwestillhaveD6pointing(*¦totheusertask'sconfigureparameter)*¦blockwhenwecallsubroutineSTATCON1,'*¦andalsonoticethatwehaveregister(*¦A2pointingtotheIOSATWfieldofthe'*¦configureblockthat'sbeingupdated.!*¦RecallthatsubroutineSTATCON1(*¦destroysD5,buttheoriginalvalueof*¦D5isstillonthestack. 8‰MOVEM.L‚(SP)+,D5/D6ŒRestoreD5andD6,whichweresaved&*¦atthebeginningofthisroutine.‚We'*¦nowhaveD5=0ifwe'reprocessinga)*¦defaultconfigurecommand,orD5=1if'*¦we'reprocessingaconfigurecommand.'*¦WealsohaveD6=DCBCDV,thechannel%*¦devicenumberofthedevicethatis*¦beingconfigured. 8‰TST.B„MOUNTED(A1)ŒIfwe'reprocessingaconfigure&mount4‰BEQ†CMDEXIT1command,weneedtosendarecalibrate.‰TST.L„D5“(seek)command‚tothecontroller.‚If2‰BEQ†CMDEXIT1we'reprocessingadefaultconfigure2‰MOVEQ.L‚#0,D3command,we'refinishedandweneed6‰BRA.S„CNFGSEEKtogoqueueanI/Ocompletioneventto*¦theattachedtask. PAGE O*********************************************************************************ˆCONFIGURATIONERRORROUTINE*E*ˆControlcomestothisroutinewhen‚itisnecessarytoabortwithanE*ˆerrorcodefromanyconfigurationcommand.‚ErrorcodesintherangeC*ˆ$01to$3F‚areuniversal.‚Errorcodesintherange‚$40to$7Fare*ˆuniquetothisdriver.*!*ˆEntry:„D3=Detailederrorcode<*’D6=Physicaladdressofuser'staskconfigurepara.block*!*ˆRegisterusage:…01234567 *™D„Rƒ*…**™A‚**2*ˆExit:…Branchestocommonexitroutine(CMDEXIT).*O******************************************************************************* CONERROR: 2‰MOVE.LƒD6,A0’Putthedetailederrorcodeintothe5‰MOVE.BƒD3,IOSDST(A0)ˆIOSDSTfieldoftheusertask's9‰MOVEQBƒISTACNF,D1‹configureparameterblock,andthengo4‰BRA†CMDEXIT2tothecommandprocessor'scommonexit(*¦routinewithD1.Bsetuptoreportthe#*¦majorerrorcodethatindicatesa*¦configurationerror. $*¨Noticethatwedon'tneedtoworry)*¦aboutcleaningupthestackbecausethe)*¦commonexitroutinecleansupthestack!*¦byrestoringthestackpointer. PAGE O********************************************************************************1*ˆREAD,WRITE,FORMATANDCONFIGURE-SEEKCOMMANDS*=*ˆTheread,write,and‚format‚and‚configure-seekcommandsareA*ˆthesupported‚commandswhichrequireaECApackettobecreated?*ˆfortheparticularcommandbeforewecanqueuethecommandto<*ˆthecontrollerboard.‚Forthis‚reason,‚mostofthecodeis>*ˆsharedbetweenthesecommands.Theconfigure-seekcommandisB*ˆenteredfromtheconfigureroutineaboveandtheread,writeand@*ˆformatcommandsenterheredirectlyfromthecommandswitching*ˆtable.*6*ˆEntry:„A1=Pointertodrive'svariableblockinCCB*’A3=PhysicaladdressofDCB*’A4=PhysicaladdressofIOCB*’A5=PhysicaladdressofCCB/*’A6=PhysicaladdressofTCBofattachedtask*0*’D5=0‚orI/OfunctioncodeforConfigure-seek3*’D6=Channeldevice#forthediskdrive(DCBCDV)*!*ˆRegisterusage:…01234567*™D‚********™A‚******P*2*ˆExit:…Branchestocommonexitroutine(CMDEXIT).*O******************************************************************************* READCMD: @‰MOVEQ.L‚#READFUNC-WRTFUNC,D5ƒControlentersatthisentrypoint(*¦whenwe'vereceivedareadcommand.‚We$*¦setupD5.Lsoitwillcontainthe#*¦value+2whencontrolreachesthe$*¦commoncommand-processingroutine.(*¦Thevalue+2meansthatareadcommand*¦isbeingprocessed. >WRITECMDSUB.L„#-WRTFUNC,D5‹Controlentersatthisentrypoint&*¦whenwe'vereceivedawritecommand.$*¦WesetD5.Lsoitwillcontainthe&*¦value-1whencontrolfallsintothe$*¦commoncomma nd-processingroutine.)*¦Thevalue-1meansthatawritecommand*¦isbeingprocessed. .FORMATƒEQU†*–Controlcomestothisentrypoint'*¦whenwe'vereceivedaformatcommand.(*¦WeleaveD5.Lalonebecauseitalready&*¦containsthevaluezero,whichindi-&*¦catesthataformatcommandisbeing*¦processed. PAGE8‰MOVEQBƒISTADNM,D1Ifthediskthatisbeingaccessedis6‰TST.B„MOUNTED(A1)Šnotmounted,rejectthecommandand3‰BEQ†CMDEXIT2returnanerrorcodetoindicatethat#*¦thediskisnotmounted.‚Wedon't&*¦allowtheusertoaccessthediskif"*¦thediskisn'tmounted.‚Ifwe're"*¦performingaconfigureandmount$*¦command,thediskhasalreadybeen%*¦mountedbythetimecontrolreaches(*¦thispoint.‚Ifthediskisn'tmounted,(*¦theusercanemploytheVersadosmount*¦commandtomountit. 7‰MOVE.LƒIOSRRN(A4),D3ŠGetthespecifiedVersadosrecord'*¦numberfromtheusertask'sIOCBinto(*¦D3.‚Noticethatthenumberwegethere(*¦isaVersadosrecordnumber,andwe'll%*¦laterneedtotranslatethatnumber(*¦intoalogicalsectornumber.‚Versados)*¦recordsdon'tnecessarilycorrespondto(*¦logicalsectorsonaone-to-onebasis. 0CNFGSEEKEQU†*–Controlcomestothisentrypoint)*¦toprocessaseek(recalibrate)command(*¦forcompletionofaconfigurecommand.&*¦WehaveD3=0uponentrytoprovide%*¦adummyVersadosrecordnumberthat$*¦willpassallvaliditychecks,and"*¦D5contains+1toindicatewe're*¦processingaconfigure-seek. 5‰LEA†IOPKTEND(A1),A2ˆPointA2tothewordimmediately$*¦followingthelastwordoftheI/O#*¦packetinthedrive'sareaofthe&*¦drive-associatedportionoftheCCB."*¦We'lluseA2withauto-decrement&*¦addressingtofillintheI/Opacket%*¦valuesthatdescribetheI/Otrans-!*¦actionthatisbeingrequested. &*¨[******Warning******]‚Weuseauto-&*¦decrementaddressinginthisroutine'*¦insteadofreferringtofieldsinthe)*¦I/Opacketbytheirnames,sotheorder(*¦inwhichthefieldsofthedrive'sI/O(*¦packetaredefinedmustnotbealtered)*¦withoutfirstconsideringthisroutine. PAGE =‰MOVE.LƒCCBTASKA(A5),A0ˆPointA0totheTCBthatcontrolsthe%*¦taskthatownstheIOCBfortheI/O%*¦commandthatisbeingprocessed.‚If(*¦thecommandthatisbeingprocessedis&*¦anordinarycommandthatrequiresan)*¦I/Obuffer,thetaskthatownstheIOCB*¦alsoownstheI/Obuffer. <‰MOVE.WƒIOSOPT(A4),-(A2)‡CopytheI/Ooptionsfieldfromthe3L1‡SET†IOOPTSIOCBintotheI/Opacket.‚Ifthesign0‰BPL.S„RW120bitoftheIOSOPTfieldisset,the&*¦IOCBincludesanIOSTSKfieldandan(*¦IOSSESfield.‚Thesefieldscanbeused&*¦byasystemtasktospecifythetask)*¦thatownstheI/Obufferwhenthattask)*¦isn'tthesametaskthatownstheIOCB.'*¦TheIOSTSKfieldandtheIOSSESfield(*¦shouldneverbeincludedwithaformat%*¦commandoraconfigure-seekƒcommand(*¦becauseneitheraformatcommandnora#*¦configure-seekƒcommandhasanI/O *¦buffer. '*¨NoticetheuseoftheSETinstruction)*¦togenerateaconcordanceentryforthe *¦IOOPTSfieldthatissethere. '*¨WecopyfieldsfromtheIOCBintothe'*¦I/Opacketfortwoimportantreasons.&*¦(1)‚Wewantthefieldstobequickly&*¦accessibletotheinterrupthandler.'*¦(2)‚ThetaskthatownstheIOCBmight)*¦continueexecutionwhiletheI/Otrans-&*¦actionisbeingdoneunderinterrupt)*¦control,andthetaskmightchangesome%*¦ofthevaluesintheIOCB.‚Sincewe)*¦can'ttrusttheintegrityofthefields(*¦intheIOCB,wemakeourowncopiesof&*¦theonesweneed.‚Thustheinterrupt&*¦handlerwon'trunamokbyusingIOCB'*¦valuesthatcouldcapriciouslychange*¦atrandomtimes. PAGE B*ˆThis‚sectionof‚code‚isexecutedonly‚when‚theIOCBincludestheI*‚optionalIOSTSKandIOSSESfields.„Thesefieldsdesignatethe‚taskthatL*‚owns‚theI/ObufferwhenthetaskthatownstheIOCBisasystemtaskthat*‚doesn'towntheI/Obuffer. 6‰LEA†IOSTSK(A4),A0ŠWeneedtogetapointertotheTCB5‰MOVE.LƒA1,-(SP)thatcontrolsthetaskthatownsthe7‰MOVE.Lƒ#T0GETTCB,D0‰I/Obuffer.‚TheT0GETTCBexecutive/‰TRAP…#EXECrequestusesA0asapointertotheú4 8;7"6*527:5B5J4R7Z5b7j;r=z;‚,Š’4šA¢9ª=²>º7Â8Ê0Ò7Ú8â:ê74‰BRA.S„RW110IOSTSK/IOSSESpacket,anditreturnsA0)*¦withapointertotheTCBthatcontrols"*¦thespecifiedtask.‚TheT0GETTCB(*¦executiverequestdestroysA1,D0,D1,)*¦andD2,butwepreservethevalueofA1$*¦bysavingitonthestack.‚Control%*¦returnsfromtheT0GETTCBexecutive(*¦requesttotheinstructionimmediately&*¦followingtheTRAPinstructionifno*¦errorsaredetected. 4RW100„BRA†BADBUFADControlreturnsfromtheT0GETTCB(*¦executiverequesttothispointifthe'*¦specifiedtaskdoesn'texist.‚Inthis%*¦case,wereportanerrorindicating$*¦thatthespecificationfortheI/O%*¦bufferisbad.‚Noticethatwedon't(*¦needtocleanupthestackbecausethe*¦errorroutinecleansitup. '*¨Controlmaybranchtothispointfrom(*¦belowinoneormorecasestomakethe*¦samekindoferrorreport. 8RW110„MOVE.Lƒ(SP)+,A1RestoreA1topointtothedrive's)*¦areaofthedrive-associatedportionof *¦theCCB. PAGE:RW120„MOVE.BƒD6,-(A2)CopythedrivenumberfromD6.Binto6‰MOVE.BƒD5,-(A2)theDRIVENUMfieldoftheI/Opacket,5L1‡SET†DRIVENUMcopythefunctionflagfromD5.Binto3L1‡SET†IOFUNCTŽtheIOFUNCTfieldoftheI/Opacket. '*¨NoticetheuseoftheSETinstruction)*¦togenerateconcordanceentriesforthe*¦fieldsthatwemodifyhere. $*¨Theinterrupthandlercouldeasily(*¦determinethedrivenumberforitself,$*¦butweimprovespeedbymakingthe(*¦drivenumberdirectlyavailableinthe(*¦I/Opacket.‚TheIOFUNCTfieldcontains *¦+2forareadcommand,0fora#*¦formatcommand,or-1forawrite *¦command. *B*ˆOffsetIOSALT=IOSSADholdsthesectornumberforthe‚alternate=*ˆsector(alsoequaltothesectornumberofthebadsector),;*ˆandwewanttosaveitinIOBUFLOC=IOALTSEC,sowewill@*ˆputIOSSADintoD6alittleearlier,thenskipovertheLOGPHY *ˆroutine.*<‰MOVE.LƒIOSSAD(A4),D6ˆD6<--‚physicaladdressofI/Obuffer. 1‰ASR.L„#1,D5’Ifwe'reprocessingaformatcommand2‰BEQ.S„RW130oraconfigure-seekcommand,clearD5&*¦andskipthesectionthatdetermines'*¦theaddressandthelengthoftheI/O&*¦buffer.‚ThereisnoI/Obufferfora$*¦formatcommandoraconfigure-seek'*¦command.‚ThezerothatwegetintoD5%*¦herewillbeusedlatertoindicate(*¦thatthebufferlengthforaformator!*¦configure-seekcommandiszero. %*¨Controlfallsthroughhereifwe're%*¦processingareadorwritecommand. @*******‚MOVE.LƒIOSSAD(A4),D6ŠGetthephysicaladdressoftheI/O<‰MOVE.LƒIOSEAD(A4),D5ˆbufferintoD6,andgetthelength(in.‰SUB.L„D6,D5bytes)oftheI/ObufferintoD5.4‰ADD.L„#1,D5SubroutineLOGPHYrequiresthebuffer's0‰BSR†LOGPHYlogicaladdressanditslengthinD6&*¦andD5asinputs,andthesubroutine(*¦alsoassumesthatA0pointstotheTCB&*¦thatcontrolsthetaskthatownsthe#*¦I/Obuffer.‚RecallthatwesetA0(*¦earlier.‚SubroutineLOGPHYreturnsthe)*¦buffer'sphysicaladdressinD6,andit *¦preservestheotherregisters. PAGE%*¨IfthespecifiedI/Obufferdoesn't$*¦residewithinthespecifiedtask's'*¦memoryarea,subroutineLOGPHYaborts"*¦withanerrorreport.‚Subroutine)*¦LOGPHYalsoabortswithanerrorreport(*¦ifthebufferlengthiszerooranodd *¦number. D*ˆWhencontrolreachesthispoint,theregistersaresetasfollows: *‚A6ƒ=TCBofattachedtask.*‚A5ƒ=CCB.*‚A4ƒ=IOCB.*‚A3ƒ=DCB.-*‚A2ƒ=PointertoIOOPTSfieldofI/OPacket.C*‚A1ƒ=DiscDrive'svariableblockindrive-associated areaofCCB.F*‚A0ƒ=TCBoftaskthatownstheI/ObufferifthereisanI/Obuffer.=*‡=TCBoftaskthatownstheIOCBifthereisnoI/Obuffer. C*‚D6.L=PointertoI/OBufferifthereisone.‚Otherwise,garbage.=*‚D5ƒ=Buffersizeinbytesifthereisone.‚Otherwise,zero.*‚D4ƒ=Scratch.*‚D3.L=IOSRRN*‚D2ƒ=Scratch.*‚D1ƒ=Scratch.*‚D0ƒ=Scratch. PAGE *A*ˆCalculatethetotalnumberofVERSAdosrecordstobeprocessed.* BRW130„MOVE.LƒD5,IOBUFLEN(A1)ˆDividethebuffersize(inD5)bythe?EQ400„EQU†CONFGBLK+IOSREC†Versadosrecordsize.‚Thequotientin<‰DIVU.WƒEQ400(A1),D5‰D5.WtellsushowmanyVersadosrecords'*¦weneedtoprocess,andtheremainder&*¦inthetophalfofD5shouldbezero)*¦becausewedon'tallowanyI/Otransfer"*¦thatinvolvesapartialVersados *¦record. '*¨Wedon'tneedtoworryaboutdividing#*¦byzeroherebecausetheVersados$*¦recordsizeisanonzeroconstant.(*¦Furthermore,weknowthattheVersados)*¦recordsizeinthedisk'sconfiguration&*¦blockisvalidbecausewe'vealready"*¦checkedtomakesurethediskis$*¦mounted,andthediskismarkedas)*¦beingmountedonlyatthecompletionof)*¦asuccessfulconfigure/mountoperation. &*¨Ifanoutrageouslylargebuffersize)*¦causesdividefault,thetophalfofD5'*¦willendupwithanonzerovalue;and)*¦we'llcheckforthaterrormomentarily. &*¨Foraformatcommandoraconfigure-$*¦seekcommandwehaveD5=0,sowe&*¦getazeroquotienttoindicatethat*¦thereisnodatatransfer. 1‰MOVEQ.L‚#0,D2’MovethecountofVersadosrecords2‰MOVE.WƒD5,D2intoD2,andreportabuffer-address4‰CMP.L„D5,D2errorifthetophalfofD5isnonzero.1‰BNE.S„RW100ThetophalfofD5canbenonzeroin$*¦oneoftwoways.‚Eitherthebuffer(*¦sizeisn'tanintegralmultipleofthe#*¦Versadosrecordsize,orelsethe)*¦buffersizeissolargethatitexceeds)*¦thecapacityof65,535Versadosrecords$*¦(i.e.,16,776,960bytes).‚Withthe)*¦presentleveloftechnologythereisno'*¦needtoallowasingleI/Ocommandto(*¦specifyatransferofmorethan65,535*¦Versadosrecords. '*¨D2nowcontainsacountofthenumber&*¦ofVersadosrecordstobeprocessed.)*¦We'lllaterneedtoconvertthatnumber"*¦intoacountoflogicalsectors. PAGE *E*ˆDeterminewhetherthestartingVERSAdosrecordnumberisbeyondthe<*ˆendofthedisk.‚SetupD1totheappropriatestatuscode.*;EQ410„EQU†CONFGBLK+IOSRSZˆNowchecktoseeifthespecified6‰MOVE.LƒEQ410(A1),D0‰Versadosrecordnumber(inD3)is2‰SUB.L„D3,D0beyondtheendofthedisk,andabort/‰BLS.L„RW190withanerrorreportifitis.‚The#*¦userhasaseriousproblemifthe)*¦specifiedstartingrecordisbeyondthe%*¦endofthedisk.‚RecallthatIOSRSZ(*¦specifiesthetotalnumberofVersados'*¦recordsavailableontheentiredisk.&*¦Sincetherecordnumberofthefirst&*¦recordiszero,therecordnumberof)*¦thelastVersadosrecordonthediskis*¦IOSRSZ-1. !*¨Foraconfigure-seekƒcommandwe)*¦haveD3=0,sotheerrorcheckthatwe(*¦makeheredegeneratesintoaNOPfora*¦configure-seekƒcommand. '*¨NoticethatwenowhaveD0.Lequalto)*¦thenumberofVersadosrecordsthatare$*¦availablefromthestartingrecord*¦throughtheendofthedisk. 7‰MOVEQBƒISTAOK,D1ŽInitializeD1.Btocontainthestatus1‰CMP.L„D0,D2codethatisusedwheneverythingis4‰BLS.S„RW135OK,andthenchecktoseeiftherecord&*¦countexceedsthenumberofVersados(*¦recordsthatareavailablebetweenthe$*¦startingrecordandtheendofthe#*¦disk.‚RecallthatD2containsthe)*¦specifiedcountofVersadosrecordsfor'*¦theI/OtransferandthatD0contains&*¦acountoftheVersadosrecordsthat(*¦areavailablefromthestartingrecord%*¦throughtheendofthedisk.‚D2=0&*¦foraformatcommandoraconfigure-*¦seekcommand. PAGE 8‰MOVEQBƒISTAEOV,D1TheproposedI/Otransfergoesbe yond)*¦theendofthedisk,sogettheend-of-(*¦volumeerrorcodeintoD1.B.‚We'lluse'*¦thaterrorcodeasthestatusthatwe)*¦returntotheuserifwedon'truninto%*¦anothererrorthatismoreserious. %*¨ThereareroutinesinVersadosthat(*¦dependonustoreturnthisparticular(*¦errorcodewhenanI/Otransferstarts'*¦atalegalVersadosrecordnumberbut%*¦extendsbeyondtheendofthedisk.'*¦Forexample,theutilityprogramthat)*¦initializesadiskkeepswritingtothe)*¦diskuntilitreceivesthiserrorcode. .‰MOVE.WƒD0,D2’ChangetherecordcountinD2to5‰MULU…EQ400(A1),D2‰equalthetotalnumberofVersados;‰MOVE.LƒD2,IOBUFLEN(A1)†recordsthatareavailablefromthe5‰MOVEQ.L‚#0,D2startingrecordthroughtheendofthe4‰MOVE.WƒD0,D2disk.‚We'lldoasmuchofthetransfer)*¦aspossible,andwe'lltruncateitwhen*¦wereachtheendofthedisk. '*¨WeknowthatthevalueinD0willfit&*¦intoa16-bitfieldbecausewefound'*¦abovethatD0waslessthanD2andwe&*¦alreadyknewthatthetophalfofD2*¦waszero. 6RW135„MOVE.BƒD1,-(A2)SettheEOVFLAGfieldoftheI/O(*¦packet.‚Thevaluethatweputintothe$*¦EOVFLAGfieldiseithertheISTAOK)*¦statuscodeortheISTAEOVstatuscode.'*¦WeusetheISTAEOVstatuscodeifthe(*¦I/Otransferasitwasspecifiedwould'*¦havegonebeyondtheendofthedisk.%*¦Otherwise,weusetheISTAOKstatus!*¦code.‚Ifwedon'tencounterany)*¦seriouserrorsduringtheI/Otransfer,)*¦we'llreturnthevaluefromtheEOVFLAG'*¦fieldoftheI/Opacketasthestatus*¦codeforthetransaction. PAGE*3*ˆConverttheVERSAdosrecordsintologicalsectors* 7‰MOVE.WƒSCTPVREC(A1),D0ˆGetthenumberofsector(s)per2‰MULU.WƒD0,D2VersadosrecordintoD0,andconvert'*¦thecountofVersadosrecords(inD2)%*¦intoacountoflogicalsectors.‚D2'*¦nowtellsushowmanylogicalsectors%*¦toprocess.‚Theuseofthemultiply)*¦instructionhereiscorrectbecausethe'*¦countofVersadosrecordsinD2wasa%*¦16-bitnumber,nota32-bitnumber.(*¦Theresultingcountoflogicalsectors*¦inD2isa32-bitnumber. 0‰MOVEQ.L‚#0,D4’HerewesetD4<--D3*SCTPVRECto'*¦starttheconversionofthespecified7RW140„ADD.L„D3,D4Versadosrecordnumberintoalogical-‰BCS.S„RW190sectornumber.‚We'reeffectively3‰SUB.W„#1,D0multiplyingtheVersadosrecordnumber4‰BHI.S„RW140bythenumberoflogicalsector(s)ina&*¦singleVersadosrecord,butwecan't(*¦useamultiplyinstructionbecausethe$*¦Versadosrecordnumberisa32-bit'*¦unsignednumber,nota16-bitnumber.)*¦IftheresultingvalueinD3exceeds32&*¦bits,weabortwithanerrorbecause *¦theIOSRRNvalueistoolarge. SPC 10&*ˆTheregistersaresetupasfollows: 9*‚A2=PointertoEOVFLAGfieldofthedrive'sI/Opacket(*‚A1=Drive'svariableblockintheCCB %*‚D4=Startinglogicalsectornumber&*‚D3=StartingVERSAdosrecordnumber*‚D2=Countoflogicalsectors*‚D1=Statuscode*‚D0=Scratch PAGE*0*ˆCheckforarigiddiskandsetDriveTypeCode*?EQ420„EQU†CONFGBLK+IOSATWˆIfthediskthatisbeingaccessedis@‰BTSTW„#IOARDISC,EQ420(A1)‚arigiddisk,wecanskiptherestof1‰BEQ.S„RW150theconversionroutine.‚Arigiddisk;‰MOVE.Bƒ#TYPE2,-(A2)‰isalwaysrecordedatthesamedensity2‰BRA.S„RW210throughoutthedisk.Wealsosavethe'*¦drivetypecodeinI/Opacket(weuse*¦harddiskwithECCalways). *E*ˆCheckforasingledata-densityfloppydiskandsetDriveTypeCode*DRW150„BTSTW„#IOADDEN,EQ420(A1)…Ifthediskthatisbeingaccessedis2‰BNE.S„RW160asingledata-densityfloppydisk,D4(*¦nowcontainsthelogicalsectornumber#*¦thatcorrespondstothespecified)*¦Versadosrecordnumber,andwecanskip%*¦therestoftheconversionroutine. 8‰MOVE.Bƒ#TYPE0,-(A2)‹Herewesavethedrivetypecodein;‰BTSTW„#IOASIZE,EQ420(A1)ƒtheI/Opacket.Weknowthemedia0‰BNE.S„RW210issingle-densitysothedrivetype9‰M OVE.Bƒ#TYPE4,(A2)Šcodeissetfor8"single-density.‚We0‰BRA.S„RW210testthesizebitoftheattributes(*¦wordandchangethedrivetypecodeif*¦themediaisactually5.25". *1*ˆConversionfordoubledata-densityfloppydisks*:RW160„MOVE.Bƒ#TYPE1,-(A2)‹Weknowwehaveadouble-density?‰BTSTW„#IOASIZE,EQ420(A1)ƒfloppydiskandwesetthedrivetype0‰BNE.S„RW170codeaccordinglyassumingitsan8"5‰MOVE.Bƒ#TYPE5,(A2)Šfloppy.‚Wetestthedisksizebit'*¦oftheattributeswordandchangethe$*¦drivetypecodeifactually5.25". 4RW170„MOVEQ.L‚#0,D0’Onadouble-densityfloppydisk,THENfactthatthesectorsintrackzeroare1‰MOVE.LD0,D2’onlyhalfsectors.‚Thesectorsthat)‰ENDIšprecedethestartinglogicalsector(*¦numberwereoriginallycountedasfull)*¦sectors,butthey'reonlyhalfsectors.'*¦Overflowisnotpossibleherebecause(*¦thevalueofD4hasalreadybeenfound#*¦tobelessthanaone-bytevalue. $*¨BesidesadjustingD4here,wealso)*¦setD0equaltothenumberoffull(not(*¦half)sectorsintrackzerobeyondthe*¦specifiedstartingsector. 0‰CMP.L„D0,D2’RecallthatD2.Lcontainsthecount/‰BHI.S„RW180offullsectorsfortheentireI/O2‰MOVE.LƒD2,D0transfer.‚IftheentireI/Otransfer2‰BRA.S„RW220willbewithintrackzero,weneedto5RW180„ADD.L„D0,D2doublethesectorcount.‚IftheI/O3‰BCC.S„RW220transferwillextendbeyondtheendof'*¦trackzero,however,wemustincrease(*¦thesectorcountbythenumberoffull(*¦sectorsthatwillbeaccessedintrack(*¦zero.‚Ineithercase,wechecktomake'*¦surethatoverflowdoesn'toccurwhen*¦weadjustthesectorcount. '*¨NoticethatD0.Lnowcontainsacount)*¦ofthenumberoffullsectorsthatwill(*¦beaccessedintrackzero.‚Thisnumber(*¦isequaltohalfofthenumberofhalf(*¦sectorsthatwillbeaccessedintrack*¦zero. PAGE‰MOVE.BƒDRIVTYPE(A1),D2†D2<--Drivetype(keepforreference)‰MOVE.BƒD2,DRVTYPE(A2) PAGE***¤NUMBEROFSURFACES:‰CLR.L„D0“*=EQ460„EQU†CONFGBLK+IOSATW†Determineifthisisaharddiskor@‰BTSTW„#IOARDISC,EQ460(A1)‚floppydiskfromtheattributesword. &‰IF‡THENŒIfwe'reaharddisk....EQ470„EQU†CONFGBLK+IOSHDS†*5‰MOVE.BƒEQ470(A1),D0‰PutthenumberofheadsintoD0. ‰ELSEšIfwe'reafloppydisk....6‰MOVEQ.L‚#1,D0PutdefaultvalueofonesurfaceinD0.?‰BTSTW„#IOADSIDE,EQ460(A1)‚Determineactualnumberofsurfaces.6‰IF‡THENŒIfattributeswordindicates2surfaces.0‰MOVEQ.L‚#2,D0Changenumberofsurfacestotwo.‰ENDI‰ENDI;‰MOVE.BƒD0,NUMSURF(A2)‡PutthenumberofsurfacesintoECA.7‰MOVE.WƒD0,SURF(A1)ŠStorenumberofsurfacesindrive's!*¦variableblockforeasyaccess. SPC 2***¤SECTORSPERTRACK:EQ480„EQU†CONFGBLK+IOSSPT†*;‰MOVE.BƒEQ480(A1),D0‰PutnumberofsectorspertrackinD0.5‰MOVE.BƒD0,NUMSPT(A2)ˆPutnumberofsectorsintoECA.5‰MOVE.WƒD0,SPT(A1)‹Storenumberofsectorsindrive's!*¦variableblockforeasyaccess. SPC 2"***¤HEADSET/LOADTIMESFOR5-1/4"‰BTST…#2,D2.‰IFTHEN’Executefordrivetypes4and5:5ŠMOVE.Lƒ#SETTM_5,D0‰D0<--headsettlingtimeinmsec3ŠASL.B„#1,D0D0<--settlingtimein500usecunits.ŠMOVE.BƒD0,HEADSET(A2)†WritetotheECAblock.0ŠMOVE.Lƒ#LDTM_5,D0ŠD0<--headloadtimeinmsec3ŠASL.B„#1,D0D0<--settlingtimein500usecunits/ŠMOVE.BƒD0,HEADLOAD(A2)…WritetotheECAblock.ŠBRA.S„STEP_RATE‰ENDI SPC 2%***¤HEADSET/LOADTIMESFORHARDDISK‰BTST…#1,D2 ‰IF‡THEN6ŠMOVE.Lƒ#SETTM_HD,D0ˆD0<--headsettlingtimeinmsec3ŠASL.B„#1,D0D0<--settlingtimein500usecunits1ŠMOVE.BƒD0,HEADSET(A2)†PutitintotheECAblock.1ŠMOVE.Lƒ#LDTM_HD,D0‰D0<--headloadtimeinmsec4ŠASL.B„#1,D0D0<--headloadtimein500usecunits2ŠMOVE.BƒD0,HEADLOAD(A2)…PutitintotheECAblock.ŠBRA.S„STEP_RATE‰ENDI PAGE***¤HEADSET/LOADTIMESFOR8"5‰MOVE.Lƒ#SETTM_8,D0ŠD0<--headsettlingtimeinmsec3‰ASL.B„#1,D0D0<--settlingtimein500usecunits1‰MOVE.BƒD0,HEADSET(A2)‡PutitintotheECAblock.0‰MOVE.Lƒ#LDTM_8,D0‹D0<--headloadtimeinmsec4‰ASL.B„#1,D0D0<--headloadtimein500usecunits2‰MOVE.BƒD0,HEADLOAD(A2)†PutitintotheECAblock. STEP_RATE SPC 2***¤HEADSTEPPINGRATE9‰MOVE.BƒCONFGBLK+IOSSRTD(A1),D0ƒD0<--Steppingratecode‰BTST…#1,D2 ‰IF‡THEN9‰LEA†SRHCODE(PC),A0‡A0<--pointertostepratesforhard‰ELSE;‰LEA†SRFCODE(PC),A0‡A0<--pointertostepratesforfloppy‰ENDI ,‰MOVE.Bƒ(A0,D0),D0‹D0<--Steppingratecode9‰BTSTW„#IOARDISC,CONFGBLK+IOSATW(A1)‚Testforfloppydisk ‰IFTHEN8‰BTSTW„#IOASIZE,CONFGBLK+IOSATW(A1)‚Testthefloppysize%‰IFTHEN’Executefor5.25"only:-‰ASL.B„#1,D0Doublethesteppingrateinmsec‰ENDI‰ENDI&‰ASL.B„#1,D0Convertto500usecunits2‰MOVE.BƒD0,STEPRATE(A2)†PutitintotheECAblock. SPC 2 ***¤SEEKTYPE5‰IF‡THENŒAzerostepratedefinesbufferedseek:9‰MOVE.B#BUFFSEEK,SEEKTYPE(A2)PutitintotheECAblock.-‰ELSEšA non-zerostepratedefinesstepseek:9‰MOVE.B#STEPSEEK,SEEKTYPE(A2)PutitintotheECAblock.‰ENDI SPC 2$***¤PRECOMPENSATIONCYLINDERNUMBER:>EQ490„EQU†CONFGBLK+IOSPCOM†CopytheprecompensationvaluefromD‰MOVE.WƒEQ490(A1),PRECOMP(A2)thedrive'svariableblocktotheECA. PAGE&***¤LOW-WRITECURRENTCYLINDERNUMBER:EQ505„EQU†CONFGBLK+IOSPSM†Storethenumberofbytespersector@‰MOVE.WƒEQ505(A1),BPS(A1)„indrive'svar.blockforeasyaccess. SPC 2*.*SETTHETRACKFORMATFIELDSINTHEECABLOCK*?*ˆ+-----------------------------+-----------------------------+'*‚$20ƒ|‡N0-Reserved‰|ˆN1-Reservedˆ|?*ˆ+-----------------------------+-----------------------------+'*‚$22ƒ|‡N2-Reserved‰|ˆN3-Reservedˆ|?*ˆ+-----------------------------+-----------------------------+,*‚$24ƒ|†N4-Post-DataGap…|ˆN5-Reservedˆ|?*ˆ+-----------------------------+-----------------------------+(*‚$26ƒ|†SectorLengthCode…|‹FillByte‰|?*ˆ+-----------------------------+-----------------------------+* ‰CMP.B„#0,D2 '‰IFTHEN’Executefordrivetype0:2‰LEA†FORMATS(PC),A0‡Single-density8"floppydisk.9‰MOVE.Lƒ(A0),N4(A2)ŠGetthefieldsfromthelinkANDfrom8‰MOVE.Lƒ#FRMT_SD,D0Šconstantsattheendofdrivercode.,‰MOVE.BƒD0,N4(A2)ŒPutitintotheECAblock.‰ENDI ‰CMP.B„#1,D2 '‰IFTHEN’Executefordrivetype1:2‰LEA†FORMATD(PC),A0‡Double-density8"floppydisk.9‰MOVE.Lƒ(A0),N4(A2)ŠGetthefieldsfromthelinkANDfrom8‰MOVE.Lƒ#FRMT_DD,D0Šconstantsattheendofdrivercode.,‰MOVE.BƒD0,N4(A2)ŒPutitintotheECAblock.‰ENDI ‰CMP.B„#2,D2 '‰IFTHEN’Executefordrivetype2:)‰LEA†FORMATD(PC),A0‡HarddiskusingECC-9‰MOVE.Lƒ(A0),N4(A2)ŠGetthefieldsfromthelinkANDfrom8‰MOVE.Lƒ#FRMT_HD,D0Šconstantsattheendofdrivercode.,‰MOVE.BƒD0,N4(A2)ŒPutitintotheECAblock.‰ENDI PAGE‰CMP.B„#3,D2 '‰IFTHEN’Executefordrivetype3:)‰LEA†FORMATD(PC),A0‡HarddiskusingCRC-9‰MOVE.Lƒ(A0),N4(A2)ŠGetthefieldsfromthelinkANDfrom8‰MOVE.Lƒ#FRMT_HD,D0Šconstantsattheendofdrivercode.,‰MOVE.BƒD0,N4(A2)ŒPutitintotheECAblock.‰ENDI ‰CMP.B„#4,D2 '‰IFTHEN’Executefordrivetype4:4‰LEA†FORMATS(PC),A0‡Single-density5.25‚floppydisk.9‰MOVE.Lƒ(A0),N4(A2)ŠGetthefieldsfromthelinkANDfrom8‰MOVE.Lƒ#FRMT_SD,D0Šconstantsattheendofdrivercode.,‰MOVE.BƒD0,N4(A2)ŒPutitintotheECAblock.‰ENDI ‰CMP.B„#5,D2 '‰IFTHEN’Executefordrivetype5:4‰LEA†FORMATD(PC),A0‡Double-density5.25‚floppydisk.9‰MOVE.Lƒ(A0),N4(A2)ŠGetthefieldsfromthelinkANDfrom8‰MOVE.Lƒ#FRMT_DD,D0Šconstantsattheendofdrivercode.,‰MOVE.BƒD0,N4(A2)ŒPutitintotheECAblock.‰ENDI SPC 2*F*‚Nowwegettoselecttheworkwe'regoingtodobasedonthetypeofF*‚command.‚Mostoftheworkisgoingtobeforformatcommandsbecause(*‚ofthebufferwe'rerequiredtobuild.*7‰CMP.Bƒ#FMTFUNC,IOFUNCT(A1)‚TesttheI/Ofunctioncode.&‰IF†THENIfNOTaformatcommand,,ŠMOVE.LD4,D0‘Getthelogicalsectornumber.'ŠBSR„LSN2CHSConverttoCYL.HEAD.SECTOR/ŠBSR„CHS2BUFFillthebufferfieldsintheECA. ‰ELSE 3‰CMP.Wƒ#IOPTRK,IOOPTS(A1)„Ifformattrack-by-track,‰IF†THEN*@ŠMOVE.L#0,IOSCTCNT(A1)‡CleartheIOSCTCNTfieldindriveblock.‰ENDI *‰CMP.Wƒ#IOPDSK,IOOPTS(A1)„Ifformatdrive,6‰IF†THENPutthetotalnumbersectorsinIOSCTCNT(ŠMOVE.LCONFGBLK+IOSRSZ(A1),IOSCTCNT(A1)‰ENDI PAGE2‰CMP.Wƒ#IOPBAD,IOOPTS(A1)„Ifformatsectorasbad, ‰IF†THEN*?*ˆThealternatesectorscommandonlyworksfortherigiddisks,>*ˆsowewillcheckhereifwehavearigiddiskandabortwith*ˆanerrormessageifnot.*"‰MOVEQB„ISTAIF,D1•Ifthisisnota/‰MOVE.W„CONFGBLK+IOSATW(A1),D0ˆrigiddis k,then'‰BTSTW…#IOARDISC,D0’abortwithanerror‰BEQ.L…CMDEXIT2–message. *3*ˆRecallthatthealternatesectornumberisinD6.*5‰MOVE.L„CONFGBLK+IOSRSZ(A1),D0ˆgoesbeyondtheendof&‰MOVEQB„ISTARR,D1•thedisk,thenabort#‰SUB.L…D6,D0™withanerrormessage.‰BLS.L…CMDEXIT2*@*ˆConverttheVersadosrecordnumber‚inD6intoalogicalsector5*ˆnumberinD3,thenmoveintoIOALTSECandIOBUFPTR.*/‰MOVE.W„SCTPVREC(A1),D0…SetD3<---D6*SCTPVREC/‰MOVEQ.Lƒ#0,D3bysuccessiveadds,sinceIOSALT‰MOVEQB„ISTARR,D1#‰REPEAT˜ismaybemorethan16bits.-ADD.LƒD6,D3Abortifresultexceeds32bits.BCS.LƒCMDEXIT2 SUBQ.W‚#1,D0 ‰UNTIL.S‚,‰MOVE.L„D3,IOALTSEC(A1)…GetitintoIOALTSEC>‰MOVE.L„D3,IOBUFPTR(A1)…AlsogetitintoIOBUFPTRsotheywill*>*ˆWearegoingtocheckthatthetrackofthealternatesector;*ˆisnotthesameasthetrackofthebadsector.‚Ifitis,7*ˆthecontrollerwouldmakethebadtrackinaccessible,$*ˆandwecertainlydon'twantthat!*B*ˆWhilewearedoingthiserrorchecking,wewillstorethevalues)*ˆforlateruseintheinterruptroutine.*A*ˆThesubroutineLSN2CHStakesalogicalsectornumberinD0,and?*ˆreturnsthecylindernumberinD0.W,theheadnumberinD1.B,1*ˆandthesectornumberwithinthetrackinD2.B.*‰MOVE.L„D6,D0D0<--LSN/‰BSR‡LSN2CHSConversiontocylinder,head,sector0‰MOVE.W„D0,ALTCYL(A1)‡Saveasalternatecylinder.‰MOVE.B„D1,ALTHEAD(A1)†Saveasalternatehead.9‰MOVE.B„#$01,ALTSLC(A1)…Storevalueofsectorlengthcode PAGE*2*ˆRecallthatthesectortobemarkedbadisinD4+*ˆLet'sconvertittocylinder,head,sector.*‰MOVE.L„D4,D0Convertth/‰BSR‡LSN2CHSConversiontocylinder,head,sector:‰MOVE.B„D2,ALTSEC(A1)‡Savebadsectornumberasalternate.?‰MOVE.B„#1,SECTNUM(A2)†Forceformattostartwithfirstsector. 1‰CLR.L…D2’Wedon'tneedtocomparesectornumbers**¦withinthetrack,andweneedtorestore"*¦D2to0becauseitisgoinginto *¦IOSCTCNT$‰CMP.W…ALTCYL(A1),D0‡Samecylinder? ‰IFƒTHENIfnot,noproblem7‰CMP.B…ALTHEAD(A1),D1†Samecylinderandsameheadmeans#*¦sametrack,andthisisanerror.‰IFƒƒTHEN.S“MOVE.B„#ISTAIF,D1 “BRA‡CMDEXIT2‰ENDI‰ENDI (‰ELSEšWe'reformattingbutnoneareBAD. :‰MOVE.Bƒ#0,ALTSEC(A1)ˆSetthisfieldtoindicatenoneBAD.4‰MOVE.LƒD4,D0GettheLSNintothecorrectregister.1‰BSR†LSN2CHSŽConvertLSNtocylinder,head,sector. ‰ENDI 6‰TST.L„FORMBUFF(A1)‰Seeifwealreadyhaveabuffer... ‰IF‚THEN )‰MOVE.Lƒ#FORMSIZE,A0‰Askforformatsize./‰MOVE.Lƒ#4,D0ServicerequestcodeforPAGEALOC7‰MOVEM.L‚A1/A2,-(SP)ŠSave‚A1orthistypeofexeccall.‰BSR†EXECREQ ‰MOVEM.L‚(SP)+,A1/A2ŠRestoreA1.=‰MOVE.LƒA0,FORMBUFF(A1)†SaveaddressofformatbufferinCCB. ‰ENDI *‰BSR†BLDBUFFŽDothisforallformattypes. ‰ENDI PAGE*!*–COMPLETETHEECACOMMANDFIELDS*?*ˆ+-----------------------------+-----------------------------+$*‚$0ƒ|ˆCommandCode‰|‰MainStatus‰|?*ˆ+-----------------------------+-----------------------------+*‚$2ƒ|•ExtendedStatus—|?*ˆ+-----------------------------+-----------------------------+>*‚$4ƒ|‚MaximumNumberofRetries‚|‚ActualNumberofRetriesƒ|?*ˆ+-----------------------------+-----------------------------+$*‚$6ƒ|‰DMATypeŒ|‡CommandOptions‡|?*ˆ+-----------------------------+-----------------------------+* ***¤COMMANDCODEetc..‰MOVE.Lƒ#0,CMDCODE(A2)‡Clearthestatusbytes./‰MOVE.BƒIOFUNCT(A1),D0‡D0<--I/Ofunctioncode‰EXT.W„D0“*B‰MOVE.BƒOPTBL(PC,D0),CMDCODE(A2)UsetabletosetcodeintheECA. ***¤RETRIESANDCOMMANDOPTIONS6‰MOVE.Lƒ#0,MAXRETRY(A2)†Clearretryandoptionsbytes.2‰BTSTW„#IOPRTYB,IOOPTS(A1)‚Testretryoptionsbit.‰IFTHEN’Ifcleared,C‰MOVE.Bƒ#RETRY,MAXRETRY(A2)‚SetthemaximumretrycountintheECA.@‰MOVE.Bƒ#OPT,CMDOPT(A2)†Setcommandoptionforerrorcorrection. ‰ELSEšIfset, ééB‰MOVE.Bƒ#MINTRY,MAXRETRY(A2)keepoptions=0butsetretries=1.‰ENDI ***¤DMATYPE5‰MOVE.Bƒ#DMA,DMATYPE(A2)…SettheDMAtypeintheECA. ‰MOVE.LƒIOBUFTCB(A1),A0:‰ADD.B„#1,TCBIOCNT(A0)ˆIncrementtheTCBIOCNTfieldofthe&*¦TCBthatcontrolsthetaskthatowns)*¦theI/Obuffer(ortheIOCBinthecase%*¦ofaformatcommandoraconfigure-(*¦floppycommand).‚TheTCBIOCNTfieldof%*¦atask'sTCBindicateshowmanyI/O!*¦request(s)thetaskhaspending%*¦completionunderinterruptcontrol. 3‰MOVE.WƒSR,-(SP)SavethevalueoftheSR,andthenééééé6‰MOVE.WƒCCBISR(A5),SRˆinhibitinterruptsattheVME320*¦channel'sinterruptlevel. PAGE6‰LEA†IOQCNT(A5),A0ŠPutthepointertothedrive'sarea2‰MOVE.Wƒ(A0),D2ŽoftheCCBintothenextavailable;EQ570„EQU†IOQUEUE-IOQCNT‡queueentry,andadvancethequeue?‰MOVE.LƒA1,EQ570(A0,D2.W)„pointer.Wecanneveraccumulatemore3‰ADD.W„#4,(A0)Žthanonequeueentryforeachdrive. -‰TST.W„D2•Ifthequeuewasn'temptybeforewe2‰BNE.S„RW420madethelastestentry,theinterrupt$*¦handlerisalreadyactiveandwill)*¦eventuallycompletetheI/Otransaction&*¦thatwe'vejustspecified.‚Otherwise#*¦weneedtoactivatetheinterrupt *¦handler. 8‰LEA†PROCQUE(PC),A0‰Setuptheco-routineswitchpointer>‰MOVE.LƒA0,INTSWTCH(A5)†totelltheinterrupthandlertostart<‰MOVE.LƒCCBCHB(A5),A0ˆprocessinganewI/Oqueueentry.‚Then3‰BSR†INTLOOPŽpointA0totheVME320'smemory-mapped"*¦I/Oarea,andactivateinterrupt%*¦processingbycallingtheinterrupt#*¦handleronceasasubroutine.‚The%*¦machine'sinterruptlevelisatthe)*¦samelevelthatwouldbepresentduring%*¦anactualinterruptfromtheVME320(*¦channel,sotheinterrupthandlerwill*¦performcorrectly. :RW420„MOVE.Wƒ(SP)+,SRRestoretheSR,andtransfercontrol4‰BRA†CMDEXIT3tothecommandprocessor'scommonexit *¦routine.‚Wedon'tqueueanI/O&*¦completioneventyetbecausetheI/O%*¦transactionwillbecompletedlater*¦underinterruptcontrol. O****************************************************************** ***************ˆVME320COMMANDCODETABLE*B*ˆThistablecontainstheVME320definedcommandcodesfortheI/O!*ˆoperationscurrentlysupported.*O******************************************************************************* *‰DC.B…$06’Writecommand:‚IOFUNCTequals-1/OPTBL„DC.B…$07’Formatcommand:IOFUNCTequals‚0*‰DC.B…$00’Configure-seek:IOFUNCTequals‚1(‰DC.B…$05’Readcommand:ƒIOFUNCTequals‚2‰DS.W†0“Endoftable PAGEO********************************************************************************7*ˆSUBROUTINESUSEDBYTHECOMMANDANDINTERRUPTHANDLER*O******************************************************************************* O********************************************************************************9*ˆCONVERTTHEPHYSICALSTARTINGSECTORNUMBERONTHEDISK*B*ˆThisroutineconvertsthePhysicalsectornumbercontainedinD0>*ˆtothecylindernumber,headnumberandsectornumberfields/*ˆrequiredfortheECApacket,andstoresthem.*:*ˆEntry:„A1=Pointertodrive'svariableblockintheCCB#*’A2=Pointertodrive'sECAblock.*’D0=Physicalsectornumbertobeconverted.*!*ˆRegisterusage:…01234567 *™D‚RRR*™A„PP**ˆExit:…D0.W=Cylindernumber*’D1.B=Headnumber5*’D2.B=Sectornumberwithintrack(startingwith1)*8*ˆExitsto:‚CommandHandlerorInterruptHandlerviaRTS***‘PSN=*ˆ---------------------------ƒ=Cylindernumber+Remainder1*ˆSectorsperTrack*#Heads* *‹Remainder10*ˆ------------------Œ=Headnumber+Remainder2*ˆSectorsperTrack*/*ˆRemainder2“=Sectornumber(countingfrom0)*B*ˆNOTE:„Thisdriversometimesreferstothephysicalsectornumber9*‘asthelogicalsectornumber-theyarethesamething.*O******************************************************************************* SPC 2*+*’COMPLETESECTORADDRESSFIELDSINTHEECA*?*ˆ+-----------------------------------------------------------+*‚$10ƒ|–CylinderNumber–|?*ˆ+-----------------------------+-----------------------------+0*‚$12ƒ|„HeadorSurfaceNumberƒ|‡SectorNumber‰|?*ˆ+-----------------------------+-----------------------------+* PAGE LSN2CHS ‰CLR.L„D1 ‰CLR.L„D2 -‰MOVE.WƒSURF(A1),D1D1<--NumberofsurfacesA‰MOVE.BƒCONFGBLK+IOSSPT(A1),D2„D2<--Numberofsectorspertrack3‰MULU…D2,D1D1<---Numberofsurfaces*sect/track$‰DIVU…D1,D0D0.W<--Cylindernumber ‰MOVE.LƒD0,D1/‰LSR.L„#8,D1Shiftremainder1fornextdivide.!‰LSR.L„#8,D1D1.W<--Remainder1 ‰DIVU…D2,D1D1.W<--Headnumber ‰MOVE.LƒD1,D2-‰SWAP…D2“D2.W‚<---Sectornumberinthetrack4‰ADDQ.Lƒ#1,D2VME320countssectorsstartingatone. ;‰MOVE.WƒD0,CYLNUM(A2)ˆPutcylindernumberintheECAblock.8‰MOVE.BƒD1,HEADNUM(A2)‡PutheadnumberintheECAblock.:‰MOVE.BƒD2,SECTNUM(A2)‡PutsectornumberintheECAblock. ‰RTS PAGEO*********************************************************************************ˆCHSTOBUFFERADDRESS*8*ˆThisroutinefillsthebufferfieldsintheECAblock.-*ˆItusesthefieldsoftheI/OpacketstoredA*ˆearliertomakecalculationsabouttransferlengths.‚Itupdates;*ˆfieldsintheI/Opacketthatareusedlatertodetermine@*ˆifthecommandhasbeencompleted.‚Thisroutineiscalledfrom1*ˆboththecommandhandlerandinterrupthandler.*:*ˆEntry:„A1=Pointertodrive'svariableblockintheCCB#*’A2=Pointertodrive'sECAblock*’D0.W=Cylindernumber}3*’D1.B=Headnumber…}-definingstartingsector#*’D2.B=Sectornumberƒ}*!*ˆRegisterusage:…01234567 *™D‚****™A„PP*D*ˆExit:(1)SetsthebufferfieldsinECAblockforread/writeonly.;*Ž(2)ModifiesN4,SLCandDRVTYPEfieldsintheECApacket7*’fortrack0accessesonadouble-densityfloppydisk.<*Ž(3)UpdatestheI/Opackettodeterminecommandcompletion#*’forreadandwritecommandsonly.**ˆExitsto:CallerviaRTS* O******************************************************************************* SPC 2* *•COMPLETETHEECABUFFERFIELDS*?*ˆ+-----------------------------+-----------------------------+%*‚$8ƒ|“BufferAddress(upperword)|?*ˆ+-----------------------------+-----------------------------+%*‚$Aƒ|“BufferAddress(lowerword)|?*ˆ+-----------------------------+-----------------------------+!*‚$Cƒ|“BufferLengthRequested‘|?*ˆ+-----------------------------+-----------------------------+,*‚$Eƒ|ŽActualNumberofBytesTransferred‹|?*ˆ+-----------------------------+-----------------------------+* PAGE CHS2BUF;‰MOVE.LƒIOBUFLEN(A1),D0†D0<--numberofbytestotransfer.6‰IFTHEN’Bufferlengthiszeroforformat&seek. (‰CLR.L„D1“Ifdouble-densityfloppy,then=‰MOVE.BƒHALFSCTS(A1),D1†D1<--sectortransferacrosstrack0 ‰IFTHEN0ŠMULU…#128,D1D1<--#bytestotransfertrack08ŠMOVE.Bƒ#0,SLC(A2)ŠChangesectorlengthcodeintheECA.ŠMOVE.Lƒ#FRMT_SD,D2‰*1ŠMOVE.BƒD2,N4(A2)‹ChangeformatfieldintheECA.?ŠBTST.Bƒ#0,DRVTYPE(A2)†Makingsuredrivetypeindicatesdouble-ŠIFTHEN‘*>ŠSUB.B„#1,DRVTYPE(A2)†ChangedrivetypecodetosingledensityŠENDI-ŠSUB.L„D1,D0D0<--#bytestotransfernext. ‰ELSE4ŠMOVE.Lƒ#MAXB,D1ŒD1<--maxnumberofbytestoxfer./ŠCMP.L„D1,D0Comparetonumberbytesrequested.3ŠIFTHEN‘Branchifthetransferiswithinmax.-ŠSUB.L„D1,D0Subtractmaximumfromrequested.&ŠELSE™D0<--#bytestotransfernext.-ŠMOVE.LƒD0,D1D1<--#bytestotransfernow./ŠMOVEQ.L‚#0,D0D0<--#bytestotransfernext.ŠENDI‰ENDI PAGE*.*‚Copythebufferlength(inbytes)totheECA'*ˆD1=NumberofbytestotransferNOW.(*ˆD0=NumberofbytestotransferNEXT.*8‰MOVE.WƒD1,BUFLEN(A2)ˆCopythebytestotransfertoECA. &‰MOVE.LƒA0,-(SP)SaveA0onthestack./‰MOVE.LƒIOBUFPTR(A1),A0†Getthebufferaddress.+‰GO_OFF_BDA0’Adjustifthereisanoffset.:‰MOVE.LƒA0,BUFADDR(A2)‡CopythebufferaddresstotheECA.‰MOVE.Lƒ(SP)+,A0RestoreA0.*$*ƒHousekeepinginthedriveblock...*5‰ADD.L„D1,IOBUFPTR(A1)†<--1stbytetotransfernext.5‰MOVE.LƒD0,IOBUFLEN(A1)†<--#bytestotransfernext. ‰DIVU…BPS(A1),D17‰ADD.L„D1,IOSECTOR(A1)†<--1stsectortotransfernext.‰DIVU…BPS(A1),D07‰MOVE.LƒD0,IOSCTCNT(A1)†<--#sectorstotransfernext. ‰TST.B„HALFSCTS(A1) ‰IFTHEN ŠCLR.L‚D0ŠMOVE.BCONFGBLK+IOSSPT(A1),D08ŠMOVE.LD0,IOSECTOR(A1)‡<--1stsectortotransfernext.,‰ENDIš(double-densityfloppies/track0only) ‰ENDI ‰RTS *A*„NOTESONMULTIPLETRANSFERS:‚MulitpleblocktransferscanoccurN*‚when:(1)thedatatransfercrossesthetrack0boundaryofadouble-densityL*‚floppydiskand(2)thedatatransferislargerthanthemaximumnumberof*‚bytesallowedbytheVME320.* PAGEO*********************************************************************************ˆBUILDFORMATBUFFERROUTINE*A*ˆThisroutinebuildstheformatbufferfortheVME320controllerA*ˆboard.‚ItusesfieldsfromtheECApacketforitscomputations.?*ˆItimplementsinterleavingandspiraloffset.Thisroutineis=*ˆcalledfromboththeinterrupthandlerandcommandhandler.*:*ˆEntry:„A1=Pointertodrive'svariableblockintheCCB#*’A2=Pointertodrive'sECAblock*!*ˆRegisterusage:…01234567 *™D‚****™A„PP*C*ˆExit:(1)SetsthebufferfieldsintheECAblockforformatcmd.:*Ž(2)Buildstheformatbufferforonetrack,implementing.*’'formatsectorasbad'optionfromVERSAdos.**ˆExitsto:CallerviaRTS*O******************************************************************************* ?BLDBUFF‚MOVEM.L‚D4/A0/A3,-(SP)‡Saveworkingregistersonstack. ‰CLR.L„D2%‰MOVE.WƒSPT(A1),D2‹Sectorspertrack. 0‰CMP.W„#IOPDSK,IOOPTS(A1)ƒTestthecommandtype. ‰IFTHEN’Housekeeping...;‰SUB.LƒD2,IOSCTCNT(A1)‡Decrementsectorcountformat-drive.;‰ADD.LƒD2,IOSECTOR(A1)‡Incrementstartsectorformat-drive .‰ENDI :‰TST.B„HALFSCTS(A1)‰Executefortrack0onDDfloppyonly: ,‰IF‡THENŒResetthesefieldsintheECA::‰MOVE.Bƒ#0,SLC(A2)‹Changesectorlengthcodeto128bytes.‰MOVE.Lƒ#FRMT_SD,D0Š*6‰MOVE.BƒD0,N4(A2)ŒChangeN4toreflectsingledensity.0‰BTST.Bƒ#0,DRVTYPE(A2)‡Changedrivetypecode...1‰IF‡THENŒMakesureitindicatesDDbeforewe‰SUB.B„#1,DRVTYPE(A2)‡subtract.‰ENDI‰ENDI :‰LEA†SECTBUFF(A5),A0†Getpointertosectornumbersbuffer.,‰MOVE.LƒA0,A3A0<--Sectornumberbuffer#1 PAGEL****************************************************************************>*ˆBUILDSTRINGOFSECTORNUMBERSUSINGTHEINTERLEAVEFACTORˆ*L*****************************************************************************E*‚A0=Pointertosectornumberbuffer#1usedforinterleavefactors3*‚A1=Pointertodrive'svariableblockintheCCB#*‚A2=Pointertodrive'sECAblock*‚D0=Scratch*‚D1=Scratch*‚D2=Sectorspertrack,*‚D4=Scratch(willholdinterleavefactor) ‰CLR.L„D4E‰MOVE.BƒCONFGBLK+IOSILV(A1),D4Interleavefactorfromconfigureblock$‰IF‡THENŒIfNOTzero,itsokay.4‰MOVEQ.L‚#1,D4Makethefactorofzeroequaltoone.‰ENDI 4*ˆCMP.W„#IOPBAD,IOOPTS(A1)ƒFormatcommandoptions...'*ˆIF‡THENŒIfformatsectorasbad,,*ˆCMP.B„#1,D4Andinterleavingisspecified,*ˆIF‡THEN<*ˆMOVE.Bƒ#1,ALTSEC(A1)ˆForceentiretracktobeformatedBAD*ˆENDI*ˆENDI &‰MOVEQ.L‚#1,D0Startingsectornumber.+‰BRA.S„RW_INTBŽBranchtoentryinsideloop. +RW_INTA‚MOVE.BƒD1,(A0)+Copysectornumber.#‰ADD.L„D4,D1Addinterleavefactor.8‰CMP.W„SPT(A1),D1‹Havewegottothelastsectornumber?&‰BLE.S„RW_INTCŽBranchiflastorless./‰ADDQ.Lƒ#1,D0Incrementstartingsectornumber.* Enter here.RW_INTB‚MOVE.LƒD0,D1Copytoworkingregister.RW_INTC‚DBRA…D2,RW_INTA PAGEL****************************************************************************:*ˆBUILDSTRINGOFSECTORNUMBERSUSINGTHESPRIALOFFSETŒ*L*****************************************************************************I*‚A0=Pointertosectornumberbuffer#2usedtoimplementspiraloffset3*‚A1=Pointertodrive'svariableblockintheCCB#*‚A2=Pointertodrive'sECAblockB*‚A3=Pointertostartofsectornumberbuffer#1(savedearlier)*‚D0=Scratch*‚D1=Scratch*‚D2=Scratch(*‚D4=Scratch(willholdspiraloffset) ‰CLR.L„D4:‰MOVE.BƒCONFGBLK+IOSSOF(A1),D4„D4<--‚Spiraloffsetvalue.'‰IF‡THENŒBranchifaroundifnone. 4*ˆCMP.W„#IOPBAD,IOOPTS(A1)ƒFormatcommandoptions...'*ˆIF‡THENŒIfformatsectorasbad,<*ˆMOVE.Bƒ#1,ALTSEC(A1)ˆForceentiretracktobeformatedBAD*ˆENDI :‰MOVE.WƒSPT(A1),D2‹Getthenumberofsectorsinthetrack.&‰SUBQ.Lƒ#1,D2D2<--DBxxloopcounter ARW_SOFƒMOVE.Bƒ(A3)+,(A0)+ŠCopythesectornumbersw/interleaving(‰DBRA…D2,RW_SOFŒtothebufferfollowing. <‰MOVE.BƒHEADNUM(A2),D0‡D0<--surfacenumberfromECAblock.+‰MULU…D0,D4SpiralOffset*Surfacenumber.%‰MOVE.WƒSPT(A1),D2‹Sectorspertrack.)‰SUB.L„D4,D2Offsetduetospiraloffset.2‰LEA†SECTBUFF(A5),A3†Pointertointerleavebuffer.-‰ADDA.LƒD2,A3A3<--stringofsectornumbers ‰ENDI PAGE2***************************************************ˆCOMPLETETHEFORMATBUFFERŽ*2***************************************************3*‚A0=Scratch‚(willholdpointertoformatbuffer)3*‚A1=Pointertodrive'svariableblockintheCCB#*‚A2=Pointertodrive'sECAblockM*‚A3=Pointertostringofsectornumbersw/interleavingandspiraloffsets*‚D0=Scratch*‚D1=Scratch*‚D2=Scratch*<‰MOVE.LƒFORMBUFF(A1),A0†A0<--Pointertotheformatbuffer.;‰MOVE.BƒALTSEC(A1),D0ˆD0<--Badsectorinalternatetrack. *¦NOTE:ALTSEChasbeensetto0$*¦ifthiswasnotaformatsectoras*¦badcommand. ‰CLR.L„D2:‰MOVE.WƒSPT(A1),D2‹Getthenumberofsectorsinthetrack.&‰SUBQ.Lƒ#1,D2D2<--DBxxloopcounter THENŒBuildthebufferforGOODsectors... 9‰BTST.Bƒ#1,DRVTYPE(A2)‡Drivetypedefines#bytes/sector:5‰BEQ.S„FMT_FLOP5-bytesforharddisks/4-bytesfloppy=‰MOVE.BƒCYLNUM(A2),(A0)+…CopytheMSBofthecylindernumber.GFMT_FLOPMOVE.BƒCYLNUM+1(A2),(A0)+ƒCopytheLSBofthecylindernumber.+‰MOVE.BƒHEADNUM(A2),(A0)+„Headnumber-all'‰MOVE.Bƒ(A3)+,(A0)+ŠSectornumber-all.‰MOVE.BƒSLC(A2),(A0)+ˆSectorlengthcode-all )‰ELSEšBuildthebufferforBADsectors... '‰MOVEQ.L‚#2,D1D1<--DBxxloopcounterHBAD_SEC‚MOVE.BƒCYLNUM(A2),(A0)+…CopytheMSBoftheBadcylindernumber.C‰MOVE.BƒCYLNUM+1(A2),(A0)+ƒCopytheLSBoftheBadcylindernumber.)‰MOVE.BƒHEADNUM(A2),(A0)+„Badheadnumber$‰MOVE.Bƒ(A3),(A0)+‹Badsectornumber;‰MOVE.Bƒ#$FF,(A0)+‹ForceSLCto$FFtoindicateBADsector.7‰MOVE.BƒALTCYL(A1),(A0)+…AlternatecylindernumberMSB.9‰MOVE.BƒALTCYL+1(A1),(A0)+ƒAlternatecylindernumberLSB./‰MOVE.BƒALTHEAD(A1),(A0)+„Alternateheadnumber*‰MOVE.Bƒ(A3),(A0)+‹Alternatesectornumber5‰MOVE.BƒALTSLC(A1),(A0)+…Alternatesectorlengthcode+‰MOVE.Bƒ#72,(A0)+ŒPostIDgap(fixedvalue)8‰DBRA…D1,BAD_SEC‹Repeattoget2IDheaderswrittenout. 2‰ADD.L„#1,A3IncrementA3topointtonextsector.‰ENDI 5‰DBRA…D2,FMT_LOOPŠCompletethebuffer-daterequired *¦foreverysectorinthetrack. PAGE*<*‚Thebufferisbuilt-FillbufferfieldsintheECAblock.*8‰MOVE.LƒFORMBUFF(A1),D2†D2<--1stbyteinformatbuffer0‰MOVE.LƒA0,D1D1<--1stbytepastformatbuffer-‰SUB.L„D2,D1D1=lengthoftheformatbuffer-‰MOVE.LƒD2,A0D2=startoftheformatbuffer/‰GO_OFF_BDA0’Adjustfordual-portramaddress. <‰MOVE.LƒA0,BUFADDR(A2)‡PuttheformatbufferaddressinECA.=‰MOVE.WƒD1,BUFLEN(A2)ˆPutthelengthofformatbufferinECA.*>*‚Replacethesectorspertrackfieldforbadsectorhandling.*‰CLR.L„D2“*4‰MOVE.WƒSPT(A1),D2‹D2<--currentsectorspertrack.=‰MOVE.BƒALTSEC(A1),D0ˆTestflagindicatingbadsectornumber.3‰IF‡THENŒIfflagisthenweabadsector.<‰ADD.B„#2,NUMSPT(A2)ˆAddtothenumberofsectorspertrack.‰ELSE<‰MOVE.BƒD2,NUMSPT(A2)ˆRestoresectorspertrackifallgood.‰ENDI*I*‚Nowthisisinteresting.‚InordertoformatasectorasbadandspecifyM*‚analternate,thenumberofsectorspertrackmustbeadjustedtoequaltheG*‚numberof'CYL-HEAD-SECTOR#...'datasequencesintheformatbuffer.J*‚Whenallthesectorsaregood,thenthisfieldexactlyequalsthenumberI*‚ofsectorsinthetrack.‚Whenanybadsectorsarespecified,thisfieldF*‚isincreasedby3timesthenumberofbadsectorstoaccountfortheF*‚threeIDheadersspecifyingthealternatewrittentothebadsector.*+‰MOVEM.L‚(SP)+,D4/A0/A3‡Restorefromstack.‰RTS PAGEO*********************************************************************************ˆMEMORYRETURN*<*ˆThisroutineiscalledbytheinterrupthandlerforformat:*ˆcommands.‚It'spurposeistoreturntheglobalmemoryit<*ˆrequestedfortheformatbufferwhichisnolongerneeded.*:*ˆEntry:„A1=Pointertodrive'svariableblockintheCCB*’A5=AddressofourCCB.*!*ˆRegisterusage:…01234567*™D‚***™A‚P**ˆExit:…Tocallerifnoerrors*’Tokilleriferror*O******************************************************************************* MEMRTN)‰MOVE.Lƒ#FORMSIZE,D1‰Askforformatsize./‰MOVE.Lƒ#5,D0ServicerequestcodeforPAGEFREE%‰MOVE.LƒFORMBUFF(A1),A0†Startaddress8‰MOVE.Lƒ#0,FORMBUFF(A1)†Cleartheformatbufferpointer.;‰MOVEM.L‚A1/A2,-(SP)ŠMustsaveA1/A2forthistypeofcall.‰BSR†EXECREQ "‰MOVEM.L‚(SP)+,A1/A2ŠRestoreA1/A2!‰MOVE.LƒCCBCHB(A5),A0ˆRestoreA0.‰RTS PAGEO********************************************************************************(*ˆLOGICAL-TO-PHYSICALADDRESSCONVERSION*F*ˆGivenaphysicalTCBaddressandthelogicaladdressandlengthofaE*ˆmemorya rea,subroutine‚LOGPHYcomputesthephysicaladdressoftheE*ˆmemoryarea.‚ItalsocheckstomakesurethatthegivenmemoryareaE*ˆreallybelongstothetask‚thatiscontrolledbythespecifiedTCB.*@*ˆThesubroutine‚has‚twoentrypoints:‚LOGPHY‚isused‚when‚we'reF*ˆdealingwithataskthatownstheTCBandLOGPHY1isusedwhenwe're)*ˆdealingwithataskthatownstheIOCB.*<*ˆEntry:„A5=PhysicaladdressofCCB(entry@LOGPHY1only);*’D6=Logicaladdressofthefirstwordofthememoryarea)*’D5=Lengthinbytesofthememoryarea*!*ˆRegisterusage:…01234567*™D‚PP‡PR *™A‚*P‡P*B*ˆExit:…D6=physicaladdressofthefirstwordofthememoryarea *’Returntothecallingroutine.*O******************************************************************************* =LOGPHY1‚MOVE.LƒCCBTASKA(A5),A0ˆSetA0tocontainthephysical&*¦addressoftheTCBthatcontrolsthe)*¦taskthatownstheIOCBforthecommand(*¦thatiscurrentlybeingprocessed.‚The'*¦memoryareaweseekallegedlybelongs!*¦tothetaskthatownstheIOCB. FLOGPHYƒMOVEM.L‚D0-D5/D7/A0,-(SP)†Savetheworkingregistersbypushing'*¦themontothestack.‚Wedon'tuseall&*¦oftheseregistersdirectly,butthe)*¦T0LOGPHYexecutiveroutinedestroysthe*¦onesthatwedon'tuse. 3‰MOVE.WƒD6,CCR‘Checktoseeifthespecifiedmemory/‰BCS.S„LOG10areabeginsatanoddaddress,and&*¦abortifitdoes.‚Wewantthememory#*¦areatostartonawordboundary.)*¦Noticethatwecheckforanoddaddress'*¦bycopyingbit0oftheaddressvalue*¦intotheCbitoftheCCR. /‰TST.L„D5•Abortprocessingifthelengthofthe3‰BEQ.S„LOG10specifiedmemoryareaiszero.‚Azero-$*¦lengthmemoryareaismeaningless. :‰MOVE.LƒTCBTST(A0),A0ŠGetthephysicaladdressoftheTask:‰MOVE.Lƒ#T0LOGPHY,D0‰SegmentTableforthegiventaskinto/‰TRAP…#EXECA0,anduseanexecutiverequestto'*¦performtheconversionfromalogical *¦addresstoaphysicaladdress. PAGE 2‰BRA.S„LOG20’Controlreturnsfromtheexecutiveto'*¦thispointiftheconversionwasgood'*¦andthespecifiedmemoryarearesides'*¦entirelywithinamemorysegmentthat$*¦belongstothespecifiedtask.‚The(*¦physicaladdressofthememoryareais(*¦inD6,sowe'realmostreadytoreturn$*¦controltotheroutinethatcalled*¦subroutineLOGPHY. *‰NOPControlreturnsfromtheexecutiveto)*¦thispointifthespecifiedmemoryarea#*¦ispartiallyinsideandpartially'*¦outsideamemorysegmentthatbelongs(*¦tothespecifiedtask.‚Inthiscasewe*¦wanttoreportanerror. =LOG10„MOVEQBƒISTAADD,D1Controlreturnsfromtheexecutiveto4‰BRA†CMDEXIT2thispointif(1)thespecifiedmemory'*¦areaiscompletelyoutsideanymemory'*¦segmentthatbelongstothespecified'*¦taskor(2)thespecifiedmemoryarea!*¦isinamemory-mappedI/Oarea. 8BADBUFADEQU†LOG10’Controlalsocomestothispointfrom(*¦severalotherplaces,includingplaces(*¦outsidesubroutineLOGPHY.‚Weusethis$*¦codetoreportanykindofbuffer-#*¦addresserrorthatwecandetect. #*¨Wequeueaneventtotheattached(*¦tasktoindicatethatwehavereceived$*¦abadlogicaladdress,andthenwe'*¦abortprocessingforthecommandthat*¦iscurrentlybeingprocessed. ELOG20„MOVEM.L‚(SP)+,D0-D5/D7/A0†Controlreachesthispointwhenwe've*‰RTS›madeasuccessfuladdressconversion.&*¦Werestoretheworkingregistersand(*¦returncontroltothecallingroutine. PAGE O*********************************************************************************ˆQUEUEANEVENT*H*ˆSubroutineQEVENTqueuesaneventmessagetothetaskthatisattachedC*ˆtothe‚channel.‚Thereare‚twoentrypoints‚tothesubroutine.‚TheC*ˆQEVENT‚entrypoint‚canbeused‚toqueue‚anevent‚fromthecommandD*ˆprocessor‚tothe‚attachedtask,‚andthe‚QEVENTIentrypointcanbeC*ˆusedto‚queue‚anevent‚fromthe‚interrupthandler‚totheattached@*ˆta sk.ƒIneither‚case,it‚queues‚an‚I/Ocompletion‚event‚tothe*ˆattachedtask.*%*ˆEntry:„A3=PhysicaladdressofDCB*’A4=PhysicaladdressofIOCB*’A5=PhysicaladdressofCCB*$*D1.B=EventstatusandI/Ostatus*!*ˆRegisterusage:…01234567*™D‚*PPPPP *™A‚PPƒPPP*C*ˆExit:…Returnscontroltothecallingroutineforgoodcompletion.&*’InvokesT0KILLERforbadcompletion.*O******************************************************************************* @QEVENTI‚MOVE.Lƒ#T0QEVNTI,D0‹Thisentrypointisusedtoqueuean2‰BRA.S„QEVENTI/OcompletioneventfromtheVME320)*¦interrupthandlertotheattachedtask.$*¦Thereisoneexecutiverequestfor$*¦queuinganeventfromaninterrupt)*¦handler,andthereisanotherexecutive%*¦requestforqueuinganeventfroma"*¦routinethatisnotaninterrupt'*¦handler.‚Herewegettherequestcode'*¦fortheexecutiverequestthatqueues%*¦aneventfromaninterrupthandler. PAGE @QEVENTT‚MOVE.Lƒ#T0QEVNTT,D0‹Thisentrypointisusedtoqueuean&*¦I/OcompletioneventfromtheVME320)*¦commandprocessortotheattachedtask.$*¦Thereisoneexecutiverequestfor$*¦queuinganeventfromaninterrupt)*¦handler,andthereisanotherexecutive%*¦requestforqueuinganeventfroma"*¦routinethatisnotaninterrupt'*¦handler.‚Herewegettherequestcode'*¦fortheexecutiverequestthatqueues(*¦aneventfromaroutinethatisnotan*¦interrupthandler. FQEVENTƒMOVEM.L‚D1-D7/A0-A5,-(SP)†Savetheworkingregistersbypushing'*¦themontothestack.‚Wedon'tuseall&*¦oftheseregistersdirectly,butthe&*¦executiveroutinethatqueuesevents*¦usessomeofthem. 9‰MOVE.BƒD1,IOSSTA(A4)ŠStorethestatuscodeintotheIOCB&*¦whereitcanbeexaminedbythetask#*¦thatoriginallyrequestedtheI/O#*¦transactionwe'vejustcompleted. 6‰MOVEQBƒEVNTCOMP,D2ŒGetthetypecodeforanormalI/O;‰MOVEQBƒEVNTCMSZ,D3ŠcompletioneventintoD2.B,andgetthe#*¦length(inbytes)ofanormalI/O*¦completioneventintoD3.B. 5‰MOVEQBƒEVNTIO,D4ŽGettheeventcodeforanI/Oevent*¦intoD4.B. PAGE 8‰LINK…A0,#-EVNTMXSZŠReserveenoughroomonthestackfor5‰MOVE.LƒA0,A1thelargestpossibleeventmessage,and(*¦setupA1asatemporarystackpointer'*¦forpointingintotheeventareathat#*¦we'vejustreservedonthestack.)*¦We'lluseA1asaworkingregister,and(*¦we'llpreserveA0.‚Weneedtopreserve(*¦A0sowecanrestorethestackpointer%*¦afterwe'refinishedwiththeevent%*¦area.‚Thestackisnoworganizedas *¦follows. *²|‚AvailableStack„|*²|---------------------|*¦SP------->|‚EventArea‰|*²|Š.Š|*²|Š.Š|*²|Š.Š|*²|---------------------|*¦A0,A1--->|‚OldA0Value‡|*²|---------------------|*²|‚WorkingRegisters‚|*²|Š.Š|*²|Š.Š|*²|Š.Š|*²|---------------------| *¨We'regoingtobuildtheevent(*¦messageintheeventareathatwejust&*¦createdonthestack,andthenwe'll!*¦copytheeventmessageintothe'*¦registersforqueuingtotheattached%*¦task.‚Byusingthestackasanarea$*¦forbuildingtheeventmessage,we&*¦assurethatthissubroutineisfully%*¦re-entrant.‚Thissubroutinemustbe$*¦fullyre-entrantbecauseitcanbe(*¦executedfromboththecommandservice$*¦routineandtheinterrupthandler. '*¨Noticethattheapproachwetakehere)*¦willworkproperlyforaneventmessage*¦ofanypossiblelength. &*¨Nowwemuststartbuildingtheevent(*¦message(fromendtobeginning)inthe*¦eventareaofthestack. PAGE 5‰MOVE.BƒD1,-(A1)Storethestatusbyteintotheevent1‰CLR.B„-(A1)area,andclearthenextbyte.‚There'*¦aretwobytesfortheeventstatusin%*¦theeventmessage,butoneofthose'*¦bytesmustalwaysbezero.‚We'vejust(*¦filledtheEVNTSTATfieldoftheevent *¦message. 6‰MOVE.LƒA3,-(A1)StorethephysicaladdressoftheDCB%*¦intotheEVNTDCBfieldoftheevent*¦area. =‰MOVE.BƒCCBKEY(A5),-(A1)‡Copytheke yvaluethatwassupplied'*¦bytheattachedtaskintotheEVNTKEY*¦fieldoftheeventarea. 6‰MOVE.BƒD2,-(A1)StorethetypecodeintotheEVNTTYPE*¦fieldoftheeventarea. ;‰MOVE.LƒCCBSVVC(A5),D5‰Iftheattachedtaskhasn'tsupplied4‰BEQ.S„QUE10aneventserviceaddressforI/Oevents&*¦fromthischannel,omittheEVNTSVAD*¦fieldoftheevent. 1‰ADD.B„#EVNTSVSZ,D3‹Otherwise,adjustD3.B,which6‰MOVE.LƒD5,-(A1)containstheeventlength,toaccount òCû67;37#7+634;5C<K9S4[:c6k:8‰MOVEQBƒEVNTIOSA,D4ŠfortheaddedlengthoftheEVNTSVAD)*¦field,andputtheserviceaddressinto'*¦theEVNTSVADfieldoftheeventarea.(*¦Also,changetheeventcodeinD4.Bto)*¦indicatethatwehaveanI/Oeventwith*¦aserviceaddressincluded. 3QUE10„MOVE.BƒD4,-(A1)Storetheeventcodeintothe#*¦EVNTCODEfieldoftheeventarea. 5‰CMP.B„CCBASQL(A5),D3‰Iftheeventmessagewe'vejust4‰BLS.S„QUE20constructedintheeventareaislarger:‰MOVE.BƒCCBASQL(A5),D3‡thanthelargesteventtheattached)*¦taskispreparedtoreceive,changethe&*¦eventlengthinD3.Btotruncatethe%*¦eventmessagetothemaximumlength#*¦thatthetaskcanaccommodate.‚In&*¦actualpracticewe'llnevertruncate&*¦anyeventsherebecausetheattached&*¦taskwillbeIOS,whichissetupto(*¦receivethelongesteventmessagethat*¦wecouldeversend. 5QUE20„MOVE.BƒD3,-(A1)Storetheeventlengthintothe$*¦EVNTLENfieldoftheeventareato*¦completetheeventmessage. PAGE 9‰MOVEM.L‚(A1),D2-D6Nowgettheeventfromtheeventarea'*¦intotheregisters.‚Wepickupenough)*¦registervaluesheretoaccommodatethe'*¦longestpossibleeventbecausethat's'*¦easierthanitwouldbetotrytoget)*¦therightnumberofregistervaluesfor#*¦theeventthatwehappentohave.$*¦We'resafeinaccessingbeyondthe(*¦actualeventareainthestackbecause(*¦weknowthereismemorywherewesaved*¦theworkingregisters. .‰UNLK…A0•Restorethestackpointersincewe're)*¦nowfinishedwiththeeventareaofthe*¦stack. ;‰MOVE.LƒCCBRQSTA(A5),A0ˆGetthephysicaladdressoftheTCB1‰BSR.S„EXECREQŽfortheattachedtaskintoA0,and$*¦performtheexecutiverequestthat#*¦queuestheeventmessagefromthe(*¦registerstotheattachedtask.‚Recall(*¦thatD0containstheexecutiverequest%*¦codefortheexecutiverequestthat'*¦queuestheeventmessageproperlyfor%*¦thecurrentenvironment.‚Subroutine'*¦EXECREQkillstheoperatingsystemif)*¦thesystemisunabletoqueuetheevent*¦forsomeunexpectedreason. =‰MOVEM.L‚(SP)+,D1-D7/A0-A5†Restoretheworkingregisters,and+‰RTS›returncontroltothecallingroutine. PAGE O*********************************************************************************ˆEXECUTIVE-REQUESTSUBROUTINE*E*ˆThesubroutineEXECREQperformsaTrap-0ExecutiveRequestandthenB*ˆkillsthesystemiftheexecutivedoesnotsuccessfullyrespond.*O******************************************************************************* EXECREQ: 0‰TRAP…#EXEC’Performtheactualexecutiverequest(*¦thatwassetupbeforethissubroutine *¦wascalled. *‰RTSControlreturnsfromtheexecutiveto&*¦thispointiftheexecutivesuccess-)*¦fullyperformedtherequestedfunction.'*¦Inthiscasewereturncontroltothe#*¦routinethataskedustomakethe*¦executiverequest. :‰MOVE.Lƒ#T0KILLER,D0‹Controlreturnsfromtheexecutiveto2‰TRAP…#EXECthispointiftheexecutivewasunable#*¦toperformtherequestedfunction%*¦successfully.‚Thissituationshould'*¦neverariseforanyexecutiverequest&*¦thattheVME320drivermakesthrough)*¦thissubroutine.‚Ifthissituationdoes(*¦arise,wekillthesystemtobringthe"*¦unex pectedproblemforcefullyto&*¦someone'sattentionforanalysisand *¦resolution.‰PAGE‰TTL‡VME320INTERRUPTHANDLER O*******************************************************************************O*******************************************************************************O*********************************************************************************ˆVME320INTERRUPTHANDLER*G*ˆControlcancometotheVME320interrupt‚handlerwhenCMRreceivesanH*ˆinterruptontheinterruptlevelthatisusedbytheVME320controllerF*ˆIfthe‚interruptisaVME320interrupt,theVME320‚interrupthandlerF*ˆsetstheCbitoftheSR,andlowersthe‚interruptmask‚levelbyone*ˆleveluponreturn.*?*ˆEntry:„A1=PhysicaladdressoftheVME320interrupthandler.#*’A5=PhysicaladdressoftheCCB.3*’SR=MaskedattheleveloftheVME320interrupt.*O*******************************************************************************O*******************************************************************************O******************************************************************************* PAGE O********************************************************************************"*ˆVME320INTERRUPTPOLLINGROUTINE*%*ˆEntry:„A5=physicaladdressofCCB*/*ˆRegisterUsage:D0,A0bothsavedbytheexec.*1*ˆFunction:Determineiftheinterruptifforme.*>*ˆExit:…ReturntoCMRviaRTSifitISNOTaVME320interrupt./*’BranchtoINT200ifitISaVME320interrupt.*O******************************************************************************* INTERUPT:7‰MOVE.L„CCBCHB(A5),A0‰Getthememory-mappedI/Oaddress0‰MOVEQ.Lƒ#7,D0oftheVME320andtesttheSOURCE@INT100ƒBTST†D0,SOURCE(A0)‡registertodeterminewhichdrivesent3‰BNE.S…INT200Žtheinterrupt.Ifnoneofthebitsin7‰DBRA†D0,INT100‹SOURCEareset,disclaimtheinterrupt. *¦THEINTERRUPTISNOTFORMECLEAR„EQU‡0<<0‰AND.B…#CLEAR,CCR‰RTS PAGE O********************************************************************************%*ˆVME320INTERRUPTCO-ROUTINELINKAGE*C*ˆControlreachesthispointwhenwe'vesuccessfullyidentifiedthe@*ˆinterruptasaVME320interrupt‚ORƒthisroutineiscalledasa(*ˆsubroutinefromthecommandprocessor.*?*ˆEntry:„A0=PhysicaladdressofVME320Memory-MappedI/Oarea*’A5=PhysicaladdressofCCB*!*ˆRegisterusage:…01234567'*™D‚*####=Savedtouseasworking%*™A‚PRR##Pregistersthroughout.*"*ˆExit:…Jumptoco-routinesegment*O******************************************************************************* *¦THEINTERRUPTISFORMEBINT200ƒBCLR…D0,STATUS(A0)ˆCleartheinterruptbyclearingbusybit1‰SUBQ.Lƒ#4,D0D0isnowequaltothedrivenumber /INTLOOP‚EQU‡*“I'MHEREFROMTHECOMMANDHANDLER9‰MOVE.WƒCCBSR(A5),SR‹Enable68000interruptsatourlevel'*¦sothatotherinterruptsatourlevel'*¦won'tbedelayedwhileweprocessour$*¦interrupt.‚Everyinterrupthandler)*¦shouldmaskitsinterruptatthesource)*¦oftheinterruptandthenquicklylower(*¦thesysteminterruptmaskbyonelevel)*¦toallowthesystemtorespondtoother#*¦interruptsthatoccuratthesame*¦prioritylevel. ‰MOVE.BƒDRIVENUM(A1),D2†variableblock.Copyittotheworking2‰MOVE.LƒD2,D1registerandmulitplybyfourtouse0‰MULU…#4,D1asanoffsettohaveA2pointtothe>‰MOVE.LƒECATABLE(A5),A2†ECApacketforthedrivenumberweare9‰MOVE.Lƒ(A2,D1),A2‹handling:commandsetuporcompletion. 5‰GET_ON_BDA2’CallthemacrotoadjusttheECApacket,‰RTS›addressfordualportedramandreturn. PAGEO*********************************************************************************ˆPROCESSNEXTCOMMAND*G*ˆControlcomestothisco-routinesegmenttoprocessthenextcommand.C*ˆSometimeswe'rerequiredtodoalittlehousekeepingbasedonthe$*ˆtypeofcommandanddatatransfer.*?*ˆEntry:„A0=PhysicaladdressofVME320Memory-MappedI/Oarea/*’A1=Pointertodrive'svariableblockinCCB#*’A2=Pointertodrive'sECAblock*’A5=PhysicaladdressofCCB*!*ˆRegisterusage:…01234567 *™D‚****™A‚PPP…P*O******************************************************************************* /PROCNEXTTST.B„HALFSCTS(A1)‰Testthedatatype.5‰IFTHEN’Ifwehavedonetrack0onaDDfloppy,‰MOVE.Lƒ#FRMT_DD,D2Š*-‰MOVE.BƒD2,N4(A2)ŒRestoreN4inthECAblock.‰MOVE.LƒFORMATD(PC),D2‡*4‰MOVE.WƒD2,SLC(A2)‹RestoretheSLCintheECAblock.8‰MOVE.BƒDRIVTYPE(A1),DRVTYPE(A2)Restorethedrivetype.,‰CLR.B„HALFSCTS(A1)‰CleartheHALFSCTSflag.‰ENDI 6‰MOVE.LƒIOSECTOR(A1),D0†Getthelogicalsectornumber.4‰BSR†LSN2CHSŽConverttocylinder-head-sectornumber.:‰CMP.B„#FMTFUNC,IOFUNCT(A1)Ifthisistheformatcommand, ‰IFTHEN4‰BSR†BLDBUFFŽBuild/Setthebufferfieldsforformat.‰ELSE4‰BSR†CHS2BUFŽSetthebufferfieldsforread&write.‰ENDI :PROCQUE‚BSR†GET_ADDRGetthedrivenumberandECAaddress. 6‰MOVE.Bƒ#0,MAINSTAT(A2)†Clearthemainstatusbyteand=‰MOVE.Wƒ#0,NUMBYTE(A2)‡Numberofbytestransferredfromlast.2‰ADDQ.Lƒ#4,D2Fixdrivenumbertoequalbitnumber *¦tosetintheSTATUSregister. ;‰BSET…D2,STATUS(A0)ˆTellthecontrollertoprocesscommand! PAGE;INTNEXT‚BSR.L„INTRTN‘TheVME320controllerneedstimetodo**¦itsjobsoreturncontroltothesystem.)*¦WhentheVME320controllerhasfinished$*¦itscurrenttask,we'llreceivean&*¦interruptthatwillcausecontrolto(*¦comebackhere.‚Theco-routinelinkage)*¦convenientlyallowsustocalltherest&*¦ofthesystemasifitweresimplya)*¦subroutinetobeexecutedwhilewehave*¦nothingbettertodo. PAGE*¦THEINTERRUPTENTERSHERE ;‰MOVE.BƒMAINSTAT(A2),D0ˆGetthestatusbitsfromtheVME3207‰BNE.L„CHECKERRcontroller'sstatusbyteintoD0.B,and(*¦reportanerrorifthestatusbitsare&*¦nonzero.‚Astatusbitthatissetin(*¦thecontroller'sstatusbyteindicates*¦anerror. 1‰CMP.B„#1,RTC(A5)Testtheretrycommandflag.‚It1‰BEQ†RESENDmaybe=1ifthiscommandcompletion8‰MOVE.Bƒ#0,RTC(A5)‹wasduetotheaseekafterthefirst"*¦commandcommanderror.‚Branchto&*¦RESENDif=1,clearflagotherwise.* 6‰MOVEQBƒISTACFG,D1IftheNOFINISHflagisnonzero,we8‰TST.B„NOFINISH(A1)‰returnastatuscodeindicatingthat4‰BNE.S„V320DONEtheactualconfigurationofthedisc(*¦doesn'tmatchtheconfigurationinthe%*¦currentconfigurationblock.‚AnI/O)*¦operationfailedtofinishproperly,so&*¦thesectorsizeonthediscprobably&*¦doesn'tmatchthesectorsizeinthe*¦configurationblock. :‰TST.L„IOSCTCNT(A1)‹TheVME320controllerhassuccessfully2‰BNE†PROCNEXTcompletedtheentireI/Otransaction(*¦thatwasspecifiedbythelastcommand(*¦sequencethatwegaveit.‚Ifthereare&*¦anybytesremainingtobeprocessed,'*¦loopbacktoproce ssanotherchunkof*¦theentireI/Otransfer. 9‰MOVE.BƒEOVFLAG(A1),D1‰We'venowcompletedtheentireI/O'*¦transactionthatwasspecifiedbythe$*¦commandthatgeneratedthecurrent%*¦entryoftheI/Oqueue.‚TheEOVFLAG)*¦valuethatwegetherewillbereturned'*¦totheuserasanI/Ostatuscode.If)*¦theI/Otransferwastruncatedtoavoid)*¦runningbeyondtheendofthedisk,the'*¦codeisISTAEOV.Otherwise,wereturn*¦theISTAOKstatuscode. PAGE O*********************************************************************************ˆFINISHPROCESSINGQUEUEENTRY*D*ˆControlcomes‚tothetop‚ofthis‚co-routinewhentheVME320driverC*ˆisreadytofinish‚processing‚thecurrententryofthe‚I/Oqueue.E*ˆEitherwe'vecompletedtheI/OtransactionthatisspecifiedbytheC*ˆcurrententryofthe‚queue,orelsewe've‚runintosomeunreason-G*ˆableproblemthatwecan'tsolve.We'llqueueanI/OcompletioneventC*ˆtotheattachedtask,andwe'll‚removethe‚currententryfromtheD*ˆI/Oqueue.‚IftheI/Oqueuehasanotherentry,we'llloopbackand*ˆstartprocessingit.*?*ˆEntry:„A0=PhysicaladdressofVME320Memory-MappedI/Oarea/*’A1=Pointertodrive'svariableblockinCCB#*’A2=Pointertodrive'sECAblock*’A5=PhysicaladdressofCCB*D1.B=statusvalue*!*ˆRegisterusage:…01234567 *™D‚*** *™A‚PPƒ**P*3*ˆExitsto:‚IDLELOOProutineifI/Oqueueisempty.4*“PROCQUEiftheI/Oqueuecontainsanactiveentry.*O******************************************************************************* V320DONEEQU†*>‰CMP.B„#FMTFUNC,IOFUNCT(A1)‚Ifthiswasaformatcommand,take2‰IFTHEN’thisturnofftosubroutineMEMRTNto1ŠBSR„MEMRTNreturnthesegmentofmemoryallocate‰ENDIšfortheformatbuffer. =EQ610„REG†D0/D2/A1/A3/A4‰WeuseaMOVEM.Linstructiontopull@‰MOVEM.L‚IOBUFLOC(A1),EQ610ƒseveralvariablesoutofthecurrent'*¦I/Opacketinonestep.‚Thisinstruc-(*¦tionsetsuptheregistersasfollows. L1‡SET†IOBUFLOCD0=IOBUFLOC.L1‡SET†IOBUFPTRD2=IOBUFPTR.L1‡SET†IOBUFTCBA1=IOBUFTCB.5L1‡SET†DCBPNTRŽA3=DCBPNTR.‚(ForsubroutineQEVENTI)5L1‡SET†IOCBPTRŽA4=IOCBPTR.‚(ForsubroutineQEVENTI) $*¨TheSETinstructionsthatareused'*¦herearejustdummyinstructionsthat&*¦generateartificiallabelreferences*¦fortheconcordancelisting. PAGE1‰SUB.L„D0,D2’Nowcomputethenumberofdatabytes=‰MOVE.LƒD2,IOSLEN(A4)ˆthatweactuallytransferred,andstore&*¦thatnumberintotheIOSLENfieldof%*¦theIOCB.‚ForanI/Ooperationthat%*¦doesn'tinvolvethetransferofany%*¦read/writedata,wehaveIOBUFLOC=)*¦IOBUFPTR,soweproperlysetIOSLEN=0*¦inthiscase. $‰MOVE.LƒA3,-(A7)Saveaworkingreg.4‰LEA†ERRDISK(PC),A3‰Determinewhethertheerrorcode;CHK_C„MOVE.Bƒ(A3)+,D2returnedisonethatwillrequirethe6‰BEQ.S„NO_COPYŽIOSRRNfieldoftheIOCBtobeupdated.3‰CMP.B„D2,D1Ifitis,copytheVERSAdossectorno.)‰BNE.S„CHK_CcontainedinD3totheIOCB.‰MOVE.LƒD3,IOSRRN(A4),NO_COPY‚MOVE.Lƒ(A7)+,A3Restoreworkingreg. -‰BSR†QEVENTISubroutineQEVENTIqueuesanI/O(*¦completioneventtotheattachedtask.)*¦RegistersA5,A4,A3,andD1.Bmustall)*¦besetproperlywhenwecallsubroutine *¦QEVENTI. 9‰SUB.B„#1,TCBIOCNT(A1)ˆDecrementthecountofoutstanding'*¦I/Ooperationsforthetaskthatowns)*¦theI/Obuffer(ortheIOCBinthecase*¦ofaformatcommand). 6EQ630„REG†A1/A3/A4HereweremovethefrontentryfromE‰MOVEM.L‚IOQUEUE+4(A5),EQ630‚theI/Oqueue,andwesetA1topointtoB‰MOVEM.L‚EQ630,IOQUEUE(A5)„thedriveblockforthediskdrivethat&*¦isassociatedwiththenext(ifany)*¦entryoftheI/Oqueue. 7‰SUB.W„#4,IOQCNT(A5)ŠReducethequeue-countpointerand5‰BHI†PROCQUEŽloopbackifnextentryisstillactive. PAGEO*********************************************************************************ˆIDLELOOPROUTINE*G*ˆThisroutineisentere dwhenthecontrolleriscaughtupwithalltheF*ˆworkandthecontrollerisidle.‚We'llreturncontroltothesystem.**ˆExit:…ReturntoCMRviaRTS*O******************************************************************************* 7IDLELOOPBSR.S…INTRTNTheI/Oisalldone,sowereturn*¦controltothesystem. O********************************************************************************2*ˆModifiedtorunwithspuriousinterruptsƒ2/16/84*O******************************************************************************* BV320IDLEADD.B…#1,SPURINT(A5)ˆIfcontrolevergetshere,wehavea@‰CMP.B…#$80,SPURINT(A5)„SPURIOUSINTERRUPTANDWESIMPLYRETURN.4‰BNE.S…IDLELOOPŒIfthenumberofspuriousinterrupts9‰ST.B†V320DOWN(A5)ˆreaches$80,thensetthechanneldown1‰BRA.S…IDLELOOPŒandreturntotheidleloopuntil*¦anothercommandgetsusout.*"*¦NOTE:$80isanarbitraryvalue.#*¬Chancesarethatifthenumberof"*¬spuriousinterruptsreachesthis *¬number,thediskcontrolleris *¬failing. PAGEO*********************************************************************************ˆINTERRUPT-RETURNROUTINE*G*ˆControlreachesthispointintheVME320interrupthandlerwhenwe'veC*ˆfinishedexectutingaco-routinesegment‚andwewishto‚returntoC*ˆthesystem.‚Wereturn‚controltothesystemwheneverwemustwaitB*ˆonacontroller‚activity,‚andwedependonan‚interrupttobringC*ˆcontrolbacktouswhenthecontrollerhasfinisheditsactivity.*B*ˆWerestore‚theregistersthatweresavedatthebeginningoftheC*ˆinterrupthandler,settheSR,andsettheC-bittoindicatethat(*ˆwe'veprocessedtheinterruptforCMR.*?*ˆEntry:„A0=physicaladdressofVME320Memory-MappedI/Oarea*’A5=physicaladdressofCCB**ˆExit:…ReturntoCMRviaRTS*O******************************************************************************* FINTRTNƒMOVE.Lƒ(SP)+,INTSWTCH(A5)…Thisroutineiscalledasanordinary'*¦subroutine,sothestackcontainsthe(*¦addressoftheco-routinesegmentthat'*¦shouldbeexecutedinresponsetothe%*¦nextinterrupt.‚Wegetthataddress&*¦outofthestack,andweputitinto*¦theinterruptswitch. <‰MOVEM.L‚(SP)+,RTSREGSŠRestoretheregistersthatweresaved1CARRY„EQU†1<<0‘inINTERUPT,settheSR.Cbit,and4‰OR.B…#CARRY,CCR‹retruntoCMR.‚SettingtheSR.Cbit)‰RTS›indicatesthatwehaveprocessedthe*¦interrupt. *¨Noticethatwedon'traisethe(*¦interruptmasklevel,sotheinterrupt'*¦masklevelisonelevellowerthanit'*¦waswhentheVME320interrupthandler*¦wasinvoked. PAGEO********************************************************************************1*ˆVERSADOSDISKERRORCODESCROSS-REFERENCETABLE*D*ˆTheVERSAdoserrorcodeslistedinthistablerequiretheVERSAdosC*ˆsectornumberbeupdatedintheIOSRRNfieldoftheIOSparameter*ˆblock.*O******************************************************************************* -ERRDISK‚DC.B†ISTACMPD2ˆTheseerrorcodesare/‰DC.B†ISTASPED3ˆrecognizedbytheINITutility,‰DC.B†ISTACRCE3ˆasbeingtheonlyonesthat*‰DC.B†ISTADDME5ˆrequiretheupdateofthe/‰DC.B†ISTADMEECˆIOSRRNfieldoftheIOCBtodo-‰DC.B†ISTAMRKEDˆsectorlockoutwhenValidate&‰DC.B†ISTABDSEFˆSectorsisrequested.‰DS.W†0 PAGE O*********************************************************************************ˆVME320ERRORHANDLINGROUTINE*B*ˆThisroutineisexecutedwhenthemainstatusbyteoftheECAisB*ˆNOTzeroafteracommandcompletioninterrupt,andalsowhenthe?*ˆcommandcompletionwasduetoourownretry.‚HerewesavetheB*ˆcommandcode,statusbytesandnumberofcontrollerretriesfromB*ˆthecommandthathadtheerrorintheCCB.‚AnimportantfunctionC*ˆofthisroutineistogettheVERSAdoserrorcodefromtheVME320C*ˆerrorcode,andcomputetheVERSAdossectornumberfromtheerror*ˆsectornumberwhenrequire d.***ˆEntry:„A2ƒ=Pointertodrive'sECAblock*’A5ƒ=PhysicaladdressofCCB$*’D0.B=MainstatusfromECApacket*!*ˆRegisterusage:…01234567*™D‚*R*R*™A†P…P*"*ˆExit:„D1.B=VERSAdoserrorcode*‘D3.L=VERSAdossectornumber*O******************************************************************************* CHECKERR2‰BTSTWƒ#IOPRTYB,IOOPTS(A1)‚Testretryoptionsbit.3‰IFTHEN‘Ifset,don'tseektotrytocorrect.0ŠBRA.L‚CHK00Branchtobypassdriver-retrycode.‰ENDI &‰CMP.B„#2,RTC(A5)‹Testtheretryflag.5‰IFTHEN’Ifit'sset=2thenreportthiserror.‰BRA.LƒCHK00‰ENDI &‰CMP.B„#1,RTC(A5)‹Testtheretryflag.6‰IFTHEN’Ifit'sset=1thenresendthecommand. ‰BRA.SƒRESEND‰ENDI <‰CMP.B„#1,MAINSTAT(A2)†Ifthemainstatusis'unrecoverable'‰BNE.S„CHK00(branchifnot):‰BTSTW„#7,EXTSTAT(A2)‡Andextendedstatusis'positioning'+‰BEQ.S„CHK00Thenissueaseekandaretry. PAGE*A*ˆForlotsoferrors,aSEEKcommand(recalibrate)andare-issue<*ˆofthecommandwillgetridoftheerror.‚WhenanerrorisB*ˆdetected,wesettheRTCflag=1andissueaSEEKcommand.When=*ˆwereturnwesettheRTCflag=2andre-issuethecommand.;*ˆIftheerrorexistsaftertheseek,orittheerrorstill'*ˆexistsafterthere-issue,reportit.*2‰MOVE.Bƒ#1,RTC(A5)‹Settheflagtoindicateretry.;‰MOVE.BƒCMDCODE(A2),SAVECMD(A5)Savethelastcommandcode.0‰MOVE.Lƒ#0,CMDCODE(A2)‡Setupforarecalibrate.‰BRA†PROCQUEŽSendthecommand. *;RESENDƒMOVE.Bƒ#2,RTC(A5)‹Settheflagtoindicatere-issue.C‰MOVE.BƒSAVECMD(A5),CMDCODE(A2)SettheECAwiththesavedcommand.‰BRA†PROCQUEŽSendthecommand. O*********************************************************************************ˆVME320ERROR-CODETABLE*E*ˆThistabletranslatesVME320errorcodesintoVERSAdoserrorcodes.*O******************************************************************************* * ----‚VME320ErrorCode.* |* |&* V…VME320DefinitionandExplanation. "ERRCODE‚DC.B…ISTACNT‡$00„Noerror.'‰DC.B…ISTAUNR‡$01„Nonrecoverableerror.!‰DC.B…ISTANRˆ$02„Drivenotready.‰DC.B…ISTAICE‡$03„Reserved.7‰DC.B…ISTASAˆ$04„Invalidsectoraddress(outofrange).&‰DC.B…ISTACRC‡$05„Floppydataoverrun.!‰DC.B…ISTAIFˆ$06„Illegalcommand.!‰DC.B…ISTANRˆ$07„Controllerbusy.&‰DC.B…ISTASEK‡$08„Drivenotavailable.‰DC.B…ISTADMC‡$09„DMAerror.6‰DC.B…ISTANRˆ$0A„Commandabort.Sinceweabortourown%*¦commandswithawakeupcall,weuse$*¦drivenotreadyastheerrorcode. AERRCEND‚EQU†*-ERRCODE…Errorcodes$0Bthrough$FFarereportedas0*Ÿ"ISTAICE".Thesecodesarecurrentlyundefined * bytheVME320diskcontroller.‰DS.W…0 PAGE-CHK00„MOVE.Bƒ#0,RTC(A5)‹Cleartheretryflag. 5‰CMP.B„#ERRCEND,D0ŠCheckthattheerrorcodereturned1‰IF‡THENŒfromthecontrollerisvalid.‚Ifit7‰MOVE.Bƒ#ISTAICE,D1Šisoneoftheundefinederrorcodes+‰BRA†CHK_ENDŽreturnthegeneralerrorcode.‰ENDI C‰CMP.B„#CNFGFUNC,IOFUNCT(A1)IfthecommandcompletedwasConfigure+‰IF‡THENŒthenwedonotwanttoreport+ŠCMP.Bƒ#6,D0anerrorunlessitwasInvalid/ŠIF†THENŒCommand.‚Sowebranchoutofthis3‹MOVEQ‚#0,D1routinepretendingtherewasnoerror.‹BRA.S‚CHK_ENDŽ*ŠENDI‰ENDI D‰MOVE.L‚CMDCODE(A2),SAVECMD(A5)Savethecommandcode,statusbytes,C‰MOVE.B‚ACTRETRY(A2),RECNT(A5)‚andactualno.ofretriesintheCCB*¨fordebugpurposes. =‰MOVE.BƒERRCODE(PC,D0),D1†Translatethemainstatusbyteinto(*¦aVERSAdoserrorcodeusingtheVME320*¦ERRORCODETABLE. 0‰MOVE.WƒEXTSTAT(A2),D0‡Readtheextendedstatus.*‰IFTHEN’Ifthereisextendedstatus, 3‰MOVE.Lƒ#16,D2‘Ifamorespecificcodeisspecified8CHK11„SUBQ.Lƒ#1,D2reportitinsteadofthegeneralcode4‰ROR.W„#1,D0inthemainstatusbyte.Sinceonlyone4‰BCC.S„CHK11errorcodeisallowed,reportthefirst.‰NEG.L„D2“onesetintheextendedstatuscode.‰ADD.L„#15,D2*‰MOVE.BƒEXTCOD E(PC,D2),D1„*‰ENDI 4‰LEA†ERRDISK(PC),A4‰Determinewhethertheerrorcode;CHK22„MOVE.Bƒ(A4)+,D2returnedisonethatwillrequirethe6‰BEQ.S„CHK_ENDŽIOSRRNfieldoftheIOCBtobeupdated.3‰CMP.B„D2,D1Ifitis,controlfallsthroughtothe/‰BNE.S„CHK22followingroutinetotranslatethe&*¦physicalsectornumbertoaVERSAdos&*¦sectornumber,tobereturnedinD3. PAGE/‰MOVEQ.L‚#0,D3’Usingtheactualnumberofbytes<‰MOVE.WƒBUFLEN(A2),D3ˆtransferred,andknowingthebytesper;‰SUB.W„NUMBYTE(A2),D3‡sector,calculatewhichsectorofthe5‰DIVU…BPS(A1),D3‹transactionhadtheerrorandaddit3‰MOVEQ.L‚#0,D2tothestartingsectornumbertoget/‰MOVE.WƒD3,D2theerrorphysicalsectornumber.‰MOVE.LƒIOSECTOR(A1),D3+‰SUB.L„D2,D3D3<--logical'error'sector. B*ˆTheNUMBYTEfieldshowshowmanybytesinsectorincrementswereB*ˆsuccessfullytransferred.TheBUFLENfieldsshowshowmanybytes?*ˆwererequested.‚IOSECTORpointstothenextsectorthatwould.*ˆbetransferrediteverythingwassuccessful. >‡BTST.Bƒ#1,DRVTYPE(A2)‰Ifthisisaharddisk,thePSNalready6‡IF‡THENŽequalstheVERSAdossector#sogetout. :ˆBTST.Bƒ#0,DRVTYPE(A2)ˆIfthisisasingle-densityfloppy,3ˆIF‡THENdivideby2togetVERSAdossector#. /‰MOVEQ.L‚#0,D2Thisisadouble-densityfloppy.6‰MOVE.WƒSPT(A1),D2‹Getthesectorspertrackvalueand1‰CMP.L„D2,D3determineifwe'reontrackzero.If5ŠIF‡THEN‹weare,treatassinlge-densityfloppy. 2ŠLSR.L„#1,D2Sowemustbeontracks1-xxx.Toget3ŠSUB.L„D2,D3theVERSAdossector#subtract1/2the)ŠLSL.L„#1,D3numberofsectorspertrack. ŠENDI‰ENDI0‰LSR.L„#1,D3‘Divideby2togettheVERSAdosno.‰ENDI CHK_END‚BRA†V320DONE PAGEO********************************************************************************"*ˆVME320EXTENDED-ERROR-CODETABLE*A*ˆThistabletranslatesVME320extendederrorcodesintoVERSAdos *ˆerrorcodes*O******************************************************************************* * ----‚VME320ErrorCode.* |* |&* V…VME320DefinitionandExplanation. (EXTCODE‚DC.B…ISTAUNR‡Bit0:‚Writefault.,‰DC.B…ISTACRC‡Bit1:‚Correctabledataerror. ‰DC.B…ISTADOˆBit2:‚Dataoverrun)‰DC.B…ISTADME‡Bit3:‚Noidentifierfound.‰DC.B…ISTANRˆBit4:‚Notready./‰DC.B…ISTADDM‡Bit5:‚Deleteddataaddressmark."‰DC.B…ISTAWPˆBit6:‚Writeprotect.'‰DC.B…ISTASEK‡Bit7:‚Positioningerror.'‰DC.B…ISTASEK‡Bit8:‚Dataparttimeout.'‰DC.B…ISTACNF‡Bit9:‚Diskformaterror.4‰DC.B…ISTACRC‡Bit10:Uncorrectabledataerror(ECC)9‰DC.B…ISTANRˆBit11:Commandstopordrivenotavailable.*‰DC.B…ISTACFG‡Bit12:Drivetyperejected.*‰DC.B…ISTASEK‡Bit13:Positioningtimeout.<‰DC.B…ISTADME‡Bit14:WrongID-DATA-IDsequenceduringread.&‰DC.B…ISTABUS‡Bit15:Buserrorfault.‰DS.W…0 PAGE O*********************************************************************************ˆCONTROLLER-ERRORROUTINE*G*ˆControlcomestothis‚routinewhenwe'vedetectedacontrollererror.G*ˆWedeclareacontrollererrorwhenaVME320controllerdoessomethingF*ˆthatsimplycannotbeexplained‚byany‚definedsetofcircumstances.G*ˆWhenacontrollererroroccurs,we‚downtheVME320channelandreportF*ˆacontrollererror.‚Acontrollererrorisaseriousproblem,andthe?*ˆsystemshouldn'ttrytousetheVME320channelfollowingone.*A*ˆThereare‚twoentrypoints.‚Theentrypoint‚atCTRLERR1‚isusedD*ˆtheerrorisdetectedwithinasubroutine.‚TheentrypointCTRLERR*ˆisusedotherwise.*?*ˆEntry:„A0=PhysicaladdressofVME320Memory-MappedI/Oarea/*’A1=Pointertodrive'svariableblockinCCB*’A5=PhysicaladdressofCCB*!*ˆRegisterusage:…01234567 *™D‚*** *™A‚PPƒ**P*>*ˆExitsto:‚V320DONEtoterminateprocessingfortheactivity.*O******************************************************************************* 7CTRLERR1ADDQ.Lƒ#4,SP’Controlcomestothisentrypoint%*¦wh enacontrollererrorisdetected%*¦fromwithinasubroutine.‚Weremove&*¦thesubroutine'sreturnaddressfrom(*¦thestack,sothestackisrestoredto&*¦theconditionthatithadbeforethe*¦subroutinewascalled. 9CTRLERR‚ST.B…V320DOWN(A5)‹Downthechannelbysettingthe"*¦variablethatindicatesthatthe#*¦controllerisdown.‚Ifthesystem**¦triestoaccesstheVME320channelagain#*¦withoutresettingitfirst,we'll%*¦reportanerrorindicatingthatthe$*¦channelisdown.‚Thesystemreally$*¦shouldn'ttrytoaccesstheVME320'*¦channelagainwithoutfirstresetting$*¦thecontroller.‚Evenresettingthe)*¦controllermaynotcorrecttheproblem,'*¦butwe'llletthesystemtryasoften*¦asitwishes. 5‰MOVEQBƒISTACNT,D1SetupD1.Bforreportingastatus4‰BRA†V320DONEcodethatindicatesacontrollererror%*¦andgoterminateprocessingforthe!*¦currententryoftheI/Oqueue. PAGEO********************************************************************************?*ˆTheseconstantsareusedbytheVME320driver.‚Constantswere>*ˆchosenoverequatessothedrivercouldbeeasilypatchedto*ˆoptimizedriveoperation.*O******************************************************************************* =FORMATS‚DC.L†$1B0000E5FormatfieldsN4,N5,SLCandFILLBYTE#*¦forasingle-densityfloppydisk.*=FORMATD‚DC.L†$360001E5FormatfieldsN4,N5,SLCandFILLBYTE**¦fordouble-densityfloppyandharddisk.* A*ˆFloppydisksteppingratetableforfloppydisksasdefinedforL*‚VERSAdos4.3.‚Thevaluesbelowareinmilliseconds.‚ThisdrivertranslatesK*‚thesteppingratecodeintoamillisecondvalueusingthetablebelowforK*‚8"floppydiskdrivesanddoublesthevaluesbelowfor5-1/4"floppydisk *‚drives.* $*“8"…5-1/4"„UnitsƒSteppingRateCode%*’---…------„-----ƒ------------------ SRFCODE‚DC.B‡6ˆ12‡Msec„Default‰DC.B‡3ˆ06‡Msec„00‰DC.B‡6ˆ12‡Msec„01‰DC.B†10ˆ20‡Msec„10‰DC.B†15ˆ30‡Msec„11 *=*ˆHarddisksteppingratetableforharddisksasdefinedforL*‚VERSAdos4.4.Thevaluesbelowareinmilliseconds.‚ThisdrivertranslatesH*‚thesteppingratecodeintoamillisecondvalueusingthetablebelow.* *‘Hard†Units†SteppingRateCode*‘----†-----†------------------ SRHCODE‚DC.B‡0ˆMsec†Default‰DC.B‡6ˆMsec†00‰DC.B†10ˆMsec†01‰DC.B†15ˆMsec†10‰DC.B†20ˆMsec†11 *******************************ˆPATCHAREAŠ*******************************‰DS.B†30 ‰ENDé=/*=/*†M420DRV.AF=/*/=/* Chain file to assemble VME420 (SASI) driver=/*:=/* If no output argument is specified for the listing the)=/* chain file will default to M420DRV.LS=/*=/IFC \1ƒ=ARGM420DRV.LS=/ENDIF=/*$=ASM M420DRV.SA,M420DRV.RO,\1;RZ=186=/*{ Included files are:=/*ƒ9995.&.STR.EQ=/*ƒ9995.&.TCB.EQ=/*ƒ9995.&.CCB.EQ=/*ƒ9995.&.LV5.EQ=/*ƒ9995.&.IOE.EQ=/*ƒ9995.&.NIO.EQ =/*ƒCOMCMD.AI=/*ƒM420INT.AI=/*}=/*=ENDééé ééés‰TTL‡M420DRV.SA¨01/17/83 F***********************************************************************˜MODIFICATIONSŸ*#*ˆDTCFLAGADDED‡RWM&JHŒ11/16/83Œ**ˆIOATMCHANGED‡BWN‘12/12/83Œ**ˆStatuscheckdelayª**ˆincreased‹RV’09/19/84Œ**ˆtestedwithdtc520bRV¦*6*WewillbeusingtheIOASIZEbitoftheattributes…*7*wordtodeterminewhetherwearecontrollingthe8"„*(*diskdriveorthe51/4"diskdrive.“*+*Also,theIOATDENbitisnowsignificant.*Ä*F********************************************************************** ‰OPTCRE,PCS**ˆMisc.equates* "DRIVESƒEQU‡4‰#ofdrivesperboardEXEC…EQU‡0‰RMS68Ktrap# &DTYPE„EQU‡0‰Conditionalassemblyflag:*œ0=assembleforSASIdriver$*œ1=assembleforWinchesterdriver **‰Macrosusedbythisdriver* 4LONGWORDMACRO„.–Thismacroskipszeroormorebytes'*¦inmemory(ifnecessary)toalignthe)*¦assembler'slocationcountertoalong-&*¦wordboundary.‚Wedefinealong-word)*¦boundarytobealocationwhoseaddress*¦isevenlydivisibleby4.‰DS.W…00‰IFNE…*/4*4-*Ifthelocationcounterisn'tona-‰DS.W…1”long-wordboundary,advanceitbyone/‰ENDC….”wordtoputitonalong-wordboundary.‰ENDM 3MOVEIAƒMACRO„.–Thismacroisusefulwhenwewantto%*¦putanimmediatevalueintoan*¦register."*¦[]MOVEIAƒ,An2‰IFLE…\1-$7FFFIftheimmediatevalueislessthan/‰IFGE…\1+$8000orequalto$7FFFanditisalso2‰MOVE.Wƒ#\1,\2greaterthanorequalto-$8000,it.‰MEXIT„.”fitswithina16-bitwordasasigned*‰ENDC….”value.‚Inthiscase,weuseatwo- ‰ENDC….”wordMOVE.Winstruction.2‰MOVE.Lƒ#\1,\2‘Otherwise,wemustuseathree-word*¦MOVE.Linstruction.‰ENDM PAGE4MOVEQBƒMACRO„.–Thismacroisusefulwhen(1)wewant(*¦toemployaMOVEQinstructiontoputa'*¦valueintotherightmostbyteofaDn%*¦registerand(2)wedon'tcarewhat(*¦valuegoesintotheotherbytesofthe*¦Dnregister."*¦[]MOVEQBƒ,Dn|B…?4•:9¥9'µ0½:Å8Í4Õ;Ý7å7í.õ:ý87 829%9-:5:=6E5M8U8]2e2.‰IFGT…\1-$7F‘Iftheimmediatevalueisgreater1‰IFLE…\1-$FFthan$7Fanditisalsolessthanor?‰MOVEQ„#\1+$FFFFFF00,\2…equalto$FF,providesignextensionat(‰MEXIT„.”thesourceleveltopreventthe/‰ENDC….”assemblerfromgivingawarningmessage‰ENDC….”thatwedon'twant.3‰MOVEQ„#\1,\2‘Otherwise,usetheimmediatevalueas'*¦itis.‚Iftheimmediatevalueisout-$*¦sidetherangethatcanfitintoa$*¦singlebyte,we'llgetanerrorto*¦alertustotheproblem.‰ENDM 4MOVEQWƒMACRO„.–Thismacroisusefulwhen(1)wewant$*¦toputanimmediatevalueintothe)*¦rightmostwordofaDnregisterand(2)(*¦wedon'tcarewhatvaluegoesintothe *¦otherwordoftheDnregister."*¦[]MOVEQWƒ,Dn0‰IFLE…\1-$7F‘Ifth eimmediatevalueislessthan3‰IFGE…\1+$80orequalto$7Fanditisalsogreater5‰MOVEQ„#\1,\2thanorequalto-$80,itfitswithina/‰MEXIT„.”singlebyteasasignedvalue.‚Inthis-‰ENDC….”caseweuseaone-wordMOVEQinstruc- ‰ENDC….”tion.0‰MOVE.Wƒ#\1,\2‘Otherwise,wemustuseatwo-word*¦MOVE.Winstruction.‰ENDM PAGE#*‰Includethestandardequatefiles*‰INCLUDE‚9995.&.STR.EQ*‰INCLUDE‚9995.&.TCB.EQ*‰INCLUDE‚9995.&.CCB.EQ*‰INCLUDE‚9995.&.LV5.EQ*‰INCLUDE‚9995.&.IOE.EQ*‰INCLUDE‚9995.&.NIO.EQ ŠTTL†9995.&.STR.EQŠINCLUDE‚9995.&.STR.EQŠTTL†9995.&.TCB.EQŠINCLUDE‚9995.&.TCB.EQŠTTL†9995.&.CCB.EQŠINCLUDE‚9995.&.CCB.EQŠTTL†9995.&.LV5.EQŠINCLUDE‚9995.&.LV5.EQŠTTL†9995.&.IOE.EQŠINCLUDE‚9995.&.IOE.EQŠTTL†9995.&.NIO.EQŠINCLUDE‚9995.&.NIO.EQŠTTL†M420DRV.SA LIST PAGE*!*ˆParametersMaskforSASIDriver* &*¨Noticethatsomeofthedefinedbits>*ƒ15‚14‚13‚12ƒ11‚10ƒ9ƒ8„intheparametersmaskarenotusedbyI*‚+---+---+---+---++---+---+---+---+‚theSASIdriver,butallofthebits8*‚|‹|ƒ||ƒ|ƒ|ƒ|ƒ|‚thataredefinedforanydiscdriveare=*‚+---+---+---+---++---+---+---+---+‚showninthediagrams.{*„^ƒ^ƒ^ƒ^„^ƒ^ƒ^ƒ^*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ|:*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ----1=IOSSOFissignificant(notused).*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|1*„|ƒ|ƒ|ƒ|„|ƒ|ƒ--------1=IOSPSMissignificant. *„|ƒ|ƒ|ƒ|„|ƒ|>*„|ƒ|ƒ|ƒ|„|ƒ------------1=IOSSHDissignificant(notused).*„|ƒ|ƒ|ƒ|„|A*„|ƒ|ƒ|ƒ|„----------------1=IOSTRKDissignificant(notused). *„|ƒ|ƒ|ƒ|D*„|ƒ|ƒ|ƒ---------------------1=IOSPCOMissignificant(notused).*„|ƒ|ƒ|F*„|ƒ|ƒ-------------------------1=IOSSPTDissignificant(notused).*„|ƒ|G*„|ƒ-----------------------------1=IOSSRBissignificant(notused).*„|K*„---------------------------------1=IOSRWCCBissignificant(notused). *„7ƒ6ƒ5ƒ4„3ƒ2ƒ1ƒ0$*‚+---+---+---+---++---+---+---+---+*‚|ƒ|ƒ|ƒ|ƒ||ƒ|ƒ|ƒ|ƒ|$*‚+---+---+---+---++---+---+---+---+*„^ƒ^ƒ^ƒ^„^ƒ^ƒ^ƒ^*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ|/*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ----1=IOSRECissignificant.*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|1*„|ƒ|ƒ|ƒ|„|ƒ|ƒ--------1=IOSRSZissignificant. *„|ƒ|ƒ|ƒ|„|ƒ|>*„|ƒ|ƒ|ƒ|„|ƒ------------1=IOSWTOissignificant(notused).*„|ƒ|ƒ|ƒ|„|@*„|ƒ|ƒ|ƒ|„----------------1=IOSRTOissignificant(notused). *„|ƒ|ƒ|ƒ|8*„|ƒ|ƒ|ƒ---------------------1=IOSSPTissignificant.*„|ƒ|ƒ|:*„|ƒ|ƒ-------------------------1=IOSHDSissignificant.*„|ƒ|<*„|ƒ-----------------------------1=IOSTRKissignificant.*„|>*„---------------------------------1=IOSILVissignificant. PAGE 6L0190„EQU†1<L0192„EQU†1<L0200„EQU†1<L0202„EQU†1<*„|ƒ|ƒ|ƒ---------------------1=Rigiddisc;0=floppydisc.*„|ƒ|ƒ|G*„|ƒ|ƒ-------------------------1=Doubledata-density(MFM)ondrive.*„|ƒ|¡(NotusedbySASI).D*„|ƒ-----------------------------1=Doubletrack-densityondrive.*„|¥(NotusedbySASI).K*„---------------------------------1=Seekreq'dw/headswitchondrive.*ª(NotusedbySASI). IOPDMNTBEQU†126L0140„SET†1<*‚1=DoubleSided----------‰ofthecontrolcodeareignored. -‰PAGEš#######################################E*ˆThesevariablesdefinethecommandpac ketthatwasdescribedabove. *‰DS.W…0–Thecommandpacketmustbeginona'*¦wordboundarybecausewedon'talways(*¦usebyte-modeaddressingtoaccessit. 2CMDOP„DS.B…1–TheCMDOPfieldofthecommandpacket)*¦containstheopcodethattellstheSASI'*¦controllerwhatoperationtoperform.$*¦Forexample,theCMDOPfieldmight)*¦containanopcodethatspecifiesaread)*¦operation,awriteoperation,aformat-'*¦discoperation,aformat-trackopera-%*¦tion,oradefine-formatoperation.'*¦Pleaserefertotheinterrupthandler*¦fordetails. 2CMDLSNƒDS.B…3–TheCMDLSNfieldofacommandpacket:LSNMASK‚EQU†$001FFFFFŒoftencontainsalogicalunitnumber5LUNFIELDEQU†5”andalogicalsectornumbertospecify)*¦aparticularareaofaparticulardisc.&*¦TheLSNMASKvalueisabitmaskthat$*¦indicateswhichbitsoftheCMDLSN(*¦fieldcanbeusedforalogicalsector)*¦number,andtheLUNFIELDvalueisabit)*¦numbertoindicatethatbits5-7ofthe)*¦firstbyteoftheCMDLSNfieldareused"*¦fortheLUNfield.‚TheLUNfield)*¦containsthecontroller-definedlogical)*¦unitnumber,whichisequivalenttothe*¦channeldevicenumber. 4CMDSECTSDS.B…1–TheCMDSECTSfieldcontainsasector8CMDILVƒEQU†CMDSECTScountforareadorwriteoperation,&*¦anditcontainsaninterleavefactor&*¦foraformatoperation.‚TheCMDSECTS&*¦fieldalwayscontainsthevaluezero *¦foradefine-formatoperation. /MAXSECTSEQU†255”Thislabeldefinesthemaximum(*¦possiblevaluethatcanbeusedinthe'*¦CMDSECTSfield.‚IfanI/Otransaction)*¦involvesmorethanMAXSECTSsectors,we(*¦mustbreakupthetransactionintotwo*¦ormoresmallertransactions. *Â(Continued)-‰PAGEš#######################################@*ˆThesevariablesareacontinuationoftheSASIcommandpacket. 2CMDCTRL‚DS.B…1–TheCMDCTRLfieldofaSASIcommand3NORETRY‚EQU†7”packetcontainsacontrolcode.‚Bit74NOCORRƒEQU†6”ofthecontrolcodeinanormalcommand)*¦packetcanbesettodisablecontroller(*¦retries,andbit6ofthecontrolcode'*¦inanormalcommandpacketcanbeset'*¦todisabledataerrorcorrection.‚The(*¦SASIcontrollerordinarilyignoresthe%*¦remainingbitsofthecontrolcode. 0CMDDSIDEEQU†0–WhenaSASIcontrollerreceivesa5CMDDDEN‚EQU†1”define-formatcommand,thecontrol-code&*¦fieldisinterpreteddifferently.‚In&*¦thiscase,bit0ofthecontrolcode&*¦canbesettospecifyadouble-sided'*¦floppydisc,andbit1ofthecontrol&*¦codecanbesettospecifyadouble-%*¦densityfloppydisc.‚Thecontroller&*¦simplyignorestheremainingbitsof&*¦thecontrolcodeforadefine-format *¦command.***ƒEquateadded1/10/84„BWN*,CMDDDEN2EQU‡2“Forthe1403ESboard,wealso#*¦mustsetbit2toindicatedouble *¦density* 0CMDENDƒEQU†*–ThelabelCMDENDisattachedtothe9CMDLENƒEQU†CMDEND-CMDOP‰bytethatimmediatelyfollowsthe&*¦commandpacketinmemory,andCMDLEN(*¦specifiesthelength(inbytes)ofthe'*¦commandpacket.‚Wesometimesstartat'*¦locationCMDENDandaccessthefields&*¦inthecommandpacketbyusingauto-*¦decrementaddressing. -DTCCMDƒDS.B†6“THISCOMMANDBLOCKCONTAINSTHE%*¦DTC520ACOMMANDFORCONFIGURATION.*DTCDATA‚DS.B†10’THISISTHEDATABLOCKFOR*¦PARAMETERSOFDTCCMD. B*ˆThis‚point‚marks‚the‚endofthecommand-packetsubsectionoftheF*‚channel-related‚part‚ofthedevice-dependentportionoftheCCB.ƒTheG*‚definitionsofchannel-relatedCCBvariablesresumeonthenextpage.-‰PAGEš#######################################*F*ˆThevariablesthataredefinedbelowarepartofthechannel-related2*‚portionofthedevice-dependentareaoftheCCB.* 5INTSWTCHDS.L…1–Weusethisvariabletoimplementthe(*¦co-routinelinkagethatisusedinthe&*¦SASIinterrupthandler.‚Wheneverthe%*¦interrupthandlerreceivescontrol,'*¦thisvariablecontainstheaddressof)*¦thenextcodesubsectionthatshouldbe$*¦executedintheinterrup t-handling%*¦routine.‚Thustheinterrupthandler#*¦caneasilystartexecutingatthe%*¦correctpointwheneveraninterrupt *¦occurs. $*¨WeinitializeINTSWTCHtopointto#*¦theSASIIDLEroutine,sowe'llbe'*¦protectedincasetheSASIcontroller(*¦somehowerroneouslycreatesaspurious%*¦interruptbeforethecontrollerhas*¦evenbeenaccessed. 2INTTEMP‚DS.L…1–This4-bytevariableisusedbythe&*¦SASIinterrupthandlerfortemporary&*¦storage.‚Theinterrupthandlerneeds(*¦temporarystorageoutsidethestackso(*¦itcanstoreavalueandthenretrieve%*¦thesamevaluewhileprocessingthe$*¦nextinterrupt.‚Thestackcan'tbe$*¦usedacrossinterruptsbecausethe)*¦stackmustalwaysbeunchangedwhenthe&*¦interrupthandlerreturnscontrolto *¦thesystem. 7IOQUEUE‚DS.L…DRIVES‘TheIOQUEUEisusedtoindicatethe(*¦I/Oactivities(ifany)thatarelined'*¦upwaitingtobedoneunderinterrupt(*¦controlbytheSASIinterrupthandler.'*¦Sincewecanneverhavemorethanone'*¦commandpendingforanysingledrive,(*¦theIOQUEUEhasexactlyenoughentries%*¦toaccommodateoneI/Oactivityfor'*¦eachdrivethataSASIcontrollercan*¦possiblycontrol. *Â(Continued)-‰PAGEš#######################################$*¨AnentryintheIOQUEUEisalong-)*¦wordpointerthatcontainsthephysical(*¦addressofadrive'svariableblockin'*¦thedrive-associatedareaoftheCCB,(*¦andthevaluesinthedrive'svariable&*¦blockdescribetheI/Oactivitythat*¦mustbedonewiththatdrive. '*¨TheSASIdriverputsentriesintothe'*¦IOQUEUEintheorderinwhichtheI/O)*¦requestsarereceived,sonodriveona$*¦SASIchannelhaspriorityoverany'*¦otherdriveonthesamechannel.‚When$*¦theSASIdriverreceivesanewI/O%*¦request,thedriversimplyputsthe&*¦entryforthatrequestintothenext *¦availableslotoftheIOQUEUE. '*¨WhentheSASIdrivercompletesanI/O&*¦activityunderinterruptcontrol,it(*¦movesallremainingIOQUEUEentriesup%*¦byonepositionintheIOQUEUE.‚The(*¦physicalmovementofqueueentriesmay%*¦soundlikeapoorapproachatfirst&*¦glance,butitturnsouttobequite%*¦good.‚Theuseofwrappingfrontand$*¦rearqueuepointerswithposition-(*¦independentcodeisrathercumbersome,$*¦andthephysicalmovementofqueue%*¦entriesisabettertechniquefora"*¦shortqueuesuchastheIOQUEUE.-‰PAGEš#######################################,‰LONGWORD˜TheSASIinitializationsubroutine.CCBZERO‚EQU†*”clearsallmemorylocationsfrom$*¦CCBZEROthroughtheendoftheCCB'*¦area,sotheCCBfieldsatandbeyond'*¦CCBZEROallhaveinitialvaluesequal(*¦tozero.‚NoticethatweuseaLONGWORD&*¦macroheretoensurethatCCBZEROis%*¦alignedonalong-wordboundary,so&*¦CCBZEROhasamemoryaddressthatis!*¦evenlydivisibleby4.‚TheSASI)*¦initializationroutineclearstwowords(*¦atatime,andweneedtohaveCCBZERO%*¦onalong-wordboundarytomakethe'*¦initializationroutineworkproperly. 1IOQCNTƒDS.W…1–Thisvariablecontainsthecountof#*¦thenumberofbytesintheactive)*¦entriesintheIOQUEUE,soIOQCNT=4*N)*¦whereNisthenumberofactiveentries(*¦intheIOQUEUE.‚ThevalueofIOQCNTis$*¦alwaysintherangefrom0through&*¦through4*DRIVES,sowecouldeasily&*¦useasinglebyteforthisvariable.(*¦However,weuseafullwordforcoding%*¦convenience.‚NoticethatIOQCNTcan%*¦beusedasanoffsetpointertothe&*¦nextavailableentryintheIOQUEUE. '*¨IOQCNTmustbeinitializedtozeroat*¦system-initializationtime. 1DRVBLKƒDS.W…0–TheDRVBLKareacontainsallofthe(*¦CCBvariablesthatareassociatedwith(*¦anindividualSASIdiscdrive,andthe&*¦entirevariableblockisrepeatedas!*¦necessarytoprovideacomplete'*¦variableblockforeachdiscdriveon&*¦thechannel.‚Thevariableblockthat&*¦correspondstoaparticulardriveis#*¦determinedbythedrive's channel#*¦devicenumber.‚Thefirstvariable#*¦blockcorrespondstodrive0,the&*¦secondvariableblockcorrespondsto*¦drive1,etc. &*¨Besidesmarkingthebeginningofthe&*¦drive-associatedportionoftheCCB,'*¦thelabelDRVBLKdefinesthesize(in$*¦bytes)ofthepartoftheCCBthat'*¦precedesthedrive-associatedareaof *¦theCCB.-‰PAGEš#######################################-‰OFFSETƒ0–WeincludethisOFFSETstatementso%*¦thatallofthevariablesinadisc(*¦drive'svariableblockwillbedefined)*¦asoffsetsrelativetothebeginningof*¦thedrive'svariableblock. 3ACTIVEƒDS.B…1–Thisvariableisusedtoindicatethe'*¦currentactive/inactivestatusofthe*¦associateddiscdrive. &*¨Adiscdriveissaidtobeactiveif%*¦theSASIdriverhaseverreceiveda(*¦configureordefaultconfigurecommand&*¦forthedrive.‚Inactualpractice,a$*¦discdriveisactivatedatsystem-&*¦initializationtimewhenIOSsendsa$*¦configurecommandtoconfigurethe%*¦drivetoitssysgen-defineddefault*¦configuration. %*¨Adiscdriveissaidtobeinactive)*¦iftheSASIdriverhasneverreceiveda(*¦configureordefaultconfigurecommand(*¦forthedrive.‚Inthiscase,thedrive*¦maynotevenexist. '*¨TheSASIdriverusesadrive'sACTIVE&*¦flagasanindicatorthatallowsthe)*¦drivertodosomeuniqueprocessingfor%*¦thefirstconfigurecommandthatis'*¦receivedforthediscdrive.‚Formore%*¦detailspleaserefertotheroutine%*¦thatimplementsthefunctionofthe*¦configurecommand. $*¨IfACTIVE[DRIVE]=0,thedriveis(*¦notactive.‚WhenACTIVE[DRIVE]isnon-%*¦zero,however,thedriveisactive.-‰PAGEš#######################################4MOUNTED‚DS.B…1–Thisvariableisusedtoindicatethe&*¦currentmounted/dismountedstatusof*¦theassociateddiscdrive. &*¨Duringsysteminitializationaftera(*¦boot-up,theVersadosoperatingsystem(*¦automaticallyperformsaconfigureand$*¦mountcommandforeachdiscinthe%*¦system.‚Later,whenauserwantsto&*¦changethediscinadrive,theuser'*¦mustusethedismountcommandtotell%*¦thesystemthatthecurrentdiscis(*¦beingremovedfromthedrive,andthen(*¦theusermustusethemountcommandto%*¦tellthesystemthatanewdischas*¦beeninsertedintothedrive. #*¨Thediscissaidtobedismounted$*¦followingaconfigureanddismount'*¦command,andtheSASIdriverdoesnot&*¦permitread,write,orformatopera-'*¦tionswithadiscthatisdismounted. &*¨Thediscissaidtobemountedagain&*¦followingasuccessfulconfigureand*¦mountcommand. $*¨IfMOUNTED[DRIVE]=0,thediscis$*¦dismounted.‚WhenMOUNTED[DRIVE]is(*¦nonzero,however,thediscismounted.-‰PAGEš#######################################8CONFGBLKEQU†*-IOSATWThisportionofadrive'svariable6‰DS.B…IOSDLN-IOSATWˆblockcontainsthedrive'scurrent(*¦configurationvalues.‚Thestructureof$*¦thisportionofadrive'svariable"*¦blockisalmostidenticaltothe&*¦structurethatwasdescribedearlier(*¦foraconfigure/statusparameterblock'*¦thatisusedwithaconfigurecommand'*¦orastatuscommandforadiscdrive.!*¦Theonlydifferencebetweenthe)*¦structureofthisvariableareaandthe)*¦structurethatwasdescribedearlieris"*¦thatthisvariableareadoesnot&*¦containanyofthefieldsbeforethe%*¦IOSATWfield.‚ThelabelCONFGBLKis(*¦offsettocompensateforthefactthat$*¦thefieldsbeforetheIOSATWfield%*¦don'texisthere,sowecanusethe%*¦samelabelsthatweredefinedfora#*¦configure/statusparameterblock. &*¨TheSASIdriverdoesn'tneedtokeep(*¦copiesofanyofthefieldsbeforethe!*¦IOSATWfieldbecausethedriver&*¦dynamicallydeterminesthevaluesof"*¦thosefieldsastheyareneeded. '*¨TheSASIdriverchangesthevaluesin$*¦theCONFGBLKareainresponsetoa$*¦configurecommand,anditusesthe(*¦valuesintheCONFGBLKareatorespond*¦toastatuscommand. $*¨Wedon'tneedto initializeanyof)*¦thevaluesintheCONFGBLKareabecause)*¦weareguaranteedthatsomesystemtask'*¦willissueaconfigurecommandasthe(*¦firstcommandthatwereceiveforeach&*¦discdrive.‚Believingthisguarantee'*¦leavestheSASIdrivervulnerable,of(*¦course,butadrivercan'tbeexpected)*¦tobeinvulnerabletoerrorsinhigher-*¦levelsystemsoftware.-‰PAGEš#######################################4SCTPVRECDS.W…1–Thisvariabletellshowmanylogical(*¦sector(s)thereare(asthediscdrive&*¦iscurrentlyconfigured)inasingle$*¦Versadosrecord.‚Thevalueofthis)*¦variableiscomputedasVDOSRSZ/IOSPSM,(*¦andwereportaconfigurationerrorif(*¦thedivisiondoesnotyieldaninteger*¦quotientwithnoremainder. &*¨Thisvariableiseffectivelypartof)*¦thediscdrive'scurrentconfiguration,&*¦butitisnotofficiallypartofthe'*¦configurationblock.‚Thisvariableis#*¦setbyaconfigurecommand,soit"*¦alwaysreflectsthediscdrive's&*¦currentconfiguration.‚Thisvariable#*¦isnotsetbyadefaultconfigure&*¦commandbecausethevariablerelates'*¦onlytothedisc'scurrentconfigura-)*¦tion,nottoitsdefaultconfiguration. $*¨WeneedthisvariablefortheSASI$*¦driversowecantranslatelogical'*¦sectorsintoVersadossectorstomake%*¦theVersadosoperatingsystemthink&*¦thatourSASIdiscscontainVersados!*¦sectors.‚Thisvariableisn'tan$*¦officialpartoftheconfiguration)*¦block,though,becausethisvariableis)*¦meaningfulonlywithintheSASIdriver.-‰PAGEš#######################################F*ˆThefollowingportionofadrive'svariableblockcontainsvariablesL*‚thatareusedtodescribethecurrentstatusofanI/OtransactionfortheK*‚drive.‚ThesevariablesareinitiallysetupbythecommandprocessorwhenL*‚anI/Ocommandisprocessed,andtheyaresubsequentlyused(andsometimesJ*‚updated)bytheSASIinterrupthandler.ƒWefrequentlyrefertothispartJ*‚ofadrive'svariableblockasitsI/Opacket.ƒTheendoftheI/Opacket"*‚ismarkedbythelabelIOPKTEND. D*ˆ[******Warning******]ƒThevariablesinthissectionofadrive'sG*‚variable‚block‚must‚appearinthe‚exactorderthatisshownbelow.ƒWeJ*‚sometimesaccesstheindividualvariablesinthissectionasanarrayofK*‚variablesbyautodecrementing‚fromlocationIOPTKENDinsteadofaccessing3*‚thevariablesbytheirindividualvariablenames. /NOFINISHDS.B…1–Weinitiallyclearthisbyteby"*¦storingzerointoitwhilewe're)*¦storingtheHALFSCTSvalue(seebelow).'*¦Welatersetthisbytenonzerointhe&*¦interrupthandlerifareadorwrite)*¦transactionabortsprematurelyorfails'*¦tofinishwhenitshould,andthenwe)*¦usethisvariableasaflagtoindicate$*¦thatareadtransactionorawrite#*¦transactionhasusedanincorrect*¦numberofbytes. 1HALFSCTSDS.B…1–Forareadtransactionorawrite'*¦transaction,thisvariablecontainsa%*¦countofthenumberofhalfsectors&*¦thatremaintobetransferred.‚Fora(*¦formatcommandoraconfigurecommand,'*¦thisvariableequalszerotoindicate'*¦thatnohalfsectorsshouldbetrans- *¦ferred. %*¨So-calledhalfsectorsariseinthe'*¦caseofanI/Otransferthatinvolves'*¦trackzeroofadouble-densityfloppy&*¦disc.‚Thesectorsintrackzeroofa)*¦double-densityfloppydiscarerecorded)*¦insingledensity,sothosesectorsare(*¦onlyhalfaslargeasanyoftheother$*¦sectorsonthedisc.‚Naturally,we&*¦musttreatthehalfsectorssomewhat(*¦differentlyfromthewaywetreatfull *¦sectors. $*¨IfanI/Otransferdoesn'tinvolve'*¦trackzeroofadouble-densityfloppy%*¦disc,thenumberofhalfsectorsis*¦zero.-‰PAGEš#######################################?*ˆThesevariablesareacontinuationofthedrive'sI/Opacket. 1IOSCTCNTDS.L…1–Forareadtransactionorawrite'*¦transaction,thisvariablecontainsa(*¦countofthenumberoflogic alsectors&*¦thatremaintobetransferred.‚Fora(*¦formatcommandoraconfigurecommand,'*¦thisvariableequalszerotoindicate(*¦thatnosectorsshouldbetransferred. %*¨Noticethatthisvariableisalways'*¦computedintermsoflogicalsectors.#*¦Itisneverexpressedintermsof*¦Versadosrecords. 1IOSECTORDS.L…1–Forareadtransactionorawrite)*¦transaction,thisvariablecontainsthe$*¦logicalsectornumberofthefirst(*¦sectorofthenextblockofsectorsto%*¦betransferred.‚TheSASIcontroller(*¦canhandleamaximumof255sectorsin'*¦asinglecommandsequence,sowemust&*¦makemultiplecontrollerrequeststo(*¦completeanI/Otransferthatinvolves*¦morethan255sectors. "*¨Foraformat-trackcommand,this&*¦variablecontainsthelogicalsector(*¦numberofsomesectorwithinthetrack(*¦thatistobeformatted.‚Foraformat-)*¦disccommand,thisvariableisnormally%*¦zero,anditsvalueismeaningless. %*¨Theinitialvalueforthisvariable)*¦isderivedfromtheIOSRRNfieldofthe'*¦IOCBfortheI/Ocommandinthecases"*¦mentionedabove.‚Foraconfigure(*¦command,thisvariableisalwayszero. %*¨Noticethatthisvariableisalways'*¦computedintermsoflogicalsectors.#*¦Itisneverexpressedintermsof*¦Versadosrecords.-‰PAGEš#######################################?*ˆThesevariablesareacontinuationofthedrive'sI/Opacket. 1IOBUFLOCDS.L…1–Forareadtransactionorawrite)*¦transaction,thisvariablecontainsthe&*¦physicalmemoryaddressofthefirst(*¦locationoftheI/Obuffer.‚Attheend&*¦oftheI/Otransferwesubtractthis&*¦variablefromthefinalvalueofthe)*¦bufferpointer(IOBUFPTR,seebelow)to(*¦determinehowmanybyteswereactually*¦transferred. %*¨Foraformatcommandoraconfigure#*¦command,thisvariablecontainsa%*¦garbagevalue.‚However,itsgarbage&*¦valueisthesamegarbagevaluethat%*¦appearsinIOBUFPTRforaformator(*¦configurecommand,sowecorrectlyget&*¦zeroasthecountofdatabytesthat'*¦weretransferredforaformatcommand*¦oraconfigurecommand. 1IOBUFPTRDS.L…1–Forareadtransactionorawrite)*¦transaction,thisvariablecontainsthe)*¦physicaladdressofthenextbytetobe(*¦accessedintheI/Obuffer.‚Attheend%*¦ofanI/Otransfer,therefore,this'*¦variablepointstothebytefollowing)*¦thelastbytethatwastransferred,and(*¦wecansubtractIOBUFLOCfromIOBUFPTR'*¦todeterminethelengthoftheactual*¦I/Otransfer. %*¨Foraformatcommandoraconfigure#*¦command,thisvariablecontainsa%*¦garbagevalue.‚However,itsgarbage&*¦valueisthesamegarbagevaluethat%*¦appearsinIOBUFLOCforaformator(*¦configurecommand,sowecorrectlyget&*¦zeroasthecountofdatabytesthat"*¦weretransferredforaformator*¦configurecommand.-‰PAGEš#######################################?*ˆThesevariablesareacontinuationofthedrive'sI/Opacket. 1IOBUFTCBDS.L…1–Forareadtransactionorawrite)*¦transaction,thisvariablecontainsthe%*¦physicaladdressoftheTCBforthe&*¦taskthatownstheI/Obuffer.‚Fora(*¦formatcommandoraconfigurecommand,%*¦thisvariablecontainsthephysical&*¦addressoftheTCBforthetaskthat&*¦ownstheIOCB.‚Theinterrupthandler)*¦needsthisvariablesoitcandecrement)*¦thetask'sTCBIOCNTwhentheI/Otrans-*¦actioniscompleted. 0DCBPNTR‚DS.L…1–Thisvariablealwayscontainsthe&*¦physicaladdressofthediscdrive's'*¦DCB.‚Theinterrupthandlerneedsthis$*¦variablesoitcanincludetheDCB'*¦addressaspartoftheI/Ocompletion(*¦eventthattheinterrupthandlersends#*¦totheattachedtaskwhentheI/O!*¦transactionhasbeencompleted. 0IOCBPTR‚DS.L…1–Thisvariablealwayscontainsthe&*¦physicaladdressoftheIOCBforthe'*¦commandthatrequestedtheI/Otrans-%*¦action.‚Theinterrupthandlerneeds(*¦thisvariablesoitcansettheIOSSTA(*¦fieldandtheIOSLENf ieldoftheIOCB#*¦whentheI/Otransactionhasbeen*¦completed.-‰PAGEš#######################################?*ˆThesevariablesareacontinuationofthedrive'sI/Opacket. 4EOVFLAG‚DS.B…1–Thecommandserviceroutinesetsthis)*¦flagequaltotheISTAOKstatuscodeif'*¦therequestedI/Otransferdoesn'tgo$*¦beyondtheendofthedisc.‚Ifthe'*¦requestedI/Otransferdoesgobeyond#*¦theendofthedisc,however,the(*¦commandserviceroutinesetsthisflag&*¦equaltotheISTAEOV(end-of-volume)(*¦statuscode.‚Inthiscase,thecommand'*¦serviceroutineadjuststhelimitsof'*¦therequestedI/Otransfertomakeit#*¦terminateattheendofthedisc. %*¨Ifwedon'tencounteranyerrorsin)*¦theactualperformanceoftherequested)*¦I/Otransfer,wereturnthecodeinthe)*¦EOVFLAGvariableasthestatuscodefor&*¦theI/Otransaction.‚Anyothererror&*¦thereforeoverridesanend-of-volume'*¦error,andwereportanend-of-volume&*¦erroronlyifwedon'tencounterany*¦othererrors. 2CTRLCODEDS.B…1–Thisvariablecontainsthecontrol(*¦codethatwillbeusedinthecontrol-(*¦codefieldoftheSASIcommandpacket.'*¦Foraconfigurecommand,thecontrol-)*¦codevalueisusedtodefinetheformat&*¦thatisbeingspecifiedforafloppy(*¦disc.‚Bit0ofthecontrolcodecanbe&*¦settospecifyadouble-sidedfloppy)*¦disc,andbit1ofthecontrolcodecan$*¦besettospecifyadouble-density*¦floppydisc. ECTRLDFLTEQU†0<*„|ƒ|ƒ|ƒ|„|ƒ|ƒ--------1=Controllerrequestingoutputdata.{*„|ƒ|ƒ|ƒ|„|ƒ|²{?*„|ƒ|ƒ|ƒ|„|ƒ------------1=Controllerhasinputdataready.‚{ *„|ƒ|ƒ|ƒ|„|¶{B*„|ƒ|ƒ|ƒ|„----------------1=Controllerhasstatusbyteready.{*„|ƒ|ƒ|ƒ|»{D*„|ƒ|ƒ|ƒ---------------------1=Controllerrequestinginterrupt.‚{ *„|ƒ|ƒ|¿{+*„|ƒ|ƒ-------------------------…Notused.™{*„|ƒ|Ã{-*„|ƒ-----------------------------…Notused.™{*„|Ç{>*„---------------------------------1=Controllerselected.Ž{ 2BITCMDƒEQU†0–Bit0oftheFLAGSregisterissetif;REQCMDƒEQU†1<*„---------------------------------1=Blockaddressvalid.Ž{ 8ERRBITS‚EQU†%00111111ŽThislabeldefinesabitmaskthat&*¦coverstheerror-codeanderror-type$*¦bitsinthefirsterror-sensedata*¦byte. 7*„7ƒ6ƒ5ƒ4ƒ3ƒ2ƒ1ƒ0‡Theformatfortheotherthreeerror-J*‚+---+---+---+---+---+---+---+---+ƒsensedatabytesisillustratedinthe.*‚|„LUN„|“|ƒdiagramattheleft.‚Thetopthree8*‚|---+---+---+‘--|ƒbitsofbyteonecontainthelogical5*‚|Logical‹|ƒunitnumber,whichisequivalenttothe5*‚|--‹SectorŠ--|ƒchanneldevicenumber.‚TheLUNfield3*‚|NumberŒ|ƒdefinesthelogicalunitnumberoftheI*‚+---+---+---+---+---+---+---+---+ƒdiscthatwasbeingaccessedwhenthe*¦erroroccurred. $*¨Theremainingbitsofbyteoneand(*¦allofbytestwoandthreecontainthe$*¦logicalsectornumber(LSN)ofthe)*¦logicalsector(ifany)thatrelatesto*¦theerror. ‰INCLUDEƒCOMCMD.AI‰INCLUDEƒM420INT.AI‰TTL‡M420DRV.SA‰ENDé‰IFEQ†DTYPE‰TTL‡INTERRUPTHANDLER O*******************************************************************************O*******************************************************************************O*********************************************************************************ˆSASIINTERRUPTHANDLER*E*ˆControlcancometotheSASIinterrupt‚handlerwhenCMRreceivesanG*ˆinterruptontheinterruptlevelthatisusedbytheSASIcontroller.B*ˆIfthe‚interruptisa‚SASIinterrupt,the‚SASI‚interrupthandlerF*ˆsetstheCbitoftheSR,andlowerstheinterruptmasklevelbyone*ˆleveluponreturn.*D*ˆEntry:„A1=physicaladdressoftheSASIinterrupthandlerroutine"*’A5=physicaladdressoftheCCB1*’SR=MaskedattheleveloftheSASIinterrupt.*O*******************************************************************************O*******************************************************************************O******************************************************************************* -‰PAGEš#######################################O******************************************************************************** *ˆSASIINTERRUPTPOLLINGROUTINE*%*ˆEntry:„A5=physicaladdressofCCB*<*ˆExit:…ReturntoCMRviaRTSifitISNOTaSASIinterrupt.4*’FallthroughtoSASIINTifitISaSASIinterrupt.*O******************************************************************************* *¨Time >INTERUPTMOVE.LƒCCBCHB(A5),A0ˆ16(4/0)‡PointA0‚totheMVME4201‰MOVEQ„#REQINT,D0Œ4(1/0)…memory-mappedƒI/O‚area,4‰AND.B„FLAGS(A0),D0Š8(2/0)…and‚checktheSASI‚FLAGS0‰BNE.S„SASIINT8(1/0)…register‚toseeifaSASI&‰RTS›16(3/0)…interruptispending.ƒIf$*¦--------…there‚isn'taSASIinter-$*¦52(11/0)…ruptpending,‚returnwith*³SR.C=0‚toindicatethat*³theinterrupt‚isn'tours.*³TheAND‚instructionauto-*³maticallyclearsthe‚SR.C *³bitforus. $*¨Ifwe'reusinganEXORmacssystem,%*¦thetimeforthepollingroutineisfm4v7~9†8Ž6–1ž8¦3®A¶C¾0Æ2Î/Ö4Þ5æ5î2ö5þ43<02&7.<6>>:F9N3V<*¦computedasfollows. &*¦Time=52+11*3+0*1=85cycles„{*«=85*(0.125)microsecondsˆ{*«=10.625microseconds. #*¨TheEXORmacstypicallyrequires3)*¦waitcyclesforareadcycleand1wait)*¦cycleforawritecycle,andthemicro-'*¦processorinastandardEXORmacsruns&*¦at8.0megahertzforacycletimeof*¦0.125microseconds. %*¨NoticethatthelabelINTERUPTthat)*¦weusehereisintentionallymisspelled"*¦soitwon'texceed8characters. -‰PAGEš##############$ #########################O********************************************************************************#*ˆSASIINTERRUPTCO-ROUTINELINKAGE*C*ˆControlreachesthispointwhenwe'vesuccessfullyidentifiedtheA*ˆinterruptasa‚SASIinterrupt.‚ThisroutineisalsocalledasaB*ˆsubroutinewhenthe‚command-processingroutinewantstoactivateB*ˆinterruptprocessing.‚WhenevertheinterrupthandleremptiestheB*ˆI/Oqueue,wedeactivateinterruptprocessing.‚Whenthecommand-B*ˆprocessingroutine‚putsanewqueueentryintoaemptyqueue,it5*ˆmustcallSASIINTtoactivateinterruptprocessing.*=*ˆEntry:„A0=physicaladdressofSASIMemory-MappedI/Oarea*’A5=physicaladdressofCCB*!*ˆRegisterusage:…01234567 *™D‚*PP *™A‚P*ƒPPP*"*ˆExit:…Jumptoco-routinesegment*O******************************************************************************* 2SASIINT‚EQU†*–WeknowwehaveaSASIinterrupt,so>L0420„EQU†DSABLINT+LEDOFF†disabletheinterruptattheMVME420?‰MOVE.Bƒ#L0420,CONTROL(A0)ƒSASIPeripheralAdapter.‚Thenenable<‰MOVE.WƒCCBSR(A5),SR‰68000interruptsatourinterruptlevel'*¦sothatotherinterruptsatourlevel'*¦won'tbedelayedwhileweprocessour$*¦interrupt.‚Everyinterrupthandler)*¦shouldmaskitsinterruptatthesource)*¦oftheinterruptandthenquicklylower(*¦thesysteminterruptmaskbyonelevel)*¦toallowthesystemtorespondtoother#*¦interruptsthatoccuratthesame*¦prioritylevel. @L0430„REG†A4/A3/A2/D3/D2/D1†A5,A1,A0,andD0havealreadybeen;‰MOVEM.L‚L0430,-(SP)ŠsavedbyCMR.‚Herewesavetherestof'*¦theregistersthatweneedtouse.‚We(*¦saveonlytheregistersthatwereally%*¦needbecausewedon'twanttowaste(*¦timeorstackspace.‚Time,especially,'*¦isimportantinaninterrupthandler. <‰MOVE.LƒIOQUEUE(A5),A1‰SetA1=LOC(Drive'svariableblock).)*¦ThefirstentryoftheIOQUEUEcontains)*¦apointertothevariableblockforthe)*¦discdrivethatweshouldbeaccessing. =‰MOVE.LƒINTSWTCH(A5),A3ˆBranchtotheco-routinesegmentthat"‰JMP†(A3)‘shouldbeexecutednext. %*¨Controlwilleventuallyreturnfrom(*¦theselectedco-routinesegmenttothe&*¦INTRTNroutine,whichimplementsthe*¦returnlinkagetothesystem. -‰PAGEš#######################################O*********************************************************************************ˆSASIOPCODETABLE*@*ˆThistable‚containsthe‚SASI-definedopcode‚valuesfortheI/OD*ˆoperationsthatwecurrentlyusewiththeSA1403DSASIcontroller.*O******************************************************************************* 2*’---------------------------SASIOpcodevalue.Œ{*’|¹{!*’|”------IOFUNCTindexvalue.Š{*’|”|¤{*’|”|¤{*’V”V¤{‰DC.B…$0A’-1=Writedisc.–{!OPTBL„DC.B…$04“0=Formatdisc.•{/‰DC.B…$C0’+1=Defineformatforfloppydisc.ƒ{‰DC.B…$08’+2=Readdisc.—{ 5FTRACKƒDC.B…$06”Theopcodeforaformat-trackcommand)*¦isnotindexedbytheIOFUNCTvaluefor%*¦aformat-trackcommand.‚Theformat-$*¦trackcommandhasthesameIOFUNCT&*¦valuethatisusedforaformat-disc'*¦command,andweuniquelyidentifythe'*¦format-trackcommandbythefactthat(*¦itsIOOPTSvalueisdifferentfromthe)*¦IOOPTSvaluethatisusedforaformat-(*¦disccommand.‚Thenwecomputeapseudo'*¦IOFUNCTvaluethatindexesfromOPTBL*¦toFTRACK. '‰DS.W…0–Thisstatementensuresthatthe'*¦locationcounterisalignedtoaword*¦boundary.-‰PAGEš#######################################3SENSECMDEQU†$03”ThislabeldefinestheSASIopcode(*¦valueforarequest-sensecommand.‚The$*¦SASIdriverissuesarequest-sense&*¦commandwhenevertheSASIcontroller'*¦returnsastatusvaluethatindicates$*¦anerror.‚Thecontrollerreturnsa&*¦statusvalueattheendofeveryI/O(*¦transaction,andthedriverchecksthe%*¦statusvaluetoseeifanerrorhas(*¦occurred.‚Ifanerrorhasoccurred,we)*¦issuearequest-sensecomman$ dtoobtain'*¦detailedinformationabouttheerror. "*¨Auser'sprogramcannotdirectly&*¦generatearequest-sensecommand,so(*¦theopcodevaluefortherequest-sense)*¦commandisn'tintheSASIopcodetable.&*¦TheSASIdriverautomaticallyissues)*¦request-sensecommandsasnecessaryfor*¦erroranalysis. -‰PAGEš#######################################O*********************************************************************************ˆPROCESSNEXTQUEUEENTRY*E*ˆControlcomestothisco-routinesegmenttoprocessthefrontentryD*ˆoftheIOQUEUE.‚Weareguaranteedthatthequeueinnon-emptywhen *ˆcontrolcomestothisroutine.*=*ˆEntry:„A0=physicaladdressofSASIMemory-MappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*!*ˆRegisterusage:…01234567 *™D‚*** *™A‚PPƒ**P*9*ˆExitsto:‚SendacommandpackettotheSASIcontroller.*O******************************************************************************* =PROCQUE‚LEA†CMDEND(A5),A3ŠWewanttoexaminethevariablesin(*¦thedrive'sI/Opacket,andwewantto'*¦constructacommandpacketforaSASI)*¦commandthatwillimplementpartorall&*¦ofthefunctionthatisspecifiedin$*¦thedrive'sI/Opacket.‚Thenwe'll)*¦transmitthecommandpackettotheSASI *¦controller. %*¨WestartbypointingA3tothebyte(*¦thatimmediatelyfollowsthelastbyte(*¦ofthecommandpacketinmemory.‚We'll(*¦useautodecrementaddressingtoaccess*¦thecommandpacket.-‰PAGEš####################################### /***********************************************-*MODFORDTC520ASASICONTROLLER11/16/83ƒ**(* Modified for both controllers 12/12/83*/***********************************************(‰CMP.B…#1,IOFUNCT(A1)†TESTFORCONFIGURE!‰BNE.S…PROQ1BRAIFNOTCONFIGURE-‰BTSTW…#IOASIZE,CONFGBLK+IOSATW(A1)‚8"DRIVE?‰BNE.S…PROQ1BRAIF8"DRIVE6‰LEA‡DTCCMD(A5),A3‡POINTTOCONFIGUREDRIVECMD.PCKT.‰BRA.S…L0490AŽGOSENDDATA/************************************************ENDOFMOD—11/17/83ƒ*/*********************************************** ‰PAGEDPROQ1„MOVE.BƒCTRLCODE(A1),-(A3)…Copythecontrol-codevaluefromthe2L1‡SET†CMDCTRLŽdrive'sI/OpacketintotheCMDCTRL%*¦fieldofthecommandpacket.‚Notice'*¦theuseoftheSETpseudoinstruction)*¦togenerateaconcordanceentryforthe&*¦CMDCTRLfieldthatismodifiedhere. ;‰MOVE.LƒIOSCTCNT(A1),D0ˆNowusetheIOSCTCNTvaluefromthe<‰MOVE.Lƒ#MAXSECTS,D1‰drive'sI/OpackettofilltheCMDSECTS0‰CMP.L„D1,D0fieldofthecommandpacket.‚Ifthe3‰BLS.S„L0470countofremainingsectorsexceedsthe3‰MOVE.LƒD1,D0maximumnumberofsectorsthatcanbe>16,(A3)+ƒdiscdrive'sI/Opackettosetupthe;‰MOVE.BƒDRIVENUM(A1),D1†logicalsectornumberintheCMDLSN8‰LSL.B„#LUNFIELD,D1‰fieldofthecommandpacket.‚Wealso6‰OR.B…D1,-(A3)usetheDRIVENUMvaluefromthedrive's1L1‡SET†CMDLSNI/OpackettosettheLUN(Logical-#*¦Unit-Number)fieldinthecommand&*¦packet.‚NoticethattheLUNfieldin)*¦thecommandpacket% occupiesthetopfew&*¦bitsofthefirstbyteoftheCMDLSN%*¦(Logical-Sector-Number)field.‚Also'*¦noticetheuseoftheSETinstruction)*¦togenerateaconcordanceentryforthe*¦CMDLSNfield.-‰PAGEš#######################################9‰ADD.L„D0,IOSECTOR(A1)ˆIncreasetheIOSECTORvalueinthe%*¦drive'sI/Opacketbythenumberof%*¦sectorsthatwillbeprocessedasa%*¦resultofthiscommandpacket.‚This(*¦adjustmentcausesIOSECTORtopointto)*¦thesectorthatshouldbespecifiedfor(*¦thenext(ifany)commandpacketafter*¦thisone. ;‰MOVE.BƒIOFUNCT(A1),D0‰GettheIOFUNCTcodeintoD0.Wsowe+‰EXT.W„D0“canuseittoindexintotheSASI1‰BNE.S„L0490opcodetable.‚IftheIOFUNCTcodeis(*¦nonzero,wearen'tprocessingaformat'*¦command.‚Inthiscase,wecanusethe&*¦IOFUNCTvaluedirectly.‚Foraformat#*¦command,however,wemustdosome*¦specialprocessing. >L0480„EQU†CONFGBLK+IOSILVˆForaformatcommandwemustinstall@‰MOVE.BƒL0480(A1),CMDILV(A5)aninterleavevalueintotheCMDILV$*¦field,whichoverlaystheCMDSECTS'*¦fieldofthecommandpacket.‚Thereis'*¦nosectorcountforaformatcommand,'*¦butthecontrollerrequiresaninter-%*¦leavecodeinplaceoftheCMDSECTS*¦fieldforaformatcommand. :‰BTSTW„#IOPTRKB,IOOPTS(A1)„IftheIOOPTSvalueinthedisc4‰BEQ.S„L0490drive'sI/Opacketindicatesthatwe're:‰MOVEQWƒFTRACK-OPTBL,D0†processingaformat-trackcommand,'*¦adjustD0.Wtoindextheformat-track!*¦entryoftheSASIopcodetable.%*¦Otherwise,D0.Walreadyindexesthe&*¦format-discentryoftheSASIopcode*¦table. #*¨WeuseasingleIOFUNCTvaluefor&*¦boththeformat-disccommandandthe&*¦format-trackcommand.‚Wedistinguish)*¦onecommandfromtheotherbyexamining*¦theirIOOPTSvalues. FL0490„MOVE.BƒOPTBL(PC,D0.W),-(A3)ƒFinally,filltheCMDOPfieldofthe4L1‡SET†CMDOPcommandpacketfromtheproperentryof'*¦theSASIopcodetable.‚NoticethatA3&*¦nowpointstotheCMDOPfieldofthe'*¦commandpacket,sowecanuseA3with)*¦autoincrementaddressingaswesendthe(*¦commandpackettotheSASIcontroller.'*¦AlsonoticetheuseoftheSETpseudo'*¦instructiontogenerateaconcordance*¦entryfortheCMDOPfield.-‰PAGEš#######################################6L0490AƒBSR†SENDCMDSendthecommandpackettotheSASI&*¦controllertotellthecontrollerto&*¦startprocessing.‚SubroutineSENDCMD'*¦usesA3withautoincrementaddressing(*¦tosendthecommandpackettotheSASI)*¦controller,andsubroutineSENDCMDalso'*¦assumesthatA0pointstothememory-)*¦mappedI/OareafortheSASIperipheral *¦adapter. O*********************************************************************************ˆREADORWRITENEXTSECTOR*B*ˆControl‚comestothetopofthis‚co-routinewhentheSASIdriverD*ˆisreadytoreadorwritethedataforthenextsectorthatshould@*ˆbetransferred.‚Controlalso‚comestothis‚routine‚immediately=*ˆafter‚anycommand‚sequence‚hasbeen‚transmitted‚to‚the‚SASI *ˆcontroller.*=*ˆEntry:„A0=physicaladdressofSASIMemory-MappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*!*ˆRegisterusage:…01234567 *™D‚*** *™A‚PPƒ**P*1*ˆExitsto:‚Branchestointerruptreturnroutine.*O******************************************************************************* 8NEXTSECTBSR†INTRTN‘TheSASIcontrollerneedstimetodo$*¦itsjobbeforewecantransferany(*¦data,soreturncontroltothesystem.'*¦WhentheSASIcontrollerhasfinished$*¦itscurrenttask,we'llreceivean&*¦interruptthatwillcausecontrolto(*¦comebackhere.‚Theco-routinelinkage)*¦convenientlyallowsustocalltherest&*¦ofthesystemasifitweresimplya)*¦subroutinetobeexecutedwhilewehave*¦nothingbettertodo. *Â(Continued)-‰PAGEš########################################*¨Ifwe'vejusttransmittedawrite%*¦commandtotheSASIcontroller,the'*¦inte% rruptshouldoccurquickly(since(*¦thecontrollershouldsoonbereadyto'*¦copyasectorofoutputdataintoits$*¦databuffer).‚However,experiments&*¦haveshownthatthecontrollerneeds'*¦enoughtimeeveninthiscasetomake(*¦itworthwhileforustoreturncontrol*¦tothesystem. %*¨Ifwe'vejusttransmittedareador'*¦formatcommandtothecontroller,the%*¦controllerwillobviouslyrequirea&*¦substantialamountoftimebeforeit*¦interruptsthesystemagain. 9L0530„EQU†CONFGBLK+IOSPSMˆControlreachesthisco-routine;‰MOVE.WƒL0530(A1),D1‰segmentwhenthecontrollerinterrupts(*¦toindicatethatit'sreadytoproceed'*¦withtheI/Ooperation.‚WegetIOSPSM&*¦intoD1.W,soD1.Wnowindicatesthe!*¦logicalsectorsize(inbytes). 9‰TST.B„HALFSCTS(A1)‹Ifthenextsectortobeprocessedis2‰BEQ.S„L0535ahalfsector,dividethesectorsize2‰LSR.W„#1,D1bytwotoaccountforthefactthata>‰SUB.B„#1,HALFSCTS(A1)†halfsectorhasonlyhalfasmanybytes(*¦asanormalsector.‚Thendecrementthe(*¦countofthehalfsectorsremainingto%*¦beprocessed.‚Halfsectorsarisein'*¦trackzeroofadouble-densityfloppy(*¦discbecausethesectorsintrackzero%*¦ofadouble-densityfloppydiscare*¦recordedwithsingledensity.-‰PAGEš#######################################‰MOVEP.L‚DATA0(A0),D0†|‚thememorymap.‚Therefore,theMOVEP.L5‰MOVE.LƒD0,(A3)+Š|‚instructionaccessesthesamedata(*§|‚registerfourconsecutivetimeswith/‰DBRA…D3,L0550Š----‚themaximumpossiblespeed. #*¨IftheSASIcontrollerhappensto$*¦sufferfromacatastrophicfailure)*¦duringthisloop,we'llgetabuserror*¦toindicatetheproblem. 4‰DBRA…D1,READDATAŒIfwehaven'tfinishedreadingthe&*¦currentsectorofdata,loopbackto(*¦readthenextchunkofLCDSCTSZbytes.$*¦ByreadingLCDSCTSZbytesandthen)*¦checkingthecontroller,wecanprevent&*¦thecarelessuserfromcausingabus*¦error. 0‰BRA.S„RWCOMMONWe'vefinishedreadinganentire(*¦sectorofinputdata,sonowgotothe#*¦commonroutinethatcompletesthe&*¦processingofasectorforbothread"*¦operationsandwriteoperations. -‰PAGEš#######################################O*********************************************************************************ˆWRITEASECTOROFDATA*O******************************************************************************* GWRTDATA‚MOVEQBƒSELECTED+REQWRITE,D3ƒWe'reperformingawriteoperation,4‰BSR†CHKFLAGSsochecktheSASIcontrollertoverify)*¦thatthecontrollerisreadytoreceive'*¦outputdata.‚SubroutineCHKFLAGSsets)*¦theCC.Zbitifthecontrollerisready&*¦fortheoperationindicatedinD3.B.-‰PAGEš#######################################>L0560„SNE.B„NOFINISH(A1)‹Ifthecontrollerisn'treadyforthe7‰BNE.S„READSTATproperoperation,settheNOFINISHflag%*¦andgotrytoreadthecontroller's$*¦statusreport.‚WeusetheNOFINISH'*¦flagtoindicatethatareadorwrite$*¦I/Ooperationhasfailedtofinish$*¦correctlyforsomeunknownreason. &*¨Controlcomesthroughthissamecode$*¦segmentifthecontrollerfailsto'*¦becomereadyfortheproperoperation*¦duringareadtransaction. .L0561„EQU†4*8”Eachiterationoftheinnerloop=L0562„EQU†LCDSCTSZ/L0561‡belowtransfers4*8=32databytes,=L0563„EQU†L0562*L0561Šandeachiterationoftheouterloopis9‰IFNE…LCDSCTSZ-L0563‡supposedtotransferLCDSCTSZbytes./‰FAIL…0”[****ERROR****ERROR****ERROR****]+‰ENDCšTherefore,wemustverifythat4*8is#*¦anexactdivisorofLCDSCTSZ.‚The#*¦instructionthatisconditionally&*¦assembledheregeneratesanassembly)*¦errorif4*8isnotanexactdivisorof%*¦LCDSCTSZ.‚Ifthiserroroccurs,the(*¦maintenanceprogrammerwillbealerted(*¦tochangetheinnerloopbelowtomake(*¦ittransfersomeothernumberofbytes)*¦sothatasingleiterationoftheouter#*¦loopcantransferLCDSCTSZbytes. @‰MOVEQWƒLCDSCTSZ/L0561-1,D3„InitializeD3.Wtocontroltheinner'*¦loop.‚We'llperformenoughiterations(*¦oftheinnerlooptotransferLCDSCTSZ*¦bytesofdata.-‰PAGEš#######################################?L0570„MOVE.Lƒ(A3)+,D0Š----‚Eachcompleteiterationofthisloop>‰MOVEP.L‚D0,DATA0(A0)†|‚transfers4*8=32databytesfromthe(*§|‚outputbuffertotheSASIcontroller8‰MOVE.Lƒ(A3)+,D0Š|‚andweperformjustenoughiterations>‰MOVEP.L‚D0,DATA0(A0)†|‚ofthisinnerlooptotransferatotal *§|‚ofLCDSCTSZbytesduringone1‰MOVE.Lƒ(A3)+,D0Š|‚iterationoftheouterloop.‹{‰MOVEP.L‚D0,DATA0(A0)†|©{#*§|„WeuseaMOVEP.Linstructionto7‰MOVE.Lƒ(A3)+,D0Š|‚transferfourconsecutivedatabytes?‰MOVEP.L‚D0,DATA0(A0)†|‚withthemaximumpossiblespeed,andwe&*§|‚replicatethecodeinthisloopto7‰MOVE.Lƒ(A3)+,D0Š|‚reducetheeffectsofloopoverhead.;‰MOVEP.L‚D0,DATA0(A0)†|‚Wecouldreplicatethecodeinthis'*§|‚loopmoretimesforevenmorespeed8‰MOVE.Lƒ(A3)+,D0Š|‚butdiminishingreturnsbegintomake?‰MOVEP.L‚D0,DATA0(A0)†|‚furtherreplicationslessattractive.{*§|¤{8‰MOVE.Lƒ(A3)+,' D0Š|„TheSASIcontrolleractuallyhasjust<‰MOVEP.L‚D0,DATA0(A0)†|‚onedataregister,butthatregister'*§|‚appearsat4differentlocationsin9‰MOVE.Lƒ(A3)+,D0Š|‚thememorymap.‚Therefore,theMOVEP.L:‰MOVEP.L‚D0,DATA0(A0)†|‚instructionaccessesthesamedata%*§|‚register4consecutivetimeswith/‰DBRA…D3,L0570Š----themaximumpossiblespeed. #*¨IftheSASIcontrollerhappensto$*¦sufferfromacatastrophicfailure)*¦duringthisloop,we'llgetabuserror*¦toindicatetheproblem. 3‰DBRA…D1,WRTDATAIfwehaven'tfinishedwritingthe&*¦currentsectorofdata,loopbackto)*¦writethenextchunkofLCDSCTSZbytes.$*¦BywritingLCDSCTSZbytesandthen)*¦checkingthecontroller,wecanprevent&*¦thecarelessuserfromcausingabus*¦error. &*¨We'vefinishedtransferringasector&*¦ofoutputdata,sonowcontrolfalls(*¦intothecommonroutinethatcompletes%*¦theprocessingofasectorforboth'*¦readoperationsandwriteoperations. -‰PAGEš#######################################O********************************************************************************#*ˆCOMPLETEPROCESSINGOFREAD/WRITE*#*ˆEnteredfrom:READDATAorWRTDATA**ˆExitsto:*O******************************************************************************* @RWCOMMONMOVE.LƒA3,IOBUFPTR(A1)ˆUpdatetheI/Obufferpointerto#*¦pointtothenextbyteoftheI/O&*¦buffer.‚Ifthere'sanothersectorof'*¦datatobetransferred,IOBUFPTRwill'*¦beusedtoaddresstheI/Obuffer.‚If'*¦thereisn'tanothersectorofdatato'*¦betransferred,we'lluseIOBUFPTRto)*¦calculatethenumberofbytesthatwere*¦actuallytransferred. :‰SUB.B„#1,CMDSECTS(A5)ˆDecrementthecountofsectorsthat4‰BHI†NEXTSECTremaintobeprocessedforthecurrent&*¦SASIcommandsequence.‚Ifwehaven't(*¦finishedprocessingallofthesectors(*¦forthecurrentSASIcommandsequence,'*¦loopbacktoprocessthenextsector. .‰TST.B„D2•We'vefinishedprocessingallofthe5‰BGT.S„RDSTAT1Žsector(s)forthecurrentSASIcommand&*¦sequence.‚Ifwe'reperformingaread%*¦operation,goreadthecontroller's&*¦statusreport.‚Thecontrollershould#*¦havethestatusreportforaread$*¦operationreadyalmostimmediately(*¦afterthelastsectorofdatahasbeen%*¦read,sothere'snoadvantagetobe$*¦gainedbyreturningcontroltothe(*¦systemtowaitforastatus-readySASI(*¦interrupt.‚RecallthatD2.B=+1fora)*¦readtransactionandthatD2.B=-1for*¦awritetransaction. $*¨Ifwe'reperformingawriteopera-)*¦tion,fallintothetopoftheREADSTAT%*¦routine.‚Controlwillreturntothe)*¦system,andwe'llgetcontrolbackwhen&*¦astatus-readyinterruptoccurs.‚The'*¦controllerwillrequireasignificant)*¦amountoftimebeforeithasitsstatus%*¦reportreadybecauseitmustdothe(*¦physicalwritingofthelastsectorof'*¦databeforeitcanprepareitsstatus *¦report. -‰PAGEš#######################################O********************************************************************************!*ˆREADTHESASICONTROLLERSTATUS*O******************************************************************************* 7READSTATBSR.S„INTRTN‘Returncontroltothesystem,and)*¦waitforastatus-readySASIinterrupt.&*¦We'llgetcontrolbackwhentheSASI)*¦controllerhasitsstatusreportready. 5RDSTAT1‚BSR†GETSTATGetthestatusbitsfromtheSASI6‰BNE.S„STATERRŽcontroller'sstatusbyteintoD0.B,and(*¦reportanerrorifthestatusbitsare&*¦nonzero.‚Astatusbitthatissetin(*¦thecontroller'sstatusbyteindicates&*¦anerror.‚SubroutineGETSTATreturns$*¦theconditioncodesreflectingthe(*¦statusbitsfromtheSASIcontroller's*¦statusbyte.-‰PAGEš#######################################6‰MOVEQBƒISTACFG,D1IftheNOFINISHflagisnonzero,we8‰TST.B„NOFINISH(A1)‰returnastatuscodeindicatingthat4‰BNE.S„SASIDONEtheactualconfi' gurationofthedisc(*¦doesn'tmatchtheconfigurationinthe%*¦currentconfigurationblock.‚AnI/O)*¦operationfailedtofinishproperly,so&*¦thesectorsizeonthediscprobably&*¦doesn'tmatchthesectorsizeinthe*¦configurationblock. 8‰TST.L„IOSCTCNT(A1)‹TheSASIcontrollerhassuccessfully1‰BNE†PROCQUEŽcompletedtheentireI/Otransaction(*¦thatwasspecifiedbythelastcommand(*¦sequencethatwegaveit.‚Ifthereare'*¦anysectorsremainingtobeprocessed)*¦forthecurrententryoftheI/Oqueue,'*¦loopbacktoprocessanotherchunkof*¦theentireI/Otransfer. %*¨RecallthatIOSCTCNTisalwayszero&*¦foranyI/Otransactionthatdoesn't(*¦involvethetransferofanyread/write*¦data. 9‰MOVE.BƒEOVFLAG(A1),D1‰We'venowcompletedtheentireI/O'*¦transactionthatwasspecifiedbythe$*¦commandthatgeneratedthecurrent%*¦entryoftheI/Oqueue.‚TheEOVFLAG'*¦valuethatwegetintoD1.Bherewill#*¦bereturnedtotheuserasanI/O&*¦statuscode.‚IftheI/Otransferwas'*¦truncatedtoavoidrunningbeyondthe(*¦endofthedisc,wereturntheISTAEOV'*¦statuscode.‚Otherwise,wereturnthe)*¦ISTAOKstatuscodetoindicatethatthe!*¦entireoperationwentsmoothly. %*¨ControlnowfallsintotheSASIDONE"*¦routinetofinishprocessingthe!*¦currententryoftheI/Oqueue. -‰PAGEš#######################################O*********************************************************************************ˆFINISHPROCESSINGQUEUEENTRY*B*ˆControlcomes‚tothetop‚ofthis‚co-routinewhentheSASIdriverC*ˆisreadytofinish‚processing‚thecurrententryofthe‚I/Oqueue.E*ˆEitherwe'vecompletedtheI/OtransactionthatisspecifiedbytheC*ˆcurrentwntryofthe‚queue,orelsewe've‚runintosomeunreason-G*ˆableproblemthatwecan'tsolve.We'llqueueanI/OcompletioneventC*ˆtotheattachedtask,andwe'll‚removethe‚currententryfromtheD*ˆI/Oqueue.‚IftheI/Oqueuehasanotherentry,we'llloopbackand*ˆstartprocessingit.*=*ˆEntry:„A0=physicaladdressofSASIMemory-MappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*D1.B=statusvalue*!*ˆRegisterusage:…01234567 *™D‚*** *™A‚PPƒ**P*3*ˆExitsto:‚IDLELOOProutineifI/Oqueueisempty.4*“PROCQUEiftheI/Oqueuecontainsanactiveentry.*O******************************************************************************* 3SASIDONEEQU†*–WeuseaMOVEM.Linstructiontopull=L0630„REG†D0/D2/A1/A3/A4‡severalvariablesoutofthecurrentA‰MOVEM.L‚IOBUFLOC(A1),L0630ƒI/Opacketinonestep.‚Thisinstruc-(*¦tionsetsuptheregistersasfollows. L1‡SET†IOBUFLOCD0=IOBUFLOC.L1‡SET†IOBUFPTRD2=IOBUFPTR.L1‡SET†IOBUFTCBA1=IOBUFTCB.5L1‡SET†DCBPNTRŽA3=DCBPNTR.‚(ForsubroutineQEVENTI)5L1‡SET†IOCBPTRŽA4=IOCBPTR.‚(ForsubroutineQEVENTI) $*¨TheSETinstructionsthatareused'*¦herearejustdummyinstructionsthat&*¦generateartificiallabelreferences%*¦fortheconcordancelisting.‚Future)*¦maintenanceprogrammerswillbeableto)*¦usetheconcordancelistingtodiscover$*¦thatthissegmentofcodeaccesses*¦thesevariables.-‰PAGEš#######################################1‰SUB.L„D0,D2’Nowcomputethenumberofdatabytes=‰MOVE.LƒD2,IOSLEN(A4)ˆthatweactuallytransferred,andstore&*¦thatnumberintotheIOSLENfieldof%*¦theIOCB.‚ForanI/Ooperationthat%*¦doesn'tinvolvethetransferofany%*¦read/writedata,wehaveIOBUFLOC=)*¦IOBUFPTR,soweproperlysetIOSLEN=0*¦inthiscase. 8‰LEA†ERRDISK(PC),A2‰UsetheVersadoserrorcodetocheck:WHEEL„MOVE.Bƒ(A2)+,D2whethertheIOSRRNfieldoftheIOCB2‰BEQ.S„NOCOPYneedsupdating.Iftheerrorcodeis4‰CMP.B„D2,D1foundinthetableERRDISK,thenupdate3‰BNE.S„WHEELtheIOSRRNfieldintheIOCB.Thelast1‰MOVE.LƒD3,IOSRRN(A4)ˆentryinthetableiszero. 3NOCOPYƒBSR†QEVENTISubroutineQEVENTIqueuesanI/O(*¦completioneve( nttotheattachedtask.)*¦RegistersA5,A4,A3,andD1.Bmustall)*¦besetproperlywhenwecallsubroutine *¦QEVENTI. 9‰SUB.B„#1,TCBIOCNT(A1)ˆDecrementthecountofoutstanding'*¦I/Ooperationsforthetaskthatowns)*¦theI/Obuffer(ortheIOCBinthecase%*¦ofaformatcommandoraconfigure-*¦floppycommand). 6L0640„REG†A1/A3/A4HereweremovethefrontentryfromA‰MOVEM.L‚IOQUEUE+4(A5),L0640‚theI/Oqueue,andwesimultaneouslyA‰MOVEM.L‚L0640,IOQUEUE(A5)„setA1topointtothedriveblockfor(*¦thediscdrivethatisassociatedwith$*¦thenext(ifany)entryoftheI/O%*¦queue.‚Sincethereareamaximumof(*¦fourentriesintheI/Oqueue,weneed'*¦tomovenomorethanthreeentriesto(*¦removethefirstentryfromthequeue. 6‰SUB.W„#4,IOQCNT(A5)ŠReducethequeue-countpointerto1‰BHI†PROCQUEŽaccountforthefactthatwe'vejust(*¦removedafour-byteentryfromtheI/O$*¦queue.‚Ifthereisstillanactive&*¦entryintheI/Oqueue,loopbackto"*¦startprocessingthenextentry. $*¨IftheI/Oqueueisempty,control(*¦fallsintotheco-routinesegmentthat%*¦ispotentiallyactivewhentheSASI'*¦controlleriscaughtupandshouldbe*¦idle. -‰PAGEš#######################################O*********************************************************************************ˆIDLELOOPROUTINE*C*ˆControlfallsintothisco-routine‚segmentwhenthe‚I/OqueuehasD*ˆbeenemptied.‚TheSASIcontrolleriscompletelycaughtupwithall?*ˆofitsrequests,‚andthe‚controller‚should‚nowbe‚idle.‚We'llB*ˆsimplyreturncontroltothe‚systemto‚idlethe‚SASI‚controller.*=*ˆEntry:„A0=physicaladdressofSASIMemory-MappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*!*ˆRegisterusage:…01234567 *™D‚*** *™A‚PPƒ**P*D*ˆExitsto:‚Staysinloopuntilthedriverreceivesanothercommand.*O******************************************************************************* :IDLELOOPBSR.S„INTRTN‘TheI/Oqueueisempty,sowesimply%*¦returncontroltothesystem.‚We've)*¦caughtupwithalloftherequeststhat'*¦havebeensetupforprocessingunder*¦interruptcontrol. *ˆExitsto:‚SASIDONEtoterminateprocessingfortheactivity.*O******************************************************************************* 7CTRLERR1ADDQ.Lƒ#4,SP’Controlcomestothisentrypoint%*¦whenacontrollererrorisdetected%*¦fromwithinasubroutine.‚Weremove&*¦thesubroutine'sreturnaddressfrom(*¦thestack,sothestackisrestoredto&*¦theconditionthatithadbeforethe*¦subroutinewascalled.-‰PAGEš####################################### >CTRLERR‚ST.B…SASIDOWN(A5)‹DowntheSASIchannelbysettingthe"*¦variablethatindicatesthatthe#*¦controllerisdown.‚Ifthesystem(*¦triestoaccesstheSASIchannelagain#*¦withoutresettingitfirst,we'll%*¦reportanerrorindicatingthatthe$*¦channelisdown.‚Thesystemreally"*¦shouldn'ttrytoaccesstheSASI'*¦channelagainwithoutfirstresetting$*¦thecontroller.‚Evenresettingthe)*¦controllermaynotcorrecttheproblem,'*¦butwe'llletthesystemtryasoften*¦asitwishes. 5‰MOVEQBƒISTACNT,D1SetupD1.Bforreportingastatus5‰BRA†SASIDONEcodethatindicatesacontrollererror,%*¦andgoterminateprocessingforthe!*¦currententryoftheI/Oqueue. -‰PAGEš#######################################O******************************************************************************** *ˆCHKFLAGS.AL*O******************************************************************************* GREADRDY‚MOVEQBƒSELECTED+REQREAD,D3„Thisspecialentrypointisusedfor(*¦checkingtheSASIcontrollertoseeif(*¦ithasinputdat+ areadytotransferto(*¦us.‚WegettheproperFLAGSvalueinto'*¦D3.B,andthencontrolfallsdirectly'*¦intothemainentrypointforsubrou-*¦tineCHKFLAGS. -‰PAGEš#######################################:*ˆControlsometimesfallsintothissubroutinefromabove. ‚TIMEFLAG(A5)‚inFINDDENS#*’(shouldhavebeenoffsetfromA5)%*ˆ4/4/84„Newboardwithenhancements:4*’(1)Candisableandenableinterruptsattheboard+*–levelbywritingintotheDSCMDregister.***–Usenewmacros,ENABLMTAandINHIBMTAto'*–turntheboardinterruptoninINTRTN0*–andtoturntheboardinterruptoffwhenabout*–togiveacommand.*1*–ReplaceINHIBwhichmasksallinterruptsatthe1*–wholeinterruptlevelwithINHIBMTA,whichonly"*–affectsinterruptsattheboard.*4*–Theonlyexceptioniswhenwearemessingwiththe-*–IOQUEUEinthecommandhandlerandMTADONE.*–Whyisthat,youask?3*–IhopetofindoutwhytheSASIdoesitthisway.*6*’(2)Afterreadingaharderror,areadofthestatus2*–registerwillcleartheinterruptsothereisno*–needtostopthetape.1*–Fortestingpurposes,fornow,iftheinterrupt1*–doesnotgoaway,inoneread,wewillstopthe*–tapeasbefore.*4*’(3)AninterruptisgeneratedwhenDNBSYgetsset.1*–Bit1intheSTAT2registercannowmeanoneof'*–3things:DNBSY,FNBSY,andfilemark.- ‰>™4¡0©9±=¹pÁMÉ9Ñ8ÙGá;é=ñ;ùFA B7?!9)9199dAIIBQ:YAaAi?qYy@1*–ForaDNBSYwejustcontinueasifnointerrupt*–ofthattypewerereceived.**ˆ4/12/84ƒBugfix:4*’A1wasnotgettingsetupproperlyforabranchto*’PROCQUEfromMTADONE.6*’Nowweputtheaddressofthedrive'svariableblock*’intoA1beforewebranch.*.*’EndoftapehandlingwasnotrightinMTINT.*’EliminatedaBRA‚MTINT3.*.*’Checkforendoftapeonforwardcommandand6*’beginningoftapeonreversacommandwasnotcorrect*’inPROCQUE(STAT1vs.STAT2)*A*ˆ5/4/84„Sometimeswhenablanktapeismountedonthetransport,2*’wedecideerroneouslythatthetransportdensity *’cannotbechangedinsoftware.3*’Don'tknowatthispointwhythisseemstooccur,/*’possiblysomethingtodowiththetransport?.*’Anyway,don'twanttolockouttheuserfrom0*’selectingatransportdensityforawritefrom.*’loadpoint,sochangethelogicinSELECT2to*’ignoretheCNGDENSflag.*4*’UseBRanchshortwhereverpossibleandaddapatch*’areaattheend.*8*ˆ4/7/84„ReplaceSELECT2callswithSELECTcalls.‚Modify *’SELECT.*5*ˆ5/22/84ƒRewritetheDOWRITEroutineusingWHILE-DO.2*’Addaperiodicactivationcalltotimeoutinthe5*’driverifDOREADtakestoolong.‚Wedothisbecause6*’IOSsendsusatimeoutfortheIOSRTOvalueandthis9*’mustmakedofornotonlyread,butrewind,search,and:*’everythingbutwrite.Wewantashortreadtimeoutbuta1*’longrewindtimeoutsowemustdoitourselves.4*’Thisrequireschangestothe9995..IOE.EQfileand*’anewsysgentotest.*<*ˆ6/15/84ƒIfuserasksforatimeoutwitha0interval,just*’treatasnotimeout.:*’Afteracommandhascompleted,inhibitinterruptsatthe8*’boardandenableinterruptsatthesystemlevel(lower0*’maskby1)sothatwedon'ttieupthesystem.*<*ˆ9/18/84ƒFoundaproblemwhiletestingonVM03.‚Continually3*’gettingtimedoutduringreads.‚Timingdependent.3*’TheproblemwasIwasreadingSTAT1asecondtime4*’intheinterruptserviceroutine,andtherewasan<*’interruptpendingthatgotclearedbutwasneverserviced.*5*’Itispossibleforthefollowingsequencetooccur:8*’HALFFULLinterruptoccurs,ReadSTAT2,‚FNBSYinterrupt4*’occurs,readSTAT1.‚Inthiscasewewillnotgeta*’FNBSYinterrupt.8*’ThereforewhenitistimetocheckforFNBSY,readthe6*’bit4inSTAT1todecideifitisaFNBSYinsteadof*’thebit1inSTAT2.*’ChangesmadeinMTINT.*;*ˆ12/04/84‚Ontapedrivesrunningat100ipsontheVME/10,5*’theREAD2Kroutinewasnotgettingbytesoutofthe0*’FIFOfastenough.‚Speededuptheprimaryloop.1*’Thisreducedthetimebetween4bytereadsfrom4*’25.6microsecondstoabout11microseconds,which*’didthetrick.*7*’OntapedrivesthatdonotconformtothePERTECspec6*’forwhichtheMVME435boardwasdesigned,readingin,*’directmodecorruptedbytesontheVME/10.4*’Asaworkaround,thedrivernowreadsinbuffered4*’modewhentheuserspecifiesabuffersizeof40962*’bytesorless.‚I'mnotsurewhy,butonthetape4*’drivesIusedfortesting,therewillbemorethan6*’4096bytesreadfromtheMVME435whenthetapeblock7*’sizeislargerthan4096,evenwhenwearereadingin-*’bufferedmode.‚Thisisagoodfeature,asa2*’bufferoverflowmessagewillalerttheuserthat6*’theblocksizeonthetapeisindeedlargerthanhis;*’4096bytebuffer.Butmostlyweexpecttheuserknowsthe%*’sizeofthetapeblocksbeingread.*=*ˆ12/7/84ƒWhenauserasksfor0readtriesor0writetries,&*’thedrivershouldchangethe0to1.9*’ThatwasnotbeingdoneintherightplaceinCONFGCOM.*I**************************************************************************(*ˆMODULESCALLEDINTHEMAGTAPEDRIVER:*H*--------------------ƒINITIA- LIZATIONƒ-----------------------------------*<*INITIAL‚EQU‡*‡InitializesthedevicedependentpartofCCB$*œInitializesMVME435andtapedrive*K*--------------------------------------------------------------------------*H*--------------------ƒCOMMANDSERVICE‚----------------------------------**6*COMMANDSEQU‡*‡DispatchescommandsreceivedfromCMR**STATCMD‚EQU‡*‡Statuscommand.*STATCONFEQU‡*‡Updatesfirst4bytesofIOCB!*DFCONFG‚EQU‡*‡Defaultconfigure*CONFG„EQU‡*‡Configurecommand5*CONFGCOMEQU‡*‡Executescommonconfigurationchores**?*CONERROREQU‡*‡Errorexitforconfigureanddefaultconfigure*1*RDWRTCMDEQU‡*‡Entryforreadandwritecommand@*COMMCMD‚EQU‡*‡EntryforI/Ocommandsotherthanread,write,or*œconfigure&mount2*CONFG2ƒEQU‡*‡Entrypointforconfigureandmount *HALTCMD‚EQU‡*‡HaltI/Ocommand2*LOGPHYƒEQU‡*‡Convertlogicaltophysicaladdress***HALTEXITEQU‡*‡ExitforhaltI/Ocommand$*CMDEXIT‚EQU‡*‡Commandscommonexit;*CMDEXIT1“Entrypointforcommandscompletedwithouterror>*CMDEXIT2EQU‡*‡Entrypointforcommandscompletedwitherror9*CMDEXIT3EQU‡*‡Entrypointforcommandstobecompleted*œunderinterruptcontrol*%*QEVENTT”QueuesI/Ocompletionevent* *EXECREQ‚EQU‡*‡Doestrap0call *KILL_IT‚EQU‡*‡Killsthesystem*&*CMDSWIT‚EQU‡*‡TableusedinCOMMANDS'*CONFGLENEQU‡*‡TableusedinCONFGCOM*K*--------------------------------------------------------------------------*F*-------------------„INTERRUPTSERVICEƒ-------------------------------*%*INTERUPTEQU‡*‡Interpretsinterrupt+*MTINT„EQU‡*‡Dispatchesmagtapeinterrupt***PROCQUE‚EQU‡*‡Processesnextqueueentry'*SELECTƒEQU‡*‡Selectspropertransport-*œRe-selectstransportwithrequesteddensity*œforwritefromloadpoint**DOWRITE‚EQU‡*‡Writetotape<*WRITE2K”Transfer2KbytesfromFIFOtomemory(directmode)3*WRITDATAEQU‡*‡TransferbytesfromFIFOtomemory*>*DOCONFG‚EQU‡*‡Dotheconfigureandmount(interruptcontrol)&*FINDDENSEQU‡*‡Findthetapedensity1*SET_TIME“Dotrap0callforperiodicactivation*œduringFINDDENScommand.2*WAKEUP•Routinethatisactivatedduringperiodic'*œactivationwakeupcallfromFINDDENS.;*WAKEUP2”RoutineforwakeupcallsfromDOREAD,SPACE,ERASE*œSEARCH,andDOREWIND*+*DORDFWD‚EQU‡*‡Dothereadforwardcommand.*READ2K•Transfer2KbytesfromFIFOtomemory*ž(directmode)3*READDATAEQU‡*‡Transferbytesfrom‚FIFOtomemory+*žbufferedmode/endofblockindirectmode*;*STOPTAPE“Afterresetformattercommand,waitforthetape2*žtostop,cleartheformatternotbusyinterrupt.**&*DOREWINDEQU‡*‡Dotherewindcommand*;*DOSFMFWDEQU‡*‡Dothesearchforwardforfilemarkcommand;*DOSFMREVEQU‡*‡Dothesearchreverseforfilemarkcommand+*SEARCH•Commonroutineforsearchfilemark*,*DOSPFWDEQU‡*ˆDothespaceforwardcommand,*DOSPREVEQU‡*ˆDothespacereversecommand2*SPACE–Commonroutineforspaceforward&reverse*-*DOWRTFM‚EQU‡*‡Dothewritefilemarkcommand$*DOERASE‚EQU‡*‡Dotheerasecommand:*FM_ERAS_COMMCommonroutineforeraseandwritefilemark*;*MTADONE‚EQU‡*‡Completecommandprocessingunderinterrupt *œcontrol%*QEVENTI”QueuesI/Ocompletionevent*3*CKRDY–Seeifthetransportisready.Ifnotready,*œimmediately,delayforawhileuntilitis*œorwehaverunoutoftime.*#*IDLELOOPEQU‡*‡Waitforacommand*%*OPTABLE‚EQU‡*‡TableusedinPROCQUE*TRTABLE”TableusedinSELECT*I*------------------------------------------------------------------------F**********************************************************************‰PAGEI***************************************************************************ˆMAGTAPE.MACROS.SA*J*************************************************************************** *ˆMacrosforthemagtapedriver*J****************************************************. **************************A*<<<<<<<<<<<<<<<<<< COMMENTED OUT 12/2/83 >>>>>>>>>>>>>>>>>>>>>>>*<*ˆItwasdiscoveredthatgettingreadytakessometransports:*ˆlongerthanothers,soweneededatimeouttotestready(*ˆafteradelayofseveralmilliseconds. *ˆAsubroutinedoesthejobnow.****ƒCKRDY„MACRO**?*ˆPutthenotreadyerrorcodeintoD1,andcheckthereadybit=*ˆoftheSTAT1register.‚Ifthetransportisnotready,goto *ˆMTADONE.*****†MOVE.B„#ISTANR,D1***†BTST†#READYB,STAT1(A0)***†BEQ.S‡MTADONE***†ENDM***CKEOT„MACRO**<*ˆPuttheendofvolume(endoftape)errorcodeintoD1and2*ˆchecktheendoftapebitoftheSTAT1register.**ˆIfweareatendoftape,gotoMTADONE.**‰MOVE.B„#ISTAEOV,D1‰BTST†#EOTB,STAT1(A0)‰BNE.L…MTADONE‰ENDM***INHIB„MACRO**"*ˆInhibitinterruptsatourlevel.**‰MOVE.W„CCBISR(A5),SR‰ENDM7*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ˆbwn‡4/4/84*INHIBMTA MACRO*"*ˆInhibitinterruptsattheboard.**‰MOVE.B„#DISABLCD,DSCMD(A0)‰ENDM*/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ENABL„MACRO**2*ˆEnableinterruptsbyloweringmaskbyonelevel.**‰MOVE.W„CCBSR(A5),SR‰ENDM*D*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ˆbwn‡4/4/84*'*ˆEnableinterruptsattheboardlevel.**ENABLMTA MACRO**‰MOVE.B„#ENABLECD,DSCMD(A0)‰ENDM**F*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%**8*ˆCheckfilemarkandifafilemarkwasdetected,putthe)*ˆISTAEOFmessageinD1andgotoMTADONE** CKFM…MACRO‰MOVE.B„#ISTAEOF,D1‰TST.B…SAVEFM(A1)‰BNE.L‡MTADONE‰ENDM***8*ˆCheckforbeginningoftapeandifso,puttheISTABOV!*ˆmessageinD1andgotoMTADONE**CKBOT„MACRO‰MOVE.B„#ISTABOV,D1‰BTST†#LDPNTB,STAT1(A0)‰BNE.L‡MTADONE‰ENDM**6*ˆCKTRDENmacroupdatesthecurrenttransportdensity.8*ˆItrequiresthatA0=addressofmemory-mappedIOarea-*ˆandA1=addressofdrive'svariableblock.** CKTRDEN‚MACRO‰TST.B…STAT1(A0)‰IFˆ†THEN.S“MOVE.B„#XDSD800,TRANDENS(A1)‰ELSE.S“MOVE.B„#XDSD1600,TRANDENS(A1)‰ENDI‰ENDM * *ˆTRACEmacrousedfordebuggingH*ˆIftheTRACEis'ON',thenwheneverthemacroTRACEXXisencountered,7*ˆthecharacters'XX'willbeputintothetracetable.*ˆCall:ƒTRACER1,RTR8*Thiswillputthecharacters'R1'intothetracetable6*thatstartsatRTR_TABLEandisindexedbyRTR_INDEX*andhaslengthRTR_LEN.* TRACE„MACRO‰IFEQ†TRACE-'ON'MOVE.W…D0,-(SP)MOVE.W…#\2_TABLE,D0ADDƒ\2_INDEX(A5),D0MOVE‚#'\1',(A5,D0)ADD.W#2,\2_INDEX(A5)"IF„\2_INDEX(A5)‚‚#\2_LENƒTHEN“CLR„\2_INDEX(A5)ENDIMOVE.W…(SP)+,D0‰ENDC‰ENDM *@*ˆTheCLR_TRmacroisusedtoclearthetracetableofinterest.*ˆCall:CLR_TRƒRTR3*ŽThisclearstheRTR„tablefromoffset0tooffset*ŽRTR_LEN-1.*CLR_TRƒMACRO‰IFEQ†TRACE-'ON'MOVEM.L‰D4/A3,-(SP)LEAƒ\1_TABLE(A5),A3FORƒD4=#1‚TO‚#\1_LENƒDO“CLR.B…(A3)+ENDFCLRƒ\1_INDEX(A5)MOVEM.L‰(SP)+,D4/A3‰ENDC‰ENDM G************************************************************************Í*'*ˆFromtheSASIdriverbyDavidPheanis*C******************************************************************* 2LONGWORDMACRO›Thismacroskipszeroormorebytes'*¦inmemory(ifnecessary)toalignthe)*¦assembler'slocationcountertoalong-&*¦wordboundary.‚Wedefinealong-word)*¦boundarytobealocationwhoseaddress*¦isevenlydivisibleby4. ,‰DS.W…0–First,alignthelocationcounterto"*¦awordboundary.‚Ifthelocation(*¦counterisalreadyonawordboundary,*¦wedon'tchangeit. 0‰IFNE…*/4*4-*Ifthelocationcounterisn'tona-‰DS.W…1”long-wordboundary,advanceitbyone-‰ENDCšwordtoputitonalong-wordboundary. ‰ENDM-‰PAGEš##############################. #########1MOVEIAƒMACRO›Thismacroisusefulwhenwewantto%*¦putanimmediatevalueintoan"*¦register.‚Iftheimmediatevalue"*¦happenstobesmallenoughtobe#*¦representedcorrectlyina16-bit&*¦two's-complementnumbersystem,this#*¦macrogeneratesatwo-wordMOVE.W)*¦instructionknowingthatsignextension)*¦willoccuratexecutiontimetosetthe'*¦entireregisterproperly.‚Other-(*¦wise,themacrogeneratesathree-word#*¦MOVE.Linstruction.‚Byusingthis'*¦macrowecanbeassuredofgenerating'*¦theshortestcorrectinstruction,and)*¦themacrowillstillfunctioncorrectly#*¦iftheimmediatevaluehappensto&*¦changeasaresultoffutureprogram$*¦modifications.‚TheMOVEIAmacrois*¦invokedasfollows. "*¦[]MOVEIAƒ,An (*¦Noticethatthecustomary"#"mustnot'*¦beincludedaheadofthe%*¦thatistobeusedastheimmediate(*¦value.‚Also,themustnot!*¦containanyforwardreferences. 2‰IFLE…\1-$7FFFIftheimmediatevalueislessthan/‰IFGE…\1+$8000orequalto$7FFFanditisalso2‰MOVE.Wƒ#\1,\2greaterthanorequalto-$8000,it,‰MEXIT™fitswithina16-bitwordasasigned(‰ENDCšvalue.‚Inthiscase,weuseatwo-‰ENDCšwordMOVE.Winstruction. 2‰MOVE.Lƒ#\1,\2‘Otherwise,wemustuseathree-word*¦MOVE.Linstruction. ‰ENDM-‰PAGEš#######################################2MOVEQBƒMACRO›Thismacroisusefulwhen(1)wewant(*¦toemployaMOVEQinstructiontoputa'*¦valueintotherightmostbyteofaDn%*¦registerand(2)wedon'tcarewhat(*¦valuegoesintotheotherbytesofthe'*¦Dnregister.‚AMOVEQinstructionsign&*¦extendsabyte-sizedimmediatevalue)*¦andfillsanentireDnregister,sothe(*¦assemblergivesusawarningifweuse'*¦aMOVEQinstructionwithanimmediate'*¦valuegreaterthan$7F.‚Byusingthis"*¦macrowecanavoidtheassembler)*¦warningwhenwespecificallydon'tcare'*¦whathappenswiththesignextension,%*¦sowecanuseanunsignedimmediate#*¦valueaslargeas$FForasigned(*¦immediatevalueintherangefrom-$80#*¦through+$7F.‚TheMOVEQBmacrois*¦invokedasfollows. "*¦[]MOVEQBƒ,Dn (*¦Noticethatthecustomary"#"mustnot'*¦beincludedaheadofthe%*¦thatistobeusedastheimmediate(*¦value.‚Also,themustnot!*¦containanyforwardreferences. "*¨Thebasicideaforthismacrois'*¦derivedfromasimilarmacrothatwas*¦writtenbySteveFranck. .‰IFGT…\1-$7F‘Iftheimmediatevalueisgreater1‰IFLE…\1-$FFthan$7Fanditisalsolessthanor?‰MOVEQ„#\1+$FFFFFF00,\2…equalto$FF,providesignextensionat&‰MEXIT™thesourceleveltopreventthe-‰ENDCšassemblerfromgivingawarningmessage‰ENDCšthatwedon'twant. 3‰MOVEQ„#\1,\2‘Otherwise,usetheimmediatevalueas'*¦itis.‚Iftheimmediatevalueisout-$*¦sidetherangethatcanfitintoa$*¦singlebyte,we'llgetanerrorto*¦alertustotheproblem. ‰ENDM-‰PAGEš#######################################2MOVEQWƒMACRO›Thismacroisusefulwhen(1)wewant$*¦toputanimmediatevalueintothe)*¦rightmostwordofaDnregisterand(2)(*¦wedon'tcarewhatvaluegoesintothe'*¦otherwordoftheDnregister.‚Ifthe)*¦immediatevaluehappenstofitwithina#*¦singlebyteasatwo's-complement&*¦signedvalue,thismacrogeneratesa(*¦one-wordMOVEQinstruction.‚Otherwise,'*¦themacrogeneratesatwo-wordMOVE.W%*¦instruction.‚Byusingthismacrowe"*¦canbeassuredofgeneratingthe'*¦shortestcorrectinstruction,andthe(*¦macrowillstillfunctioncorrectlyif'*¦theimmediatevaluehappenstochange)*¦asaresultoffutureprogrammodifica-'*¦tions.‚TheMOVEQWmacroisinvokedas *¦follows. "*¦[]MOVEQWƒ,Dn (*¦Noticethatthecustomary"#"mustnot'*¦beincludedaheadofthe%*¦thatistobeusedastheimmediate(*¦value.‚Also,themustnot!*¦containanyforwardreferences./ 0‰IFLE…\1-$7F‘Iftheimmediatevalueislessthan3‰IFGE…\1+$80orequalto$7Fanditisalsogreater5‰MOVEQ„#\1,\2thanorequalto-$80,itfitswithina-‰MEXIT™singlebyteasasignedvalue.‚Inthis+‰ENDCšcaseweuseaone-wordMOVEQinstruc-‰ENDCštion. 0‰MOVE.Wƒ#\1,\2‘Otherwise,wemustuseatwo-word*¦MOVE.Winstruction. ‰ENDM@****************************************************************‰PAGE*ˆINCLUDEƒ9995.&.IOE.EQ*ˆINCLUDEƒ9995.&.STR.EQ*ˆINCLUDEƒ9995.&.CCB.EQ*ˆINCLUDEƒ9995.&.TCB.EQ*ˆINCLUDEƒ9995.&.NIO.EQ*ˆINCLUDEƒ9995.&.LV5.EQ*‰INCLUDEƒ9995.&.IOE.EQ‰NOLIST‰INCLUDEƒ9995.&.STR.EQ‰NOLIST‰INCLUDEƒ9995.&.CCB.EQ‰NOLIST‰INCLUDEƒ9995.&.TCB.EQ‰NOLIST‰INCLUDEƒ9995.&.NIO.EQ‰NOLIST‰INCLUDEƒ9995.&.LV5.EQ‰PAGE‰LISTH**************************************************************************ˆMAGTAPE.CONFIG.SA*O*********************************************************************************%*ˆPARAMETERSMASKFORMAGTAPEDRIVER*O******************************************************************************* &*¨Noticethatsomeofthedefinedbits>*ƒ15‚14‚13‚12ƒ11‚10ƒ9ƒ8„intheparametersmaskarenotusedbyM*‚+---+---+---+---++---+---+---+---+‚themagtapedriver,butallofthebits5*‚|‡|ƒ|ƒ||ƒ|ƒ|ƒ|ƒ|‚thataredefinedforany‚driveare=*‚+---+---+---+---++---+---+---+---+‚showninthediagrams.{*„^ƒ^ƒ^ƒ^„^ƒ^ƒ^ƒ^ª{*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ|ª{+*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ+---‚IOSRDTOissignificant*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|-*„|ƒ|ƒ|ƒ|„|ƒ|ƒ+-------‚IOSSPTOissignificant *„|ƒ|ƒ|ƒ|„|ƒ|0*„|ƒ|ƒ|ƒ|„|ƒ+------------IOSRWTOissignificant*„|ƒ|ƒ|ƒ|„|2*„|ƒ|ƒ|ƒ|„+----------------IOSSRTOissignificant *„|ƒ|ƒ|ƒ|0*„+--------------------------------‚Notdefined. *„7ƒ6ƒ5ƒ4„3ƒ2ƒ1ƒ0ª{&*‚+---+---+---+---++---+---+---+---+¨{*‚|ƒ|ƒ|ƒ|ƒ||ƒ|ƒ|ƒ|ƒ|¨{&*‚+---+---+---+---++---+---+---+---+¨{*„^ƒ^ƒ^ƒ^„^ƒ^ƒ^ƒ^ª{*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ|ª{;*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|ƒ----1=IOSRECissignificant(notused)‚{*„|ƒ|ƒ|ƒ|„|ƒ|ƒ|®{=*„|ƒ|ƒ|ƒ|„|ƒ|ƒ--------1=IOSRSZissignificant(notused)‚{*„|ƒ|ƒ|ƒ|„|ƒ|²{4*„|ƒ|ƒ|ƒ|„|ƒ------------1=IOSWTOissignificant{ *„|ƒ|ƒ|ƒ|„|¶{6*„|ƒ|ƒ|ƒ|„----------------1=IOSRTOissignificant{*„|ƒ|ƒ|ƒ|»{:*„|ƒ|ƒ|ƒ---------------------1=IOSDENissignificant.Œ{ *„|ƒ|ƒ|¿{<*„|ƒ|ƒ-------------------------1=IOSRDTissignificant.Œ{*„|ƒ|Ã{>*„|ƒ-----------------------------1=IOSWRTissignificant.Œ{*„|Ç{>*„---------------------------------1=IOSERTissignificant.-‰PAGEš#######################################L1‡SET†1<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*>SAVEADDRDS.L†1‰VariabletosavethereturnaddressforCKRDY.)*œWewanttodoatrap0requestperiodic+*œactivationcallfromthissubroutine,then-*œaBSR.SINTRTN.‚Thestackwillbemessedup**œunlessweripthereturnaddressoffthe+*œstackandsaveitheresowecangetback*œtothecallingroutine.*=*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*7*ˆ0 Herewereserveroomforatracetablefordebugging.**‡DS„0**†TRACETABLEFORREADSRTR_LENEQUƒ$40‡IFEQ…TRACE-'ON'RTR_INDEX‚DS„1RTR_TABLE‚DS.B‚RTR_LENˆENDC**†TRACETABLEFORWRITESWTR_LENEQUƒ$20‡IFEQ…TRACE-'ON'WTR_INDEX‚DS„1WTR_TABLE‚DS.B‚WTR_LENˆENDC*‡DS„0 *†TRACETABLEFOROTHERCOMMANDSTR_LENEQUƒ$20‡IFEQ…TRACE-'ON' TR_INDEX‚DS„1TR_TABLE‚DS.B‚TR_LENˆENDC***N****************************************************************************** *(*ˆDrive-associatedMT-definedCCBfields*N*******************************************************************************4DRVBLKƒDS.W†0‰Beginningofdrive-associatedareaand0*œlengthinbytesoftheCCBareathatpreceeds.* ‰OFFSET„0;ACTIVEƒDS.B†1‰Flagthatallowsthedrivertodosomeunique4*œprocessingforthefirstconfigurecommandthatis*œreceivedfromthediskdrive.**8MOUNTED‚DS.B†1‰Setwhenaconfigureandmountcommandis&*œreceivedandthedriveisready,and-*œweareabletoreadthetapefromloadpoint,*œtodeterminetapedensity,orweknowthat%*œwecannotchangetransportdensity./*œClearedwhenaconfigureanddismountcommand*œissuccessfullyexecuted.-*œThedriverallowsonlystatusandconfigure!*œcommandsifnotapeismounted.*7MOUNT1ƒDS.B†1‰Setwhenaconfigureandmountcommandis,*œreceivedandallparametersandattributes*œarevalid.2*œClearedwhenaconfigureanddismountcommandis*œsuccessfullyexecuted.2*œThisflagischeckedinSTATCONF,andtheIOSDST"*œstatusfieldissetaccordingly.3*œThisextraflagallowsIOStopassalongcommands1*œtothedriver,evenifnotapewasmountedwhen**œthesystembooted,aslongasthesysgen*œparameterscheckedoutok.*ALDPNTFLGDS.B†1‰Flagusedtoremindustochangethetapedensity*œafterwritefromloadpoint.*.‰DS.W†0‰GetconfigureblockontoevenboundaryCONFGBLKEQU‡*-IOSATW‰DS.B†IOSMLN-IOSATW.*œThisareaholdsthecurrentconfigurationof-*œthemagtapedrive,andisfilledinbythe&*œconfigurecommandandcopiedforthe*œstatuscommand.*œThefieldsinthisareaare:*œCONFGBLK+IOSATW*œCONFGBLK+IOSREC*¡.*¡.*¡.*œCONFGBLK+IOSDEN*œCONFGBLK+IOSRDT*œCONFGBLK+IOSWRT*œCONFGBLK+IOSERT*œCONFGBLK+IOSMTSV*4IOFUNCT‚DS.B†1‰IndexintoOPTABLE†tofindaddressof/*œcodetoexecuteforacommandunderinterrupt *œcontrol.*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>@SAVEEOT‚DS.B†1‰Variabletosavethefactthatwehitendoftape*K*<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>@SAVEMSG‚DS.B†1‰Variabletoholderrormessagebetweeninterrupts*œUsedinFINDDENSandDORDFWD*REQDENS‚DS.B†1‰Flagtoindicatewhethertheuserisrequesting-*œadensitybesidesdefaultdensityforwrite*œfromloadpoint.*œ$80:requestingadensity*œ$00:notrequestingadensity**œ0=1600bpi,1=800bpi*>MOTIONƒDS.B†1‰Thedirectioninwhichthetapewillmoveduring*œexecutionofthecommand.*œ00=FORWARD*œ01=REVERSE*œ02=DON'TCARE*>CONBLOCKDS.L†1‰Physicaladdressoftheusertask'sconfigure/)*œstatusblock.‚SavedinCONFGCOMwhenwe)*œhaveaconfigureandmountcommandthat,*œwillbecompletedunderinterruptcontrol.*.IOBUFLENDS.L†1‰NumberofbytesinI/Obuffer.*8SAVELEN‚DS.L†1‰Variabletoholdthelengthofthebuffer0*œbetweeninterruptsonareadcommandindirect*œmode./*œAnparityerrormaybedetectedafterwehave-*œtransferredsomedata,andwemustpreserve*œIOBUFLENforretries.*N*******************************************************************************:*ˆThefollowingfieldsmustnotchangepositionsincethey5*ˆareaccessedusingaMOVEMinstructioninthecode.*O********************************************************************************2IOBUFLOCDS.L†1‰Physicaladdressoffirstlocation*œofI/Obuffer.*ˆtheCCBforthemagtapedriver.‚CMRautomaticallyallocates?*ˆonepageofmemory($100b1 ytes)fortheCCB,andourvariable8*ˆEXTCCBSZwillresideintheCMRparametertableattheD*ˆbeginningofthedrivertotellCMRhowmanyextrapagesofmemory *ˆareneeded.****CCBSIZEBEQU‡*+DRVBLKŒSizeinbytesofCCBPAGESIZEEQU‡$100L0012„EQU‡CCBSIZEB+PAGESIZE-1CCBSIZE‚EQU‡L0012/PAGESIZEEXTCCBSZEQU‡CCBSIZE-1**L0020„EQU‡CCBSIZE*PAGESIZECCBZSIZEEQU‡L0020-CCBZERO**L****************************************************************************H************************************************************************‰PAGEH**************************************************************************ˆMAGTAPE.EVENT.SA*N*********************************************************************************ˆEVENTSTRUCTURE**J************************************************************************** '‰OFFSETƒ0–ThisOFFSETblockdefinesthe'*¦structureofanI/Oevent.‚Weuseone)*¦variationoftheeventstructureforan"*¦I/Ocompletionevent,andweuse *¦anothervariationoftheevent%*¦structureforanunsoliciteddevice*¦event. 1L0010„EQU†*–Thislabelmarksthefirstbyteofan(*¦eventblock.‚We'llusethislabelasa(*¦baseaddressforcomputingthelengths*¦ofcertainkindsofevents. 1EVNTLEN‚DS.B…1–Thisfieldspecifiesthelengthof'*¦theevent.‚Thelengthisspecifiedin%*¦termsofthenumberofbytesinthe*¦event. 3EVNTCODEDS.B…1–Thisfieldcontainstheeventcode,4EVNTIOƒEQU†$01’whichspecifiestheclassificationofƒ0‚|„STAT2…|‚read*˜+--------------+*Ÿ.*Ÿ.*Ÿ.*˜+--------------+*•8‚|ƒLASTWRD„|‚write*˜+--------------+*Ÿ.*Ÿ.*Ÿ.*˜+--------------+*”16‚|ƒDIRSL†|‚write*˜+--------------+*Ÿ.*Ÿ.*Ÿ.*˜+--------------+*”23‚|Ž|*˜+--------------+*‰PAGE***ˆMVME435MEMORY-MAPPEDIOSPACECONTINUED* 1‰OFFSET„-41‘CCBCHBoftheCCBpointstotheSTAT2'*¦registeroftheMVME435memory-mapped%*¦IOspace,andsowemustcompensate *¦bystartingwitha-41offset.**¦ThereasonwemusthavetheCCBCHBpoint#*¦to‚theSTAT2registeristhatthe&*¦registerwepointtomustnotgivea!*¦buserrorifwetrytoreadit,'*¦andSTAT2satisfiesthisrequirement.‰DS.B†1DATAIO0‚DS.B†8GRCMD„DS.B†8*0*ˆFormattercommands(writtentoGRCMDregister)*RDFWDCMDEQU…$00ReadForwardRDREVCMDEQU…$01ReadReverseWRITECMDEQU…$02WriteForwardWRTFMCMDEQU…$06Writefilemark,SFMFWDCDEQU…$14Searchforwardforfilemark,SFMREVCDEQU…$15Searchreverseforfilemark)SPFWDCMDEQU…$10Spaceforwardonerecord)SPREVCMDEQU…$11Spacereverseonerecord'ERASECMDEQU…$16Erase4inchesoftape*DSCMD„DS.B†8*/*ˆDiscretecommands(writtentoDSCMDregister)REWINDCDEQU…$01Rewindcommand(FORDISCDEQU…$04FormatterResetCommand"MTARSTCDEQU…$08MTAResetCommandOFLINCMDEQU…$02Offline:*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ˆbwn‡4/4/84"ENABLECDEQU…$10Enableinterrupts#DISABLCDEQU…$00Disableinterrupts;*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*TRSEL„DS.B†85TRSELDBEQU‡3Ifbit3=1,thenweareselecting800(*¢bpidensity.‚Ifbit3=0,thenweare*¢selecting1600bpidensity*STAT1„DS.B†8*READYBƒEQU‡0 ONLINEB‚EQU‡1LDPNTBƒEQU‡2 EOTB…EQU‡3FNBSYBƒEQU‡4 REWNDGB‚EQU‡5:WRTPRTB‚EQU‡6‰0=NOTWRITEPROTECTED,1=WRITEPROTECTED=NRZIB„EQU‡7‰0=PEFORMAT(1600bpi),1=NRZIFORMAT(800bpi)*STAT2„DS.B†8=BOTEOTDBEQU‡0‰Thisbitissetifoneofthefollowingoccur:*œ(1)loadpointdetected*œ(2)endoftapedetected.*œ(3)CCG/IDburstdetected(on1600bpitape)=FMFNBSYBEQU‡1‰Thisbitissetifoneofthefollowingoccur:*œ(1)filemarkdetected(*œ(2)formatteroperationcompleteafter* groupcommandSERVECT‚DC.L…INTERUPT-SERVECT‡This‚entry‚in‚the‚service‚vector(*¦tablecontainstherelativeaddress‚of!*¦the‚driver's‚interrupthandler.(*¦Theinterrupthandlerreceives‚control&*¦from‚CMR‚when‚CMRwishestopollthe*¦drivertoseeiftheƒdriver(*¦wants‚tohandlethecurrentinterrupt. 7‰DC.L…COMMANDS-SERVECT‡This‚entry‚in‚the‚service‚vector(*¦table‚containstherelativeaddressof!*¦the‚driver's‚command‚processor.&*¦CMR‚calls‚the‚commandprocessorwhen&*¦CMRhasacommandto‚initiate‚an‚I/O*¦transactiononachannel. 6‰DC.L…INITIAL-SERVECTˆThis‚entry‚in‚the‚service‚vector(*¦tablecontainstherelativeaddress‚of"*¦theƒdriver'sinitializationsub-'*¦routine.‚CMRcallsthe‚initialization'*¦subroutine‚at‚channelallocationtime)*¦togivethedriverachancetoallocate(*¦memory‚forvariablesand/ortodoany-'*¦thingthatisnecessary‚to‚initialize(*¦thechannelandthechanneldevice(s). 7‰DC.L…RESERVED-SERVECT‡This‚entry‚in‚the‚service‚vector:RESERVEDEQU†SERVECTŽtableis‚usedforSYSFAIL,butnotin*¦thisdriver.*‰PAGEK******************CMRƒPARAMETERTABLE************************************* 2‰DC.B…EXTCCBSZThisfieldtellsCMRhow‚many‚extra&*¦page(s),‚if‚any,‚toallocateforthe%*¦CCBforthisI/O‚driver.ƒCMR‚always(*¦allocates‚onemorethanthisnumberof'*¦page(s)becauseonepageof‚memory‚is&*¦required‚for‚the‚universally-defined'*¦CCBvariables.‚Theadditional‚page(s)&*¦that‚are‚specified‚bythisfieldare'*¦usedexclusively‚for‚device-dependent$*¦variables‚that‚are‚required‚by‚the*¦devicedriver. 0‰DC.B…0,0,0’Thesefieldsarereservedfor‚future.‰DC.L…0,0,0extensions.ƒWe‚provide‚zero‚values%*¦herebecause‚any‚extensions‚that‚we(*¦implement‚inthefuturewilli3 nterpret%*¦zeroasaninnocuousdefaultvalue.*‰PAGEN****************** REVISION TABLE ******************************************** 0‰DC.B…'09'‡MMŠThisportionof‚the‚revision‚table3‰DC.B…'18'‡DDˆcontains‚the‚dateonwhichthedriver3‰DC.B…'84'‡YYˆwasassembledforarelease.‚The‚date)*¦isgivenasMMDDYYwithtwodigitseach'*¦forthemonth,theday,andtheyear. .‰DC.B…''”ThisbytecontainsanASCIIblank‚to%*¦indicate‚that‚the‚driver's‚.LOfile*¦doesn'tcontainanypatches. .‰DC.B…'4'•ThisbytecontainsanASCIIdigit‚to&*¦indicate‚the‚major‚VERSAdosrevision(*¦numberunderwhichthisversionof‚the*¦driverwasfirstreleased. ‰PAGEN******************************************************************************N********************************************************************************ˆINITIALIZATIONROUTINE*D*ˆThesubroutineINITIALiscalledfromCMRwhenCMRisinvokedbyaC*ˆtask(normallyIOI)toallocateachannel.‚Itspurposeistogive>*ˆthedriverachancetosetthingsupforcommandserviceand*ˆinterruptservice.*$*ˆThebasicfunctionsperformedare:**8*‘Initializetheinterrupthandler'scoroutineswitchto*‘pointtotheMTAIDLEloop.*7*‘ClearthedevicedependentCCBvariablesfromCCBZERO*‘totheendofCCB.*<*’ThissetstheTAPEDENSfieldto00=1600bpi,eventhough8*’atthispointwedon'tevenknowifthereisatapeon6*’thetransport.‚However,aconfigurationcommandwill>*’callFINDDENSwhichwillputthepropervalueintoTAPEDENS.*8*’ThisalsosetstheIOSRDT,IOSWRT,andIOSERTfieldsin<*’eachdrive'svariableblockto0.Thefirstconfigurecall:*’willchangethesevaluestothedefaultsysgenedvalues.*3*’However,aconfigurationcallfromthesystemcan4*’insertotherdefaultvaluesbeforeareadorwrite*’commandisexecuted.**‘ResettheMVME435(MTA).*‘Resettheformatter.***%*ˆEntry:ƒA5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„* *™A„*ŽP‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister*$*ˆExit:„A6=physicaladdressofTCB**ˆExitsto:CMRviaRTS*M*****************************************************************************M***************************************************************************** INITIAL‚EQU‡***B*ˆInitializetheinterrupthandler'sco-routineswitchtopointto;*ˆtheMTIDLEroutine.‚IfweshouldgetacommandcompletionB*ˆinterruptbeforegivingacommand,theMTADOWNflagwillbeset,@*ˆandwhenthenextcommandisreceived,aneventwillbequeued?*ˆtoalerttherequestedofthecommandthatsomethingiswrong*ˆwiththecontroller.**‰LEA‡MTIDLE(PC),A0‰MOVE.L„A0,INTSWTCH(A5)**>*ˆClearallofthedevice-dependentCCBvariablesthatmustbe9*ˆbackgroundedwithzeroesatchannel-allocationtime.‚We:*ˆcleartwowordsatatimeuntilwe'veclearedallofthe=*ˆdevice-dependentvariablesthatliebetweenCCBZEROandthe*ˆendoftheCCB.2*ˆWesetupCCBZEROtobeonalongwordboundary.=*ˆCCBZSIZEwasfoundbytakinganumberdivisiblebyPAGESIZE!*ˆ($100)andsubtractingCCBZERO.**ˆThereforeCCBZSIZEisdivisiblebyfour.**‰LEA‡CCBZERO(A5),A0‰MOVEQW„(CCBZSIZE/4)-1,D0*INI010ƒCLR.L…(A0)+‰DBRA†D0,INI010*B*ˆGetthephysicaladdressofthechannel'smemory-mappedI/Oarea *ˆintoA0.**‰MOVE.L„CCBCHB(A5),A0**-*ˆResettheMVME435,andresettheformatter.:*ˆResettingtheMVME435willextinguishthefaillightand2*ˆwillalsoselectthetransport0offormatter0.**‰MOVE.Bƒ#MTARSTCD,DSCMD(A0)‰MOVE.Bƒ#FORDISCD,DSCMD(A0)*‰RTSN****************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆCO3 MMANDSERVICEROUTINE*L*‚Theentryconditionsforthissubroutinearegraphicallysummarizedbythe*‚followingdiagram.*%*‰+--------------+XIOUID‚+----------+*‚A2--->|‚CMR‰|------>|DCB†|*‰|‚Parameterƒ|ˆ|(Device‚|*‰|‚Block‡|ˆ|Control‚|*‰|Ž|ˆ|Block)ƒ|*‰|Ž|ˆ+----------+*‰|Ž|.*‰|Ž|XIOCPK‚+----------+‰+-------------------+1*‰|Ž|------>|IOCB…|------>|I/ODataBufferƒ|"*‰+--------------+ˆ|(I/O…|‰|…orŒ|"*¡|Control‚|‰|Status/Configure‚| *¡|Block)ƒ|‰|ParameterBlockƒ|$*¡+----------+‰+-------------------+**‰+--------------+ˆ+----------+*‚A5--->|CCBŠ|---+-->|TCB†|*‰|(Channel…|ƒ|„|(Task„|*‰|Control†|ƒ|„|Control‚|*‰|Block)†|ƒ|„|Block„|*‰+--------------+ƒ|„|for†|*œ|„|attached|'*‚A6-----------------------+„|task)„|*¡+----------+**C*ˆThissubroutineiscalledfromCMRwhenCMRreceivesacommandtoF*ˆinitiateanI/Otransactionwithadevicethatiscontrolledbythis *ˆdriver.*9*ˆThebasicfunctionsofthecommandserviceroutineare:*"*’SavethestackpointerinSAVESP&*’GetphysicaladdressofIOCBintoA4%*’GetphysicaladdressofDCBintoA3'*’GetthechanneldevicenumberintoD67*’Getaddressofdrive'svariableblockinCCBintoA1.#*’UsetheIOSFCTfield‚todetermine%*”thefunction‚valueforthecommand.(*’Usethefunctionvalueandthecommand*”switchingtable-*”togetanentryfortheMOTIONfieldofthe*”drive'svariableblock.9*”TheMOTIONfieldtellsusifthiscommandwillmovethe,*”tapeforwardorbackward.‚Whenwearedone0*”searchingthecommandswitchingtable,usethe3*”positionofthecommandinthetabletodetermine6*”avalueforIOFUNCT.‚Thiswillbeusedtoindexinto6*”theOPCODEtablewhenwearerunningunderinterrupt *”control.0*’Branchtotheroutine‚whoseaddresswasinthe*”commandswitchingtable.O**********************************************************************************ˆSubroutinescalled:‚LOGPHY*5*ˆEntry:„A2=physicaladdressofCMRparameterblock*’A5=physicaladdressofCCB/*’A6=physicaladdressofTCBofattachedtask*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„R…*‚*‚*‚R‚R*™A„*‚R‚P‚R‚R‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister*5*ˆExit:…A1=pointertodrive'svariableblockinCCB*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB9*’A6=physicaladdressoftheTCBthatcontrolsthetask*’D5=0*’D6=Channeldevicenumber**ˆExitsto:Oneof: *’STATCMD *’COMMCMD *’RDWRTCMD*’CONFG *’DFCONFG*M*****************************************************************************M******************************************************************************* CMDSWIT‚EQU‡**£IOFUNCT†OPTABLEentryin*°interrupthandler ‰DC.W†FORWARD‰DC.W†RDWRTCMD-*-4‰DC.W†IOREADŽ0‰DORDFWD ‰DC.W†FORWARD‰DC.W†RDWRTCMD-*-4‰DC.W†IOWRITŽ1‰DOWRITE ‰DC.W†FORWARD‰DC.W†COMMCMD-*-4‰DC.W†IOFMFWŽ2‰DOSFMFWD ‰DC.W†FORWARD‰DC.W†COMMCMD-*-4‰DC.W†IOSPFWŽ3‰DOSPFWD ‰DC.W†FORWARD‰DC.W†COMMCMD-*-4‰DC.W†IOERASŽ4‰DOERASE ‰DC.W†FORWARD‰DC.W†COMMCMD-*-4‰DC.W†IOWFMKŽ5‰DOWRTFM ‰DC.W†REVERSE‰DC.W†COMMCMD-*-4‰DC.W†IOFMRVŽ6‰DOSFMREV ‰DC.W†REVERSE‰DC.W†COMMCMD-*-4‰DC.W†IOSPRVŽ7‰DOSPREV**9*ˆTherewindcommandmotionis"don'tcare"atthispointF*ˆbecausewedon'twanttoreportanerrorifweareatloadpointwhen*ˆwereceivethiscommand**‰DC.W†DONTCARE‰DC.W†COMMCMD-*-4‰DC.W†IOREWDŽ8‰DOREWIND‰DC.W†DONTCARE‰DC.W†CONFG-*-4‰DC.W†IOCNFGŽ9‰DOCONFG**>*ˆThefollowingcommandsarenotdoneunderinterruptcontrol.**‰DC.W†DONTCARE#‰DC.W†DFCONFG-*-4“defaultconfigure‰DC.W†IOCHDC‰DC.W†DONTCARE!‰DC.W†HALTCMD-*-4“haltIOcommand‰DC.W†IOHALT‰DC.W†DONTCARE ‰DC.W†STATCMD-*-4“statuscommand‰DC.W†IOSTAT‰DC.W†-1œendoftableflagCOMMANDSEQU‡***?*ˆSavethestackpointer.‚Thestackpointerwillberestoredin *ˆCMDEXIT.**‰MOVE.L„SP,SAVESP(A54 )**>*ˆTestMTADOWN.‚MTADOWNissetifwegetaformatteroperation:*ˆcompletewhenwehavenotsentacommandtotheMVME435.D*ˆIfMTADOWNisset,queueaneventtotheattachedtasktoindicate-*ˆthatthechannelisoutofservicefornow.5*ˆClearMTADOWNsothatothercommandscanbesentto;*ˆtheMVME435.‚Theuserhasbeenwarned,andifhewantsto(*ˆcontinuewithanothercommand,hemay.&*ˆDrawback:justoneusergetswarned.**‰MOVEQB„ISTACDN,D1‰TST.B…MTADOWN(A5)‰SF.B†MTADOWN(A5)‰BNE.L…CMDEXIT2**?*ˆGetthephysicaladdressoftheIOCBforthecommandintoA4.C*ˆSubroutineLOGPHY1convertsthelogicalIOCBaddressinD6intoa*ˆphysicaladdressinD6.*ˆLOGPHY‚expects:*’A5=physicaladdressofCCB*’D5=lengthinbytesofIOCB"*’A0=physicaladdressoftheTCB+*—thatcontrolsthetaskthatownstheIOCBF*ˆLOGPHY‚abortsprocessingiftheIOCBthatwespecifyisnotentirely@*ˆwithinamemorysegmentthatbelongstothetaskthatownsthe*ˆIOCB.H*ˆInpractice,ahigherlevelroutinehasalreadyverifiedthattheIOCBE*ˆliesentirelywithinamemorysegmentthatbelongstothetaskthat*ˆownstheIOCB.**COM010ƒEQU‡*‰MOVE.L„XIOCPK(A2),D6‰MOVEQ.Lƒ#0,D5‰MOVE.W„XIOPLN(A2),D5‰MOVE.L„CCBTASKA(A5),A0 ‰BSR.L…LOGPHY ‰MOVE.L„D6,A4**B*ˆGetthephysicaladdressoftheDCBintoA3,andgetthechannel=*ˆdevicenumberintoD6.‚Thesevaluesindicatetheparticular0*ˆdevicethatshouldbeaccessedbythecommand.:*ˆIfthechanneldevicenumberisnotintherange0to7,>*ˆthenthereissomethingwrongwiththeDCB.‚Killthesystem.**‰MOVE.L„XIOUID(A2),A3‰MOVEQ.Lƒ#0,D6‰MOVE.B„DCBCDV(A3),D6‰BMI.L…KILL_IT‰IF.BƒD6‚‚#7ƒTHEN“BRA.L…KILL_IT‰ENDI**;*ˆSetupA1topointtothevariableblockforthemagtapeC*ˆdrivethatistobeaccessedbythecommand.‚Thedrive'svariable>*ˆblockisinthedrive-associatedportionoftheCCB,andtheF*ˆparticularvariableblockinthedrive-associatedareaoftheCCBis1*ˆindicatedbythedrive'schanneldevicenumber.*‰PAGEO*********************************************************************************ˆCCB*O*********************************************************************************ˆA5----->ƒ|-----------------|*”|‡.‰|*”|‡.‰|*”|‡.‰|*”|‘|*”|-----------------|*”|CCBTASKAˆ|*”|‘|----->‚|----------|*”|‘|‰|TCBofƒ|"*”|-----------------|‰|attached|*”|‘|‰|task…|*”|‘|‰|----------|*”|‘|*”|-----------------|*ˆCCBDDP--->|DeviceŠ|*”|Dependent‡| *”|Portion‰|*”|-----------------|<--*ˆDRVBLK--->|Device0ˆ|†\*”|‘|‡>‚DRVBLKSZ*”|‘|†/*”|-----------------|<--*”|Device1ˆ|*”|‘|*”|‘|*”|-----------------|*”|‡.‰|*”|‡.‰|*”|‡.‰|*”|-----------------|*”|Device7ˆ|*”|‘|*”|‘|*”|-----------------|***‰LEA‡DRVBLK(A5),A1‰MOVE.W„#DRVBLKSZ,D0‰MULU†D6,D0‰ADD.L…D0,A1**9*ˆSearchthecommandswitchingtableforthecommandthat;*ˆisspecifiedbytheIOSFCTandIOSOPTfieldsoftheIOCB.(*ˆIfwefindthecodeinthetable,then0*’D2=typeofmotion(FORWARD,REVERSE,DONTCARE)2*’D3=offset(fromA0)ofroutinewewilljumpto8*ˆIfwedonotfindthecodeinthetable,returnISTAIF*ˆinD1.**‰MOVE.W„IOSFCT(A4),D0‰LEA‡CMDSWIT(PC),A0‰MOVEQB„ISTAIF,D1)‰MOVE.B„#-1,D4ŽD4willholdIOFUNCTvalueCOM020ƒEQU‡* ‰ADDQ.B„#1,D49‰MOVE.W„(A0)+,D2ŒD2<---Motiondirectionorendoftable‰BMI.L…CMDEXIT2*‰MOVE.W„(A0)+,D3ŒD3<---‚Offsettoroutine‰CMP.W…(A0)+,D0ŒD0<---‚Command ‰BNE.S‡COM020**@*ˆIfcontrolreachesthispoint,thenwehavefoundthecommand.B*ˆComputethe‚IOFUNCTvalueforthecommandusingthevalueofA0.@*ˆPuttheFORWARD/REVERSE/DONTCAREvaluefromD2intotheMOTION&*ˆfieldofthedrive'svariableblock.>*ˆPutthedrivenumbervaluefromD6intotheDRIVENUMfieldof*ˆthedrive'svariableblock."*ˆClearD5(us4 edasaflaglater).4*ˆGototheroutinewhichdoeswhateverisnecessary*ˆbeforewereturntoCMR. *¶IOFUNCT*&*ˆCMDSWIT----->†+--------+--------+\*œ+--------+--------+ƒ\†0*œ+--------+--------+ƒ/*œ+--------+--------+/z˜RŠC’OšL¢Kª@²Hº_ÂEÊ@ÒKÚFâAêCòUúL3 @BF"?*@2G:MBAJ>RXZKb:j5*œ+--------+--------+\*œ+--------+--------+ƒ\†1*œ+--------+--------+ƒ/*œ+--------+--------+/*œ+--------+--------+\*œ+--------+--------+ƒ\†2*œ+--------+--------+ƒ/*œ+--------+--------+/*¥.*¥.*¥.*œ+--------+--------+\*œ+--------+--------+ƒ\†9*œ+--------+--------+ƒ/*œ+--------+--------+/*¥.*¥.*¥.*œ+--------+--------+\*œ+--------+--------+ƒ\…12*œ+--------+--------+ƒ/*œ+--------+--------+/‰MOVE.B„D4,IOFUNCT(A1)‰MOVE.B„D2,MOTION(A1)‰MOVE.B„D6,DRIVENUM(A1)‰MOVEQ…#0,D5‰JMP‡0(A0,D3.W)O*******************************************************************************‰PAGEN******************************************************************************N*******************************************************************************#*ˆSTATCMD--STATUSCOMMANDROUTINE*E*ˆThecommandserviceroutineinvokestheSTATCMDroutineinresponse?*ˆtoastatuscommand.‚Itspurposeistosetuptheusertask's;*ˆparameterblocktoreflectthedrive'scurrentstatusand*ˆconfiguration.*F*ˆThestatuspropertiesofinteresttotheuserofthemagtapedriver*ˆare:**’INIOSDST**’(1)deviceready3*–Thedeviceissaidtobereadyifaconfigureand9*–mountcommandhasbeenreceivedwithcorrectparameters*–andattributes0*–sincesysteminitialization,orsincethelast*–dismountcommand.5*–Thetapedrivebeing"ready"inthissensedoesnot.*–necessarilymeanthatitisreadytoreceive1*–readorwritecommands,asthetapedensitymay*–notyetbedetermined.**’(2)tapedensity,*–Ifthedeviceismounted,wecandetermine/*–whetherthetapehaspreviouslybeenrecorded-*–andifso,atwhatdensityitwasrecorded.**’(3)writeprotected8*–Ifthedeviceismounted,wecandeterminewhetherthe!*–writeenableringisonoroff.*-*’(4)driverabletochangetransportdensity3*–OntheCDCdrive,ifcertainjumpersareon,then3*–densityisselectableinsoftware.‚Wedetectthis'*–duringaconfigureandmountcommand.**’INIOSCTP,IOSDTP,IOSDRC**’(5)devicetype'*–Thedevicetypeismagtape(XDSTAPE)**’(6)channeltype3*–ThechanneltypeistheentryinCCBTYPEfieldof *–theCCB.**’(7)drivercode3*–ThedrivercodeisIOSMTAfortheMVME435driver.*‰PAGEL******************************************************************************ˆIOCBforstatuscommand*K*****************************************************************************”|----------------|*ˆA4---->„|IOSFCT‰|*”|----------------|*”|IOSOPT‰|*”|----------------|*”|IOSSTA|IOSLUN|*”|----------------|*ˆIOSSRV--->|ˆ|IOSPKL|*”|----------------|'*”|IOSDBP‰|„LogicalDataBlockPointer*”|--------|*”||---->|------------------|)*”|----------------|†|Configure/Status|*¬|ParameterBlock‚|*¬|forMagTape…|*¬|DriveŒ|*¬|------------------|**‰PAGEO********************************************************************************8*ˆCONFIGURE/STATUSPARAMETERBLOCKFORMAGTAPEDRIVER*O*********************************************************************************”|-----------------|2*”|IOSDST|IOSCTP|ƒDevicestatus|ChannelType*”|-----------------|/*”|IOSDTP|IOSDRC|ƒDevicetype|DriverCode*”|-----------------|*”|IOSATMŠ|ƒAttributesmask*”|-----------------|(*„Bitnumbers…|IOSPRMŠ|ƒParametersMask*„inIOSPRM‡|-----------------|"*„field‹|IOSATWŠ|ƒAttributesWord*…----5 ----‡|-----------------|#*ˆ0‹|IOSRECŠ|ƒVersadosRecordSize*”|-----------------|*ˆ1‹|IOSRSZŠ|ƒDeviceSize*”|---------|*”|‘|*”|-----------------|*ˆ2‹|IOSWTOŠ|*”|---------|*”|‘|*”|-----------------|*ˆ3‹|IOSRTOŠ|*”|---------|*”|‘|*”|-----------------|"*†4,5IOSDDC-->|IOSDEN|IOSRDT‚|*”|-----------------|*†6,7‹|IOSWRT|IOSERT‚|*”|-----------------| *ˆ8‹|IOSRDTOŠ|ƒTimeoutforread*”|---------|*”|‘|*”|-----------------|1*ˆ9‹|IOSSPTOŠ|ƒTimeoutforspaceforward/reverse"*”|---------|ƒforfilemark*”|‘|*”|-----------------|#*‡$A‹|IOSRWTO‰|ƒTimeoutforrewind*”|---------|*”|‘|*”|-----------------|3*‡$B‹|IOSSRTO‰|ƒTimeoutforsearchforward/reverse"*”|---------|ƒforfilemark*”|‘|*”|-----------------|%*”|IOSMTSV‰|‚Reservedforfutureuse*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*>*ˆIOSDEN--densityrequestedbyuserforwritefromloadpoint*‹XDSD800=800bpi*‹XDSD1600=1600bpi4*ˆIOSRDT--numberofreadtriesbeforeerrorreport0*ˆIOSWRT--numberofwritetriesbeforeerasure2*ˆIOSERT--numberoferasuresbeforeerrorreport*C*ˆIOSMLN=lengthinbytesofaconfigure/statusblockformagtape*‰PAGEO******************************************************************************** *ˆIOSDST„(bitssetbyMTdriver)*+*ˆ-----------------------------------------*ˆ|„|„|„|„|„|„|„|„|+*ˆ----------------------------------------- *Š^‰^„^‰^„^…^ *Š|‰|„|‰|„|…|**Š|‰|„|‰+----+-----+-----bits2,1,and0*Š|‰|„|›tapedensity*Š|‰|„|›1=XDSD800orblank*Š|‰|„|Ÿorcouldnot*Š|‰|„|Ÿdetermine*Š|‰|„|›0=XDSD1600*Š|‰|„|8*Š|‰|„+--------------------------1=densityselectable*Š|‰|¤insoftware*Š|‰| 0=densityselectable*Š|‰|¤bybuttonsofpanel*Š|‰|¤(XDSCGB=4)*Š|‰|6*Š|‰+-------------------------------1=Tapeiswrite *Š|®protected*Š|ª0=Tapeisnotwrite *Š|®protected*Š|*Š|*Š|E*Š+-----------------------------------------‚1=TapeDrivenotready *¹**seenote*¶0=TapeDriveready*?*ˆ**Thisbitissetiftheinitialconfigureandmountcommand9*‹fromIOSfailsbecauseofabadparameterorattribute,9*‹andalsowhenaconfigureanddismountcommandwithall.*‹validparametersandattributesis‚received.*2*ˆIOSCTPgiveninCCBTYPEfieldofCCBforchannel***ˆIOSDTPisXDSTAPE($05)formagnetictape*;*ˆIOSDRCisIODMTA($06)fortheMTAdriver(newdefinition)**O*******************************************************************************O*********************************************************************************ˆSubroutinescalled:STATCONF***6*ˆEntry:„A1=pointertodrive'svariableblockinCCB*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB.*’A6=physicaladdressofTCBofattchedtask*3*’D6=Channeldevicenumberforthemagtapedrive *œ(DCBCDV)*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D–**™A‡P‚*‚P‚P‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB.*’A6=physicaladdressofTCBofattchedtask**ˆExitsto:CMDEXIT*M*****************************************************************************M****************************************************************************** STATCMD‚EQU‡***4*ˆGettheaddressoftheIOSATWfieldofthedrive's*ˆvariableblockintoA2**‰LEA‡CONFGBLK+IOSATW(A1),A2**?*ˆBranchtotheSTATCONFsubroutine,whichsetsA0=pointerto;*ˆtheIOSDSTfieldoftheuser'sstatusblock,andfillsin8*ˆtheIOSDST,IOSCTP,IOSDTP,andIOSDRCfields,5 returning:*ˆwithA0=pointertoIOSATWofusertask'sstatusblock.:*ˆSTATCONFreturnsthe‚physicaladdressoftheusertask's=*ˆconfigure/statusblockinD6,anditusesasparametersthe*ˆvaluesinA1,A4,andA5.**‰BSR.S‡STATCONF**9*ˆFillintheIOSATMandIOSPRMfieldsoftheusertask's9*ˆstatusblockwiththemaskbitsthataresignificantto*ˆthemagtapedriver.**‰MOVE.L„#IOATM<<16+IOPRM,(A0)+**>*ˆThecodebelowassumesthatthestatusblockalwayscontains8*ˆanintegralnumberofwords.‚Ifthisassumptionisnot:*ˆtrue,wewanttogenerateanassemblyerrortoalertthe**ˆmaintenanceprogrammertothesituation.7*ˆIfthereareanintegralnumberofwords,wecanmove0*ˆvaluesfromtheconfigureblockinthedrive's4*ˆvariableareaoftheCCBtotheusertask'sstatus7*ˆparameterblockawordatatimeinsteadofabyteat *ˆatime.**ST030„EQU‡IOSMLN-IOSATWST040„EQU‡ST030/2ST050„EQU‡ST040*2‰IFNE†ST030-ST050 ‰FAIL†400‰ENDC*‰MOVE.W„#ST040-1,D0ST060„MOVE.W„(A2)+,(A0)+‰DBRA†D0,ST060*‰BRA.L…CMDEXITJ**************************************************************************‰PAGEN******************************************************************************N*******************************************************************************6*ˆSTATCONF--DOCHORESCOMMONTOSTATUSANDCONFIGURE*<*ˆTheSTATCONFroutinedoesthechorescommontothestatus,,*ˆconfigure,anddefaultconfigureroutines.A*ˆSTATCONFgetsthephysicaladdressoftheusertask'sconfigure?*ˆblock,andmovesthepropervaluesintothefollowingfields::*’IOSDSTdevicestatus(ready,writeprotect,tapedensity)/*’IOSCTPchanneltypefromCCBTYPEfieldofCCB*’IOSDTPdevicetype(magtape)*’IOSDRCdrivercode(IODMTA)*O******************************************************************************** *ˆIOSDST„(bitssetbyMTdriver)*+*ˆ-----------------------------------------*ˆ|„|„|„|„|„|„|„|„|+*ˆ----------------------------------------- *Š^‰^„^‰^„^…^ *Š|‰|„|‰|„|…|**Š|‰|„|‰+----+-----+-----bits2,1,and0*Š|‰|„|›tapedensity*Š|‰|„|›1=XDSD800orblank*Š|‰|„|Ÿorcouldnot*Š|‰|„|Ÿdetermine*Š|‰|„|›0=XDSD1600*Š|‰|„|8*Š|‰|„+--------------------------1=densityselectable*Š|‰|¤insoftware*Š|‰| 0=densityselectable*Š|‰|¤bybuttonsofpanel*Š|‰|¤(XDSCGB=4)*Š|‰|6*Š|‰+-------------------------------1=Tapeiswrite *Š|®protected*Š|ª0=Tapeisnotwrite *Š|®protected*Š|*Š|*Š|E*Š+-----------------------------------------‚1=TapeDrivenotready *¹**seenote*¶0=TapeDriveready*?*ˆ**Thisbitissetiftheinitialconfigureandmountcommand9*‹fromIOSfailsbecauseofabadparameterorattribute,9*‹andalsowhenaconfigureanddismountcommandwithall.*‹validparametersandattributesis‚received.*2*ˆIOSCTPgiveninCCBTYPEfieldofCCBforchannel***ˆIOSDTPisXDSTAPE($05)formagnetictape*;*ˆIOSDRCisIODMTA($06)fortheMTAdriver(newdefinition)**O**********************************************************************************ˆSubroutinescalled:LOGPHY**ˆEntry:/*’A1=pointertodrive'svariableblockinCCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D“*‚R*™A„R‚PˆP‚P**™P=parameterregister*™R=returnregister!*™*=savedandrestored‚register**ˆExit::*’A0=pointertoIOSATWfieldofusertask'sstatusblock1*’D6=physicaladdressofusertask'sconfigure/*—statusblock***ˆExitsto:)*’RTStoSTATCMD,orCONFGCOM,orDOCONFG*M*****************************************************************************M******************************************************************************STATCONFEQU‡*****E*ˆGetphysicaladdressofusertask'sconfigure/statusblockintoA0.6*ˆSubroutineLOGPHY‚convertsthelogicaladdressinD6=*ˆintoaphysicaladdressinD6.‚Thelengthoft6 heblockmust*ˆbesetupinD5.*ˆLOGPHY‚alsoexpects:*’A5=physicaladdressofCCB*’A0=thephysicaladdress3*•ofthetaskthatownsthestatusparameterblock.A*ˆLOGPHY‚abortsprocessingandreportsanerroriftheconfigure/>*ˆstatusblockthatwespecifyisnotentirelywithinamemory:*ˆsegmentthatbelongstothetaskthatallegedlyownsthe*ˆparameterblock.**;‰MOVE.L„IOSDBP(A4),D6‡D6<---logicaladdressofconfigure/*¦statusblock*‰MOVE.L„D5,-(SP)ŒSaveD55‰MOVE.L„#IOSMLN,D5ŠD5<---lengthofdrive'svariable&*¦block.‚LOGPHYsavesandrestoresD5.‰MOVE.L„CCBTASKA(A5),A0 ‰BSR.L…LOGPHY‰MOVE.L„(SP)+,D5ŒRestoreD5*5STATCON1MOVE.L„D6,A0EntrypointfromCONFGCOM,when"*¦wealreadyhavephysicaladdress!*¦ofusertask'sconfigure/status *¦blockinD6 *¦AlsoentrypointfromDOCONFG.****;*ˆFillinIOSDSTwithinformationabouttapedensity,write!*ˆprotection,andmountedstatus.*****ˆTapedensity**‰MOVE.B„TAPEDENS(A1),(A0)***ˆWriteprotection**‰TST.B…WRTPRT(A1) ‰IFˆƒTHEN“BSET†#XDSWPB,(A0)‰ELSE“BCLR†#XDSWPB,(A0)‰ENDI**3*ˆCapacityofsoftwaretochangetransportdensity.**‰TST.B…CNGDENS(A1) ‰IFˆƒTHEN“BSET†#XDSCGB,(A0)‰ELSE“BCLR†#XDSCGB,(A0)‰ENDI ***ˆMounted(ready)statusB*ˆNotethatweonlysetthisbitforIOSifwereceiveaconfigure;*ˆandmountcommandwithbadparameters,orifwereceivea6*ˆconfigureanddismountcommandwithgoodparameters.B*ˆThisallowsIOStosendalongcommandstousinallothercases.7*ˆThus,ifnotapewasmountedwhenthesystemcameup,5*ˆwecanlaterreceiveaconfigureandmountcommand.;*ˆWhenaconfigureandmountcommandexecutessuccessfully,:*ˆthatis,whenwecandeterminetapedensity,thenweset?*ˆanotherMOUNTEDflagandpermitreadsandwritestothetape.**‰TST.B…MOUNT1(A1) ‰IFˆƒTHEN“BSET†#XDSNRB,(A0)+‡notready‰ELSE“BCLR†#XDSNRB,(A0)+‡ready‰ENDI L1‡SET‡IOSDST****ˆSettheIOSCTP,IOSDTP,andIOSDRCfields.**‰MOVE.B„CCBTYPE(A5),(A0)+ L1‡SET‡IOSCTP*‰MOVE.B„#XDSTAPE,(A0)+ L1‡SET‡IOSDTP*‰MOVE.B„#IODMTA,(A0)+ L1‡SET‡IOSDRC****‰RTSG*********************************************************************** ‰PAGEN******************************************************************************N*********************************************************************************ˆDFCONFG--DEFAULTCONFIGURATIONROUTINE*:*ˆThisroutinesetsupregistersfortheCONFGCOM‚routine..*ˆIfwearedoingadefault‚configurecommand,-*ˆthenwearegoingtotransferconfiguration>*ˆattributesandparametersfromtheusertask'sconfiguration>*ˆparameterblock(pointedtobytheIOSDBPfieldoftheIOCB):*ˆtotheconfigureblockwhichispartofthedrive'sDCB.*9*ˆFirst,wefillintheIOSDSTthroughtheIOSPRMfields.;*ˆThen,wetransfertheIOSATWfieldthroughtheendofthe8*ˆconfigurationblockfromtheusertask'sconfiguration=*ˆblocktothedrive'svariableblock'scorrespondingfields.*=*ˆThisroutinesetsupA2topointtotheDCBMTC+IOSATWfield*ˆofthedrive'sDCB,?*ˆandputstheIOPRMNOTmaskfortheconfigurecommandintoD1.** *’IOCB DCB'*ˆA4--->+--------+‘A3--->+--------+ *|ˆ|™|ˆ| *|ˆ|™|ˆ| *|ˆ|™|ˆ|*+--------+™|ˆ|*|IOSDBP‚|---->+-------+Š|ˆ|*+--------+†|IOSDST|Š|ˆ|* |IOSCTP|Š|„.ƒ|**†fieldssetbydriver‚--->|IOSDTP|Š|„.ƒ|* |IOSDRC|Š|„.ƒ|* +-------|Š+--------+%* |IOSATW|‚A2--->|ˆ|DCBMTC+IOSATW* |‚.„|‚------>|ˆ|* |‚.„|Š|ˆ|* |‚.„|‚------>|ˆ|* |these‚|Š|ˆ|* |fields|‚------>|ˆ|* |copied|Š|ˆ|* |toDCB|‚------>|ˆ|* +-------+Š+--------+***ˆSubroutinescalled:*6*ˆEntry:„A1=pointertodrive'svariableblockinCCB*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB/*’A6=physicaladdressofTCBofattachedtask*6 *’D5=08*’D6=channeldevicenumberforthetapedrive(DCBCDV)*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D‡RˆR *™A‡P‚R‚P…P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister*A*ˆExit:…D1=maskofbitsthatcannotbesetbydefaultconfigure*’D5=21*’A2=pointer‚toIOSATWfieldofthedrive'sDCB***ˆExitsto:CONFGCOM*M*****************************************************************************M****************************************************************************** DFCONFG‚EQU‡***8*ˆGettheaddressoftheIOSATWfieldofthedrive'sDCB *ˆintoA2.**DFC010ƒEQU‡DCBMTC+IOSATW‰LEA‡DFC010(A3),A2***;*ˆSetupD5.Bwith2asaflagtoindicatetoCONFGCOMthat3*ˆwearecomingfromthedefaultconfigureroutine.** ‰MOVE.Bƒ#2,D5*‰BRA.S†CONFGCOMI*************************************************************************‰PAGEN******************************************************************************N******************************************************************************* *ˆCONFG--CONFIGURATIONROUTINE*:*ˆThisroutinesetsupregistersfortheCONFGCOM‚routine.6*ˆIfwearedoingaconfigurecommand,whetheritbea<*ˆconfigureandmountoraconfigureanddismountoraplain8*ˆconfigure,thenwearegoingtotransferconfiguration>*ˆattributesandparametersfromtheusertask'sconfiguration>*ˆparameterblock(pointedtobytheIOSDBPfieldoftheIOCB)>*ˆtotheconfigureblockwhichispartofthedrive'svariable*ˆblockoftheCCB.**ˆWesetupD5sothatonexit:7*’D5.B=1forconfigurebutneithermountnordismount*™0forconfigureandmount*˜-1forconfigureanddismount*8*ˆThen,wefillintheIOSDSTthroughtheIOSPRMfields.;*ˆNext,wetransfertheIOSATWfieldthroughtheendofthe8*ˆconfigurationblockfromtheusertask'sconfiguration=*ˆblocktothedrive'svariableblock'scorrespondingfields.*?*ˆThisroutinesetsupA2topointtotheCONFGBLK+IOSATWfield+*ˆofthedrive'svariableblockintheCCB.** *’IOCB CCB'*ˆA4--->+--------+‘A5--->+--------+ *|ˆ|™|ˆ| *|ˆ|™|ˆ| *|ˆ|™|ˆ|*+--------+™|ˆ|*|IOSDBP‚|---->+-------+Š|ˆ|)*+--------+†|IOSDST|‚A1--->+--------+* |IOSCTP|Š|„.ƒ|drive's3*†fieldssetbydriver‚--->|IOSDTP|Š|„.ƒ|variable* |IOSDRC|Š|„.ƒ|block* +-------|Š+--------+'* |IOSATW|‚A2--->|ˆ|CONFGBLK+IOSATW* |‚.„|‚------>|ˆ|* |‚.„|Š|ˆ|* |‚.„|‚------>|ˆ|* |these‚|Š|ˆ|* |fields|‚------>|ˆ|* |copied|Š|ˆ|* |toCCB|‚------>|ˆ|* +-------+Š+--------+***ˆSubroutinescalled:*6*ˆEntry:„A1=pointertodrive'svariableblockinCCB*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB/*’A6=physicaladdressofTCBofattachedtask**’D5=0*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D‡R‹R*™A‡P‚R‚P‚P‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister*5*ˆExit:…A1=pointertodrive'svariableblockinCCB<*’A2=pointer‚toIOSATWfieldofthedrive'svariableblock*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB/*’A6=physicaladdressofTCBofattachedtask'*’D1.B=statusvalueforerrorroutine4*’D5.B=1‚ifconfigure&neithermountnordismount*™0‚ifconfigure&mount*˜-1‚ifconfigure&dismount**ˆExitsto:CONFGCOM*M*****************************************************************************M*****************************************************************************%CONFG„EQU‡*“Entrypointforconfigure**8*ˆChecktheIOSOPTfieldoftheIOCBtoseeifwehavea<*ˆconfigureandmount,aconfigureanddismount,orneither,*ˆandsetD5sothat"*’D5=0foraconfigureandmount&*’D5=-1foraconfigureanddismount7*’D5=1foraconfigureandneithermountnordismount**‰MOVE.W„IOSOPT(A4),D7 0-‰IFˆD0‚ƒ#IOPMNTƒTHEN…It'snotaconfigure*°andmount*“BTST†#IOPDMNTB,D0ˆConfigureanddismount?!“IFˆ†THEN†Ifit'saconfigure*°anddismount,then*°subtract1fromD5. SUBQ.B„#1,D5“ELSEšOtherwise,ADDQ.B„#1,D5…add1toD5.“ENDI ‰ELSE¤It'saconfigureandmount“MOVEQB„ISTAMNT,D1'“TST.B…MOUNTED(A1)‰Ifatapeisalready'“BNE.L…CMDEXIT2Œmounted,it'sanerror. ‰ENDI*=*ˆGettheaddressoftheIOSATWfieldofthedrive'svariable*ˆblockintheCCBintoA2.**‰LEA‡CONFGBLK+IOSATW(A1),A2**<*ˆCopytheIOSRTOandIOSWTOfieldsfromtheDCBtotheCCB.<*ˆAconfigurecommandisnotallowedtochangethesefields;+*ˆonlyadefaultconfiguremaychangethem.*CONWTOƒEQU‡CONFGBLK+IOSWTO‰MOVE.L„DCBTMW(A3),CONWTO(A1)CONRTOƒEQU‡CONFGBLK+IOSRTO‰MOVE.L„DCBTMR(A3),CONRTO(A1)**8**‡BRA.L†CONFGCOM‹WenowfallintotheCONFGCOMroutine.J**************************************************************************‰PAGEN******************************************************************************N*******************************************************************************)*ˆCONFGCOM--COMMONCONFIGURATIONCHORES*O********************************************************************************8*ˆCONFIGURE/STATUSPARAMETERBLOCKFORMAGTAPEDRIVER*O*********************************************************************************”|-----------------|2*”|IOSDST|IOSCTP|ƒDevicestatus|ChannelType*”|-----------------|/*”|IOSDTP|IOSDRC|ƒDevicetype|DriverCode*”|-----------------|*”|IOSATMŠ|ƒAttributesmask*”|-----------------|(*„Bitnumbers…|IOSPRMŠ|ƒParametersMask*„inIOSPRM‡|-----------------|"*„field‹|IOSATWŠ|ƒAttributesWord*…--------‡|-----------------|#*ˆ0‹|IOSRECŠ|ƒVersadosRecordSize*”|-----------------|*ˆ1‹|IOSRSZŠ|ƒDeviceSize*”|---------|*”|‘|*”|-----------------|*ˆ2‹|IOSWTOŠ|*”|---------|*”|‘|*”|-----------------|*ˆ3‹|IOSRTOŠ|*”|---------|*”|‘|*”|-----------------|"*†4,5IOSDDC-->|IOSDEN|IOSRDT‚|*”|-----------------|*†6,7‹|IOSWRT|IOSERT‚|*”|-----------------|'*ˆ8‹|IOSRDTOŠ|ƒTimeoutforread,space*”|---------|*”|‘|*”|-----------------|1*ˆ9‹|IOSSPTOŠ|ƒTimeoutforspaceforward/reverse"*”|---------|ƒforfilemark*”|‘|*”|-----------------|#*‡$A‹|IOSRWTO‰|ƒTimeoutforrewind*”|---------|*”|‘|*”|-----------------|3*‡$B‹|IOSSRTO‰|ƒTimeoutforsearchforward/reverse"*”|---------|ƒforfilemark*”|‘|*”|-----------------|%*”|IOSMTSV‰|‚Reservedforfutureuse*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*”|‘|*”|-----------------|*>*ˆIOSDEN--densityrequestedbyuserforwritefromloadpoint*‹XDSD800=800bpi*‹XDSD1600=1600bpi4*ˆIOSRDT--numberofreadtriesbeforeerrorreport0*ˆIOSWRT--numberofwritetriesbeforeerasure2*ˆIOSERT--numberoferasuresbeforeerrorreport*C*ˆIOSMLN=lengthinbytesofaconfigure/statusblockformagtape*O*******************************************************************************>*ˆThisroutinedoestheworkfortheconfigurationanddefault=*ˆconfigurationcommandsthatdoesnotrequiredeviceaccess.*?*ˆOnentry,D5isaflagtotelluswhattypeofcommandweare *ˆprocessing.**>*ˆInthisroutine,wecheckthevalidityoftheattributesand<*ˆparametersthattheuserwishesto‚change,andiftheyare@*ˆvalid,wemovetheproposedconfigurationfromtheusertask's<*ˆconfigurationtotheconfigurationblockofeithertheDCB9*ˆ(foradefaultconfigure)ortheCCB(foraconfigure).*A*ˆIfthisisnotaconfigureandmountcommand,wedonotneedto*ˆaccessthedevice,@*ˆandsoweexitviaCMDEXIT3.‚Ifthisisaconfigureandmount,7 +*ˆwebranch‚toCONFG2tofinishprocessing.***ˆSubroutinescalled:STATCONF*6*ˆEntry:„A1=pointertodrive'svariableblockinCCB<*’A2=pointertoIOSATWfieldofthedrive'svariableblock*—(ifcomingfromconfigure)*—or7*—pointertoIOSATWfieldoftheconfigureblockinDCB$*—(ifcomingfromdefaultconfigure)*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB/*’A6=physicaladdressofTCBofattachedtask***’D5.B=**–-1ifcomingfromconfigureanddismount&*—0ifcomingfromconfigureandmount0*—1ifcomingfromconfigure&neithermountnor *™dismount$*—2ifcomingfromdefaultconfigure**"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6„7*™D„*‚*‚*‚R‚*‚P‚R*™A„R‚P‚P‚P‚P‚P***™P=parameterregister*™R=returnregister*™*=destroyedregister(*ˆExit:…A0=pointerto‚theIOSATWfield*—ofuser'sconfigureblock/*’A1=pointertodrive'svariableblockinCCB"*’A2=pointertotheIOSATWfield0*—oftheconfigureblockofthedriveintheCCB*—(ifcomingfromconfigure)*—or*—pointerto‚theIOSATWfield*—oftheconfigureblockinDCB$*—(ifcomingfromdefaultconfigure)*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB/*’A6=physicaladdressofTCBofattachedtask*&*’D3=ErrorcodeforexittoCNERROR14*’D6=Pointertousertask'sconfigure/statusblock**ˆExitsto:0*’CNERROR1ifanyerrorfoundinconfiguration's"*’attributemaskorparametermask.*’CMDEXIT1ifnoerrorsandthiswasadefault+*’configure,aconfigureanddismount,ora**’configureandneithermountnordismount.*’CONFG2ifnoerrorsandthiswasaconfigure*’andmount‚command*M*****************************************************************************M******************************************************************************CONFGCOMEQU‡***D*ˆBSR.StosubroutineSTATCONF.‚STATCONFfillsintheIOSDST,IOSCTP,?*ˆIOSDTP,andIOSDRCfieldsoftheusertask'sconfigure/status=*ˆparameterblockpointedtobytheIOSDBPfieldoftheIOCB,E*ˆandreturnswithA0pointingtotheIOSATMfieldoftheusertask's*ˆconfigure/statusblock.)*ˆSTATCONFdestroysD6,butpreservesD5.**‰BSR.L‡STATCONF*5*ˆOnreturnfromSTATCONF,A0pointstoIOSATMfield.4*’D6=pointertousertask'sconfigure/statusblock**‘+----------------+*ˆA0--->‚|IOSATM‰|*‘+----------------+*‘|IOSPRM‰|*‘+----------------+*?*ˆGettheusertask'sIOSATMfieldandIOSPRMfieldintoD0and:*ˆD2respectivelysothatwecandeterminetheirvalidity.**‰MOVE.W„(A0)+,D0‰MOVE.W„(A0)+,D2 L1‡SET‡IOSATM L1‡SET‡IOSPRM****‘+----------------+*ˆA0--->‚|IOSATW‰|*‘+----------------+*‘|IOSREC‰|*‘+----------------+*8*ˆWhenthedriverisfirstcalled,alltheconfiguration5*ˆinformationmustbewrittentothe‚drive'svariable**ˆblock,includingtheWTOandRTOvalues.*>*ˆForaconfigurecommand,theRTOandWTOvalueshavealready9*ˆbeencopiedfromtheDCBtothedrive'svariableblock.*A*ˆThefirstconfigurecommandattributesmaskandparametersmask<*ˆshouldcontainonlythosevalueschangeablebyanordinary*ˆconfigure.=*ˆAconfigurecommandisnotallowedtochangetheWTOorRTO *ˆvalues.***8*ˆMaskofbitsforparameterwordthatcanbechangedby)*ˆdefaultconfigurebutnotbyconfigure.**CON060ƒEQU‡1<ƒAND.B‚D5‚#2ƒTHENƒIt'snotthefirstcommand.*¸andit'saconfigure**9*ˆCheckforthefirsttypeoferror,namely,a8 ttributeor.*ˆparameterrecognizedbychangedefaultonly.**“MOVE.B„#CECCDO,D3**%*ˆCheckforparametersmasklegality.**'“MOVE.W„#CON070,D1ŠD1<---maskofbits*°recognizedbydefault*°butnotconfigure*°inIOSPRM.“AND.W…D2,D1“BNE.S‡CNERROR1**5*ˆSetupD1andD4tocheckforsecondtypeoferror,:*ˆnamely,changinganunrecognizedattributeorparameter,8*ˆorchanginganattributeorparameterthatcanonlybe+*ˆchangedbydefaultconfigurationcommand.**“MOVE.W„#IOPRMNOT!CON070,D1‰ENDI***ˆCheckparametersmask.**2‰MOVE.B„#CECUAP,D3ŠIftheuseristryingtochange+‰AND.W…D2,D1valuesthatwedon'trecognize$‰BNE.S‡CNERROR1Œthenitisanerror.***ˆCheckattributesmask.**‰AND.W…D0,D4‰BNE.S‡CNERROR1**/*ˆIfcontrolreachesthispoint,thenD1.W=0.***D*ˆSettheIOSATWfieldintheusertask'sconfigureblocktoreflect?*ˆthefinalattributesthatwillbeineffectwiththeproposedC*ˆconfiguration.‚Wecomputethisfinalattributevaluebycombining>*ˆtheattributebitsthattheusertaskisspecifyingwiththe:*ˆvaluesoftheremainingattributebitsfromtheexisting*ˆconfiguration.**4CON100ƒAND.W…D0,(A0)MaskoutthebitsoftheIOSATW *¦thattheuserdoesnotwishto *¦change.*&‰NOT.W…D0’ComplementD0sothatitnow*¦holdsthebitsthattheuser*¦doesnotwishtochange.**‰AND.W…(A2)+,D0ŒD0nowholdsthosebitsof*¦thecurrentconfiguration"*¦thatwillberetainedinthenew,‰OR.W†D0,(A0)TheIOSATWfieldoftheuser's*¦configureblocknowholdsthe#*¦totalproposednewconfiguration. L1‡SET‡IOSATW*****ˆCheckthe‚IOSATWword,and8*ˆsetorcleartheREQDENSfield‚ofthedrive'svariable*ˆblock.***‰MOVE.W„(A0)+,D0–MovetheIOSATWwordinto*°D0tomakeiteasiertotest,*°andalsoadvanceA0topoint*°totheIOSRECfield.‰BTSTW…#IOSREQB,D0,‰SNE‡REQDENS(A1)‰SettheREQDENSflagifthe*°userisrequestingadensity*°andclearitiftheuseris*°notrequestingadensity.***F*ˆNowwewanttoprocesstheparameterfields.‚Foranyparameterfield?*ˆthattheusertaskisnotspecifying,we'llcopytheexisting>*ˆconfigurationvalueintotheusertask'sconfigureparameter:*ˆblock.‚Theresultingmergedparametervaluesthatendup?*ˆintheusertask'sconfigurationparameterblockwillreflect1*ˆthetotalconfigurationthatisbeingproposed.*=*ˆRecallthatD1.W=0fromabove.‚WealsohaveD2.W=IOSPRM1*ˆfromtheusertask'sconfigureparameterblock.*;*ˆAdditionally,wehaveA0=loc(IOSREC)intheusertask'sD*ˆconfigurationparameterblock,andwehaveA2=loc(IOSREC)inthe(*ˆconfigureblockthatisbeingupdated.**”USERTASKBLOCKBEINGUPDATED&*‘+----------------+‹+---------------+'*ˆA0--->‚|IOSREC‰|ƒA2--->|IOSRECˆ|&*‘+----------------+‹+---------------+*‘|IOSRSZ‰|‹|IOSRSZˆ|&*‘+--------+‹+--------+ *‘||‹||&*‘+----------------+‹+---------------+*D*ˆWewillnowbranchintotheloopthatmergestheparametervalues.A*ˆForfieldsthattheuserhasnotspecified,wecopythecurrent=*ˆconfigurationparametersintotheuserconfigurationblock.B*ˆThenwewillbereadytocheckthetotalproposedconfiguration.*3*ˆD1.WisusedasanindexintotheCONFGLENtable.<*ˆEachentryintheCONFGLENtablegivesusavalueequalto9*ˆN-1,whereNisthenumberofbytesofthecorresponding*ˆparameterfield.4*ˆTheendoftableismarkedbya-1sentinelvalue.=*ˆWeneedthistablebecausetheparameterfieldsarenotall7*ˆthesamelength,andwemovedataonebyteatatime.** ‰BRA.S†CON200>‰PAGE†########################################################K*****************************************************************************ˆCONFIGURATIONLENGTHTABLE*<*ˆThistabledefinesthelengthofeachparameterfieldinaA*ˆconfigureblockforamagtapedrive.‚ThereisoneentryintheG*ˆCONFGLENtableforeachparameterfield8 inaconfigureblock,andtheC*ˆvalueofatableentryisN-1whereNisthelength(inbytes)of$*ˆthecorrespondingparameterfield.**M******************************************************************************CONFGLENEQU‡*)‰DC.B†IOSRSZ-IOSREC-1…LengthofIOSREC-1)‰DC.B†IOSWTO-IOSRSZ-1…LengthofIOSRSZ-1)‰DC.B†IOSRTO-IOSWTO-1…LengthofIOSWTO-1)‰DC.B†IOSDEN-IOSRTO-1…LengthofIOSRTO-1)‰DC.B†IOSRDT-IOSDEN-1…LengthofIOSDEN-1)‰DC.B†IOSWRT-IOSRDT-1…LengthofIOSRDT-1)‰DC.B†IOSERT-IOSWRT-1…LengthofIOSWRT-1*‰DC.B†IOSRDTO-IOSERT-1„LengthofIOSERT-1,‰DC.B†IOSSPTO-IOSRDTO-1ƒLengthofIOSRDTO-1,‰DC.B†IOSRWTO-IOSSPTO-1ƒLengthofIOSSPTO-1,‰DC.B†IOSSRTO-IOSRWTO-1ƒLengthofIOSRWTO-1,‰DC.B†IOSMTSV-IOSSRTO-1„LengthofIOSSRTO-1‰DC.B†-1’Endoftableflag****ˆAlignlocationcountertowordboundary.**‰DS.W†0**@*ˆThisloop,whichisenteredatCON200,processestheparameter *ˆfields.*H*ˆWerotateD2tobringthebitinquestiontobit15whereitiseasily *ˆtested.<*ˆIftheparametermaskbitisnotset,thentheuserisnot?*ˆspecifyingthisparametervalue,andsowecopytheparameter@*ˆfromtheexistingconfigurationintotheusertask'sconfigure*ˆparameterblock.**7CON120ƒROR.W…#1,D2RotateD2toputthebitinquestion*¦intoposition15CON130ƒTST.W…D2)*¦Ifthebitisset,thenwedonotcopy.-‰BMI‡CON140ŽIfthebitisnotset,thencopy.‰MOVE.B„(A2),(A0)CON200ƒMOVE.B„CONFGLEN(PC,D1.W),D0ŠPuttheentryintableinto*°D0. ‰EXT.W…D0!‰BGE‡CON120ŽGoaroundouterloop.**?*ˆNoticethatA0pointstotheIOSMTSVfieldoftheusertask's@*ˆconfigureparameterblockwhencontrolfallsoutofthisloop.<*ˆSimilarly,A2pointstotheIOSMTSVfieldoftheconfigure4*ˆblockfortheconfigurationthatisbeingupdated.**”USERTASKBLOCKBEINGUPDATED&*‘+----------------+‹+---------------+)*ˆA0--->‚|IOSMTSVˆ|ƒA2--->|IOSMTSV‡|&*‘+----------------+‹+---------------+ *‘||‹||&*‘+----------------+‹+---------------+ *‘||‹||&*‘+----------------+‹+---------------+*G*ˆNowwewanttochecktheproposedconfigurationtoseeifitcontains3*ˆanyinvalidorinconsistentconfigurationvalues.;*ˆIfitdoes,we'llabortwithanappropriateerrorreport.****2*ˆChecktoseethattheproposeddensityislegal.4*ˆTherecognizeddensitiesareXDSD1600andXDSD800.**‰MOVE.B„IOSDEN-IOSMTSV(A0),D0‰IF.B†D0‚‚#XDSD1600“AND.B“D0‚‚#XDSD800ƒTHEN“MOVE.B„#CECDEN,D3CNERROR1‹BRA.S†CONERROR‰ENDI *;*%%%%%%%%%%%%%ƒBWN12/7/84‚Changetheorderofdoingthings@*ˆSinceweareupdatinghere,theoffsetstoA0arexxxx-IOSMTSV*ˆinsteadofxxxx-IOSATW**@*ˆTheIOSRDTfieldtellsushowmanytimesweshouldtrytoread>*ˆbeforedeclaringanerror,andtheIOSWRTfieldtellsushow*ˆmanytimesweshouldwrite.9*ˆA0ineitherfieldisequivalenttoa1inthatfield.?*ˆChecktoseethatIOSRDTandIOSWRTareatleast1.Ifeither)*ˆis0,setitto1intheupdatedblock.***‰TST.B…IOSRDT-IOSMTSV(A0) ‰IFˆ†THEN“MOVE.B„#1,IOSRDT-IOSMTSV(A0)‰ENDI*‰TST.B…IOSWRT-IOSMTSV(A0) ‰IFˆ†THEN“MOVE.B„#1,IOSWRT-IOSMTSV(A0)‰ENDI*#*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%**>*ˆNowwearereadytocopytheproposedconfigurationfromthe>*ˆusertask'sconfigureblockintotheconfigureblockthatis*ˆbeingupdated.5*ˆForaconfigurecommand,we'reupdatingthecurrent7*ˆconfigureblockinthedrive'sareaoftheCCB,while<*ˆforadefaultconfigurecommandwe'reupdatingthedefault%*ˆconfigureblockinthedrive'sDCB.>*ˆNoticethatwecopytheIOSATWandalltheparameterfields,;*ˆbutwedon'tcopythemaskfieldsbecausethemaskfields7*ˆaren'treallypartofthetotaldeviceconfigurati9 on.**‰MOVEQ…#IOSMTSV-IOSATW-1,D0CON400ƒMOVE.B„-(A0),-(A2)‰DBRA†D0,CON400**”USERTASK‘BLOCKNOWUPDATED&*‘+----------------+‹+---------------+'*ˆA0--->‚|IOSATW‰|ƒA2--->|IOSATWˆ|&*‘+----------------+‹+---------------+*‘|IOSREC‰|‹|IOSRECˆ|&*‘+----------------+‹+---------------+*?*ˆAtthispoint,A2pointstotheIOSATWfieldoftheconfigure*ˆblockthat'sbeingupdated.:*ˆIfthiswasaconfigureandmount,thenwehavetogoto8*ˆCONFG2tocompleteprocessingunderinterruptcontrol.*ˆOtherwise,wegotoCMDEXIT1.)*ˆRecallthatD5=2ifdefaultconfigure*”D5=0ifconfigureandmount#*”D5=-1ifconfigureanddismount5*”D5=1ifconfigureandneithermoountnordismount* ‰TST.B…D5&‰IFˆ†THENIt'saconfigure&mount0“MOVE.L„D6,CONBLOCK(A1)…Savephysicaladdressof*°usertask'sconfigure/*°statusblock.D*ˆSettheMOUNT1flagsoIOSwillknowwereceivedavalidconfigure *ˆcommand.**“ST.B†MOUNT1(A1) “BRA.S†CONFG2‰ENDI+‰IFˆ†THEN†It'saconfigureanddismount**?*ˆIfit'saconfigureanddismount,thenclearthemountedflag,B*ˆsettheDCBCCFflagtoindicatethattheoperatingsystemshould9*ˆreturnthedrivetoitsdefaultconfiguration,andcall>*ˆSTATCON1toupdateIOSDST.‚Wecanenterthe‚STATCONFroutine'*ˆattheSTATCON1entry‚becausewehave4*’D6=pointertousertask'sconfigure/statusblock**“SF.B†MOUNT1(A1)“SF.B†MOUNTED(A1)*“ST.B†DCBCCF(A3) “BSR.L‡STATCON1‰ENDI‰BRA.L†CMDEXIT1H************************************************************************‰PAGEN******************************************************************************N*******************************************************************************)*ˆCONERROR--CONFIGURATIONERRORROUTINE*=*ˆControlcomestothisroutinewhenitisnecessarytoabort4*ˆwithanerrorcodefromanyconfigurationcommand.4*ˆErrorcodesintherange$01to$3Fareuniversal.3*ˆErrorcodesintherange$40to$7Fareuniqueto*ˆthisdriver.***ˆSubroutinescalled:*!*ˆEntry:„D3=detailederrorcode6*’D6=physicaladdressofusertask'sconfigureblock*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™D‡R…PˆP*™A„***™P=parameterregister*™R=returnregister*™*=destroyedregister***ˆExit:…D1.B=configurationerrormessage**ˆExitsto:CMDEXIT2*M*****************************************************************************M***************************************************************************** CONERROREQU‡*2‰MOVE.LƒD6,A0’Putthedetailederrorcodeinto‚the5‰MOVE.BƒD3,IOSDST(A0)ˆIOSDSTƒfieldƒofƒthe‚user‚task's9‰MOVEQBƒISTACNF,D1‹configureparameterblock,andthen‚go6‰BRA.L„CMDEXIT2to‚thecommandprocessor'scommonexit(*¦routinewithD1.Bsetuptoreport‚the#*¦majorƒerror‚code‚that‚indicates‚a*¦configurationerror. $*¨Noticethatwedon't‚need‚to‚worry)*¦aboutcleaningupthestackbecausethe)*¦commonexitroutinecleansupthestack!*¦byrestoringthestackpointer.O******************************************************************************* ‰PAGEN******************************************************************************N*******************************************************************************$*ˆRDWRTCMD,COMMCMD,CONFG2ROUTINES*/*ˆTherearethreeentrypointstothisroutine.*.*’(1)RDWRTCMDistheentrypointfortheread)*–forwardandwriteforwardcommandsthat0*–needtocheckMOUNTEDandalsoneedtocompute*–addressesfortheI/Obuffer*6*’(2)COMMCMDistheentrypointforthecommandsthat1*–needtocheckMOUNTEDbutdon'tneedtocompute*–addressesfortheI/Obuffer.*5*’(3)CONFG2istheentrypointfortheconfigureand6*–mountcommand,whichdoesnotneedtocheckMOUNTED,6*–andwhichdoesnotneedtocomputeaddressesforthe *–I/Obuffer.***#*ˆSubroutinescalled:LOGPHY,MTINT*6*ˆEntry:„A1=pointerto9 drive'svariableblockinCCB*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB9*’A6=physicaladdressoftheTCBthatcontrolsthetask*’D5=0*’D6=channeldevicenumber**"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚R‹P‚P*™A„*‚P…P‚P‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister*(*ˆExit:…D1.B=errorcode/statusvalue*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB/*’A6=physicaladdressofTCBofattachedtask*2*ˆExitsto:CMDEXIT3‚orCMDEXIT2incaseoferror.*M*****************************************************************************M*******************************************************************************?*ˆIfenteringwithareadorawritecommand,subtractonefromD*ˆD5asaflagtotellusthatweneedtocomputethebufferaddress *ˆandlength.**RDWRTCMDEQU‡* ‰SUBQ.B„#1,D5**A*ˆIfthisisanytypeofcommandexceptaconfigurecommand,then?*ˆwechecktheMOUNTEDflag.‚IfthedeviceisnotMOUNTED,then:*ˆitstapedensityisunknown,andwewillnotexecuteany%*ˆcommandsexceptconfigurecommands.** COMMCMD‚EQU‡*‰MOVEQB„ISTADNM,D1‰TST.B…MOUNTED(A1)‰BEQ.L…CMDEXIT2**1*ˆThisistheentrypointforconfigurecommands.**CONFG2ƒEQU‡***E*ˆPointA2tothewordimmediatelyfollowingthelastwordoftheI/OB*ˆpacketinthedriv'sareaofthedrive-associatedportionoftheA*ˆCCB.‚We'lluseA2withauto-decrementaddressingtofillinthe<*ˆI/OvaluesthatdescribetheI/Otransactionthatisbeing*ˆrequested.*)*ˆ**************WARNING****************H*ˆBecauseweuseauto-decrementaddressing,theorderinwhichthefieldG*ˆoftheI/Opacketaredefinedmustnotbealteredwithoutconsidering*ˆthisroutine.**‰LEA‡IOPKTEND(A1),A2**?*ˆPointA0tothe‚TCBthatcontrolsthetaskthatownstheIOCB=*ˆfortheI/Ocommandthatisbeingprocessed.‚IfthecommandE*ˆthatisbeingprocessedisanordinarycommandthatrequiresanI/O?*ˆbuffer,thetaskthatownstheIOCBalsoownstheI/Obuffer.**‰MOVE.L„CCBTASKA(A5),A0**=*ˆCopytheI/OoptionsfieldintotheIOOPTSfieldoftheI/O?*ˆpacket.‚Ifthesignbitoftheoptionsfieldisset,thenthe?*ˆIOCBincludesanIOSTSKandanIOSSESfield.‚ThesefieldscanG*ˆbeusedbyasystemtasktospecifythetaskthatownstheI/Obuffer8*ˆwhenthattaskisn'tthesametaskthatownstheIOCB.**‰MOVE.W„IOSOPT(A4),-(A2) L1‡SET‡IOOPTS‰BPL‡RDW025**B*ˆThissectioniscodeisonlyexecutedwhentheIOCBincludesthe$*ˆoptionalIOSTSKandIOSSESfields.A*ˆWeneedtogetapointertotheTCBthatcontrolsthetaskthat*ˆownsthebuffer.)*ˆTheT0GETTCBexecutiverequestexpects:**’A0=pointertotheIOSTSK/IOSSESpacket**ˆTheT0GETTCBexecutiverequestdestroys: *’A1,D0,D1,D2)*ˆTheTOGETTCBexecutiverequestreturns:)*’A0=pointertoTCBthatownsthetask.<*ˆControlreturnsfromtheT0GETTCBexecutiverequesttothe>*ˆinstructionimmediatelyfollowingtheTRAPinstructionifno*ˆerrorsaredetected.**“LEA‡IOSTSK(A4),A0“MOVE.L„A1,-(SP)“MOVE.L„#T0GETTCB,D0“TRAP†#EXEC “BRA.S†RDW020**=*ˆControlreturnsfromtheT0GETTCBexecutiverequesttothis=*ˆpointifthespecifiedtaskdoesn'texist.‚Inthiscase,we?*ˆreportanerrorindicatingthatthespecificationfortheI/O<*ˆbufferisbad.‚Wedon'tneedtocleanupthestackbecause!*ˆtheerrorroutinecleansitup.**RDW010BRA.L…BADBUFAD RDW020**@*ˆRestoreA1topointtothedrive'sareaofthedrive'sareaof**ˆthedrive-associatedportionoftheCCB.**‰MOVE.L„(SP)+,A1**;*ˆWhencontrolreachesthispoint,theregistersaresetas *ˆfollows:*!*ˆA6=loc(TCBofattachedtask)*ˆA5=loc(CCB)*ˆA4=loc(IOCB)*ˆA3=loc(DCB)@*ˆA2=loc(IOOPTSfieldofI/Opacketindrive'svariablebloc: k))*ˆA1=loc(drive'svariableblockinCCB):*ˆA0=loc(TCBoftaskthatownstheI/Obuffer)ifthere*isanI/Obuffer9*loc(TCBoftaskthatownstheIOCB)ifthereisnoI/O*buffer*8*ˆD5.B=-1ifweareprocessingareadorwritecommand/*0ifweareprocessingacommandotherthana*’readorwrite*;*ˆIfthisisareadorwritecommand,thengetthephysical5*ˆaddressoftheI/ObufferintoD6bycallingLOGPHY*ˆLOGPHYexpects: *’D6=logicaladdressofbuffer *’D5=lengthofbufferinbytes1*’A0=pointertoTCBthatcontrolsthetaskthat*—ownsthebuffer*ˆLOGPHYreturns: *’D6=buffer'sphysicaladdress**ˆLOGPHYpreservesD5andA0.*E*ˆIfthespecifiedbufferdoesnotresidewithinthespecifiedtask's=*ˆmemoryarea,subroutineLOGPHYabortswithanerrorreport.A*ˆLOGPHYalsoabortswithanerrorreportifthebufferlengthis*ˆzerooranoddnumber.**RDW025ƒEQU‡* ‰TST.B…D5 ‰IFˆ†THEN“MOVE.L„IOSSAD(A4),D6“MOVE.L„IOSEAD(A4),D5“SUB.L…D6,D5 “ADDQ.L„#1,D5 “BSR.L…LOGPHY‰ENDI**1*ˆPutthelengthoftheI/ObufferintoIOBUFLEN.@*ˆThencopyD6intoD5sothatwecanfillinfivefieldsofthe6*ˆdrive'sI/OpacketatoncewithaMOVEMinstruction.<*ˆRecallthatthefieldsintheI/Opacketareintheorder:*‰D5--->‚IOBUFLOC*‰D6--->‚IOBUFPTR*‰A0--->‚IOBUFTCB*‰A3--->‚DCBPNTR*‰A4--->‚IOCBPTR*‰A2--->‚IOOPTS*)*ˆAndA2ispointingtotheIOOPTSfield.**‰MOVE.L„D5,IOBUFLEN(A1) ‰MOVE.L„D6,D5RDW030ƒREG‡A4/A3/A0/D6/D5‰MOVEM.LƒRDW030,-(A2)L1‡SET‡IOCBPTRL1‡SET‡DCBPNTRL1‡SET‡IOBUFTCBL1‡SET‡IOBUFPTRL1‡SET‡IOBUFLOC**7*ˆIncrementtheTCBIOCNTfieldoftheTCBthatcontrols8*ˆthetaskthatownstheI/Obuffer(ortheIOCBinthe3*ˆcaseofaconfigurecommand).‚TheTCBIOCNTfield:*ˆofatask'sTCBindicateshowmanyI/Orequeststhetask1*ˆhaspendingcompletionunderinterruptcontrol.**‰ADD.B…#1,TCBIOCNT(A0)**:*ˆSavethevalueoftheSR,andtheninhibitinterruptsat9*ˆthemagtapechannel'sinterruptlevel.‚Weareaboutto4*ˆaltertheIOQUEUE,andwedon'twanttheinterrupt?*ˆhandlertoaccessthequeuewhilewearetryingtochangeit.**‰MOVE.W„SR,-(SP)‰INHIB**H*ˆPutthepointertothedrive'sareaoftheCCBintothenextavailableG*ˆqueueentry,andadvancethequeuepointer.‚WeknowwecanaccumulateD*ˆnomorethanonequeueentryforeachdrive,sowedon'tcheckfor*ˆoverflow.***,‰LEA‡IOQCNT(A5),A0‘A0<---addressofIOQCNT*‰MOVE.W„(A0),D0—D0<---contentsofIOQCNT"‰MOVE.L„A1,IOQUEUE-IOQCNT(A0,D0.W)‰ADD.W…#4,(A0)**A*ˆIfthequeuewasn'temptybeforewemadethelatestentry,then=*ˆsomecommandisbeingprocessedunderinterruptcontroland?*ˆthislatestcommandwillbeprocessedwhenitsturncomesup.=*ˆIfthequeuewasempty,thenwecallMTINTasasubroutine.** ‰TST.W…D0 ‰IFˆ†THEN**;*ˆPuttheaddressofPROCQUEintoINTSWTCH,andpointA0to=*ˆthedrive'smemory-mappedI/Oarea.‚Themachine'sinterrupt<*ˆlevelisthesamethatitwouldbeiftherewereanactualA*ˆinterruptfromtheMVME435board,sotheinterrupthandlerwill*ˆperformcorrectly.*G*ˆAlso,thefirsttimethatthereisaBSR.StoINTRTNintheinterrupt@*ˆhandler,controlwillreturnherewhenINTRTNexecutesanRTS.*“LEA‡PROCQUE(PC),A0“MOVE.L„A0,INTSWTCH(A5)“MOVE.L„CCBCHB(A5),A0“BSR.L…MTINT‰ENDI**A*ˆRestoretheSR,andtransfercontroltothecommandprocessor's:*ˆexitroutine.‚Wedon'tqueueanI/Ocompletioneventyet;*ˆbecausetheI/Otransactionwillbecompletedlaterunder*ˆinterruptcontrol.**‰MOVE.W„(SP)+,SR‰BRA.L…CMDEXIT3H************************************************************************ ‰PAGEN****************************************************************************** N********************************************************************************ˆHALTCMD--IOHALTCOMM: AND*A*ˆThisroutineimplementstheIOHALTcommandwhichisaninitiate*ˆIOtypecommand.*D*ˆWhenwereceivethiscommand,ifthereareentriesintheIOQUEUE,B*ˆthenwearewaitingforacommandtotheMVME435tobecompleted*ˆunderinterruptcontrol.*G*ˆThereasonwegotthiscommandismostlikelybecauseofatimeout--B*ˆourI/Oistakingtoolong.‚Itmaybethatthetransportwasput*ˆoffline.*B*ˆFirstwesearchtheIOQUEUEtoseeifthedrive'svariableblock<*ˆaddressmatchesanaddressintheIOQUEUE.‚Ifnot,thenwe8*ˆreturnwithazerovalueinD1throughHALTEXIT,which!*ˆqueuesahaltcompletionevent.*D*ˆIfwefindthedrive'svariableblockaddressintheIOQUEUE,then=*ˆwe‚removethatentryfromtheIOQUEUEanddecrementIOQCNT,A*ˆthenumberofbytesintheIOQUEUE,anddecrementtheTCBIOCNT.*C*ˆWechecktoseeifthedrive'svariableblockwasthefrontentry=*ˆoftheIOQUEUE.‚Ifthedrive'svariableblockwasthefront=*ˆentryoftheIOQUEUE,thenitiscurrentlybeingprocessed.?*ˆInthiscaseweresettheformattertostopanyactiononthe7*ˆtapedrive.IfthereareentriesleftintheIOQUEUE,C*ˆwemovethePROCQUEaddressintoINTSWTCH,Puttheaddressofthe4*ˆmemory-mappedIOareaintoA0,andBSR.StoMTINT.A*ˆIftherearenomoreentriesintheIOQUEUE,thenweputMTIDLE*ˆintoINTSWTCH.*:*ˆFinally,werestorethestatusregister,putthetimeout&*ˆmessageintoD1,andgotoHALTEXIT.****ˆSubroutinescalled:MTINT**ˆEntry:/*’A1=pointertodrive'svariableblockinCCB*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB5*’A6=physicaladdressofTCBthatcontrolsthetask**’D5=0*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚*‹P‚P*™A„*‚P‚*‚P‚P‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:/*’A1=pointertodrive'svariableblockinCCB*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB5*’A6=physicaladdressofTCBthatcontrolsthetask**’D1=statusvalue*’D5=0**ˆExitsto:‚HALTEXIT*M*****************************************************************************M****************************************************************************** HALTCMD‚EQU‡***>*ˆFirstsavethestatusregisterandinhibitinterruptsatour:*ˆlevel.‚WearegoingtobelookingattheIOQUEUE,andwe?*ˆdon'twanttheIOQUEUEtobechangedbytheinterrupthandler*ˆwhileweareexaminingit.**‰MOVE.W„SR,-(SP)‰INHIB**A*ˆSearchtheIOQUEUEforanaddressequaltotheoneinA1,which@*ˆistheaddressofthedrive'svariableblockforthiscommand.***‰LEA‡IOQUEUE(A5),A2.‰MOVE.W„#0,D0D0isusedasacounterandflag*6‰MOVE.W„IOQCNT(A5),D1‡IOQCNTholdsthenumberofbytes*¦intheactiveentriesinthe*¦IOQUEUE,andisthereforea*¦multipleoffour.**‰WHILE…‡DO“CMPA.L„(A2)+,A1“BEQ.S‡HALTFND “ADDQ.W„#4,D0 “SUBQ.W„#4,D1‰ENDW**<*ˆIftheaddressofthedrive'svariableblockisnotintheB*ˆIOQUEUE,thenrestorethestatusregisterandbranchtoHALTEXIT*;*ˆHALTEXITqueuesanIOHALTeventwithastatuscodeinD1.>*ˆSinceD1=0atthistime,thiswillindicatethattherewas,*ˆnoIOpendingforthisdriveatthistime.*‰MOVE.W„(SP)+,SR‰BRA.S†HALTEXIT** HALTFND‚EQU***ˆControlcomestoHALTFNDif>*ˆtheaddressofthedrive'svariableblockisintheIOQUEUE.*.*ˆFirstweremovethisentryfromtheIOQUEUE.*?*ˆWhenwestartthewhileloop,A2pointstothetheentryjust&*ˆfollowingtheonewewanttoremove.**’beforeMOVE.Lƒ(A2)+,-8(A2)**’+-------------------+,*’|…address1…|<---„Entrywewanttoremove*’+-------------------+*ˆA2--->ƒ|…address2…|*’+-------------------+*’|…address3…|*’+-------------------+**’afterMOVE.Lƒ(A2)+,-8(A2)**’+-------------------+; *’|…address2…|*’+-------------------+*’|…address2…|*’+-------------------+*ˆA2--->ƒ|…address3…|*’+-------------------+**“SUBQ.W„#4,D1D1<---numberofbytesthat*°liebelowtheaddresswe*°abouttoremovefromthe *°IOQUEUE.*!“WHILE…†DO‹MovequeueentriesMOVE.L„(A2)+,-8(A2)ˆup. SUBQ.W„#4,D1“ENDW*2“SUBQ.W„#4,IOQCNT(A5)‡Decrementnumberofbytesin *°IOQUEUE.**“MOVE.L„IOBUFTCB(A1),A0…DecrementTCBIOCNT“SUBQ.B„#1,TCBIOCNT(A0)**;*ˆAtthispointwehaveremovedtheentryfromtheIOQUEUE.=*ˆIfthiswasthefrontentry,wehavesomeextraworktodo,)*ˆbecausethisdrivewasdoingsomething.**,‰TST.W…D0’D0=0ifthiswasthefrontentry ‰IFˆ†THEN2“MOVE.L„CCBCHB(A5),A0‡A0<--memory-mappedIOarea:“MOVE.B„#FORDISCD,DSCMD(A0)Resetformattertostopaction5“MOVE.B„#MTARSTCD,DSCMD(A0)ResetMVME435tokillany *°interrupts.-“SF.B†REWFLAG(A1)‰Clearrewindflagincasea*°rewindcommandwashalted. *%%%%%%%%%%ƒbwn‚5/29/84.*’SF.B†TIMEFLAG(A5)ˆCleartimeoutflagincase*°onewassetupforthis *°command.**>*ˆIfthereareentriesleftintheIOQUEUE,thenwemuststart*ˆprocessingthenextentry.**“TST.W…IOQCNT(A5) “IFˆ†THEN*LEA‡PROCQUE(PC),A2MOVE.L„A2,INTSWTCH(A5)**;*ˆNotethatD0=0whenweBSR.StoMTINT,andthatflagis*ˆcheckedinMTINT.**BSR.L…MTINT“ELSE**<*ˆIfthereisnoentryleftintheIOQUEUE,thenwewillput;*ˆMTIDLEintoINTSWTCH.‚Thenifanyspuriousinterruptsare(*ˆreceived,wewillsetthedevicedown.*LEA‡MTIDLE(PC),A2MOVE.L„A2,INTSWTCH(A5)“ENDI‰ENDI*‰MOVE.B„#ISTATO,D1‰MOVE.W„(SP)+,SR‰BRA.S†HALTEXIT*L**************************************************************************** ‰PAGEN******************************************************************************N*******************************************************************************(*ˆLOGICALTOPHYSICALADDRESSCONVERSION*D*ˆGivenaphysicalTCBaddressandthelogicaladdressandlengthofC*ˆamemoryarea,subroutineLOGPHYcomputesthephysicaladdressofD*ˆthememoryarea.‚ItalsocheckstomakesurethatthegivenmemoryE*ˆareareallybelongstothetaskthatiscontrolledbythespecified*ˆTCB.***ˆIndetail:*%*’(1)Saveworkingregistersonstack5*’(2)Ifspecifiedmemoryareabeginsatoddaddress,**–oriflengthofmemoryareaiszero,put*–ISTAADDintoD15*’(3)OtherwisesetD0=#TOLOGPHYexecutiverequest.*’(4)Doatrapto#EXEC.,*’(5)Ifnotsuccessful,putISTAADDintoD1#*’(6)Restoreregistersandreturn.***ˆSubroutinescalled:Trapcall*@*ˆEntry:„A0=physicaladdressoftheTCBthatcontrolsthetask,*—thatownstheIOCBforthecommandthatis4*—currentlybeingprocessed,orthephysicaladdress7*—oftheTCBofthetaskthatownsthebufferforaread*—orawritecommand.;*’D6=logicaladdressofthefirstwordofthememoryarea)*’D5=lengthinbytesofthememoryarea*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚*‚*‚*‚*‚P‚PR**™A„PŽP**™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister*/*ˆExit:…D5=lengthinbytesofthememoryarea7*’D6=physicaladdressofthefirstwordofthememory*—area*"*ˆExitsto:RTStocallingroutine**’orBRA.StoCMDEXIT2ifthereisanerror*M*****************************************************************************M***************************************************************************** LOGPHYƒEQU‡* @‰MOVEM.L‚D0-D5/D7/A0,-(SP)†Savetheworkingregistersbypushing'*¦themontothestack.‚Wedon'tuse‚all&*¦of‚these‚registers‚directly,butthe)*¦T0LOGPHYexecutiveroutinedestroysthe*¦onesthatwedon'tuse.-‰PAGEš#######################################3‰MOVE.WƒD6,CCR‘Checktoseeifthespecified‚memory.‰BCS†LOG040area‚begins‚at‚an‚odd‚address,and&*¦abortifitdoes.‚Wewant‚the‚memory#*¦ar; ea‚to‚start‚on‚a‚word‚boundary.)*¦Noticethatwecheckforanoddaddress'*¦by‚copying‚bit0oftheaddressvalue*¦intotheCbitoftheCCR. /‰TST.L„D5•Abortprocessingifthelengthofthe4‰BEQ.S„LOG040specifiedmemoryareaiszero.‚Azero-$*¦lengthmemoryareaismeaningless. :‰MOVE.LƒTCBTST(A0),A0ŠGetthephysicaladdressofthe‚Task:‰MOVE.Lƒ#T0LOGPHY,D0‰Segment‚Table‚forthegiventaskinto/‰TRAP…#EXECA0,anduse‚an‚executive‚request‚to'*¦perform‚the‚conversionfromalogical *¦addresstoaphysicaladdress. 3‰BRA.S„LOG050’Controlreturnsfromtheexecutiveto'*¦this‚point‚iftheconversionwasgood'*¦andthespecifiedmemory‚area‚resides'*¦entirely‚within‚amemorysegmentthat$*¦belongsto‚the‚specified‚task.ƒThe(*¦physical‚addressofthememoryareais(*¦inD6,sowe'realmostreadyto‚return$*¦control‚to‚the‚routine‚that‚called*¦subroutineLOGPHY. *‰NOPControlreturnsfromtheexecutiveto)*¦thispointifthespecifiedmemoryarea#*¦is‚partially‚insideƒandƒpartially'*¦outside‚a‚memorysegmentthatbelongs(*¦tothespecifiedtask.‚Inthiscasewe*¦wanttoreportanerror. >LOG040„MOVEQBƒISTAADD,D1Controlreturnsfromtheexecutiveto6‰BRA.S…CMDEXIT2thispointif(1)thespecified‚memory'*¦area‚is‚completelyoutsideanymemory'*¦segmentthatbelongsto‚the‚specified'*¦task‚or‚(2)thespecifiedmemoryarea!*¦isinamemory-mappedI/Oarea. 9BADBUFADEQU†LOG040’Controlalsocomestothispointfrom(*¦several‚otherplaces,includingplaces(*¦outsidesubroutineLOGPHY.‚Weusethis$*¦code‚to‚report‚any‚kind‚ofbuffer-#*¦addresserrorthatwecandetect. #*¨Wequeuean‚event‚to‚the‚attached(*¦task‚toindicatethatwehavereceived$*¦abad‚logical‚address,‚and‚then‚we'*¦abort‚processing‚forthecommandthat*¦iscurrentlybeingprocessed.-‰PAGEš#######################################FLOG050„MOVEM.L‚(SP)+,D0-D5/D7/A0†Controlreachesthispointwhenwe've*‰RTS›madeasuccessful‚address‚conversion.&*¦We‚restore‚the‚workingregistersand(*¦returncontroltothecallingroutine.O******************************************************************************* ‰PAGEN******************************************************************************N*********************************************************************************ˆCMDEXIT,HALTEXIT--‚COMMONEXITROUTINE*B*ˆTheCMDEXITroutineisacommonexitroutinecalledfromseveral *ˆplaces.*>*ˆControlcomestooneoffourentrypointsbelowtoterminate *ˆprocessing.*3*’(1)HALTEXITisenteredwhenwereceiveanIOHALT1*–commandforadrivethatisnotintheIOQUEUE,/*–orforadrivethatisintheIOQUEUEbutnot*–currentlybeingprocessed.*8*’(2)CMDEXIT1isenteredwhenwe'vefinishedprocessing0*–acommandwithnoerrors.‚WeinserttheISTAOK*–statusvalueintoD1.2*–Statusandconfigurecommandsexitherewhenall *–iswell.*7*’(3)CMDEXIT2callssubroutineQEVENTT.‚QEVENTT‚queues2*–anI/Ocompletioneventfromthecommandservice2*–routine(notunderinterruptcontrol).‚Thestatus*–fortheI/OrequestisinD1.*–Reasonsforexitinghere:**œunrecognizedvalueintheIOFCTorIOOPT*žfields*œdevicenotready)*œMTAadapterexhibitingbizarrebehavior*œconfigurationerror(*œdevicenotreadywhenwestartaread,*žwrite,oranyothercommand)*œfromLOGPHYiftheI/Obufferisoutof*žthecallingtask'sarea**6*’(4)CMDEXIT3restoresthestackpointerfromSAVESP,4*–andclearsD0toindicatethatthecommandservice5*–routinehasoperatedproperly.EnteringatCMDEXIT3-*–allowsustoabortprocessingatanylevel.*–Reasonsforexitinghere:.*œEverythinghasgonefinesofar,andwehave&*œputtheI/OrequestintotheIOQUEUE**œtobeprocessedunderinterruptcontrol.***ˆSubroutinescalled:QEVENTT*%*ˆEntry:„A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB3*’A6=phy< sicaladdressofTCBoftheattachedtask*2*’D1.B=IOSSTAstatusvalue‚forentryatCMDEXIT2*™orCMDEXIT3‚orHALTEXIT*"*ˆRegistersusage:†0‚1„2‚3‚4‚5‚6‚7*™D„R‚P/R‚**™AP‚P‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:**ˆExitsto:CMRviaRTS*M*****************************************************************************M***************************************************************************** **k‰rC{<ƒ>‹C“?›A£8«=³B»6ÃJËGÓWÛSãFëYóIûI^A`Z#Z+`3_;aCFK<SR[@>*ˆIfthisisanexitfromnIOHALTcommand,puttheeventtype4*ˆforanIOHALTcompletionintoD2(usedbyQEVENTT)**HALTEXITEQU‡*‰MOVE.B„#XPSHLT,D2‰BRA.S†CMDQ CMDEXIT‚EQU‡*;CMDEXIT1MOVEQBƒISTAOK,D1ŽControlreaches‚this‚point‚in‚the'*¦command‚processor‚whenwe'vefinished)*¦processingacommandwithnoerrorsand$*¦we‚want‚to‚queue‚an‚I/Ocompletion(*¦eventtonotifytheattachedtask‚that)*¦theprocessingforthecommandhasbeen&*¦completedwithnoerrors.ƒThe‚status&*¦value‚that‚we‚pickuphereindicates$*¦thatnoerrorshavebeendetected. **:*ˆIfthisisanormalcompletion,puttheeventtypefora'*ˆnormalcompletionintoD2forQEVENTT**CMDEXIT2EQU‡*‰MOVE.B„#XPSNRM,D2 CMDQ…EQU‡*/‰BSR.S†QEVENTTControlreaches‚this‚point‚in‚th'*¦command‚processor‚whenwe'vefinished%*¦processingacommand‚and‚we‚want‚to)*¦queueanI/Ocompletioneventtonotify'*¦theattachedtaskthat‚the‚processing%*¦for‚the‚command‚has‚beencompleted.$*¦The‚status‚value‚for‚the‚completed'*¦command‚is‚inD1.Bwhencontrolcomes*¦here. #*¨Thisroutinecannot‚be‚used‚for‚a'*¦command‚whose‚processingiscompleted(*¦underinterruptcontrolbecause‚events&*¦must‚be‚queued‚differentlywhenthey'*¦arequeuedfroman‚interrupt‚handler.(*¦This‚routineisusedonlywhenwewant$*¦toqueue‚an‚event‚from‚the‚command'*¦service‚routine,‚whichisnotinvoked*¦underinterruptcontrol.-‰PAGEš#######################################BCMDEXIT3MOVE.LƒSAVESP(A5),SPŠRestore‚thestackpointer,andclear4‰MOVEQ„#0,D0D0toindicatethatthecommandservice(‰RTS›routine‚has‚operated‚properly.‚Then$*¦return‚control‚to‚the‚routine‚that$*¦calledƒsubroutine‚COMMANDS.ƒNotice(*¦thatwecanusethisreturnroutine‚to(*¦abort‚processingfromanylevelwithin(*¦thecommandserviceroutinebecause‚we(*¦restore‚thestackpointertothevalue'*¦ithadwhensubroutine‚COMMANDS‚began*¦executionatitsmainlevel. #*¨Our‚handling‚of‚the‚stackpointer'*¦appearstoeliminate‚re-entrancy,‚but'*¦the‚MTA‚driverisstillre-entrantin'*¦thenecessarycontext‚because‚subrou-%*¦tine‚COMMANDS‚can‚never‚becalleda&*¦secondtimeforthesame‚MTAƒchannel(*¦until‚wereturncontrolfromthefirst'*¦calltotheattachedtask.ƒSubroutine)*¦COMMANDScanbecalledre-entrantlyfor"*¦another‚MTAƒchannelƒbecauseƒeach$*¦channel‚has‚its‚own‚CCB.‚Also,the&*¦MTA‚interrupthandlercan‚be‚invoked%*¦while‚subroutine‚COMMANDS‚is‚inthe*¦middleofitsexecution.N******************************************************************************‰PAGEN******************************************************************************N********************************************************************************ˆQUEUEANEVENT*?*ˆSubroutineQEVENTqueuesaneventmessagetothetaskthatis<*ˆattachedtothechannel.‚TherearetwoentrypointstotheC*ˆsubroutine.‚TheQEVENTTentrypointcanbeusedtoqueueaneventB*ˆfromthecommandprocessortotheattachedtask,andtheQEVENTI>*ˆentrypointcanbeusedtoqueueaneventfromtheinterrupt@*ˆhandlertotheattachedtask.‚Ineithercase,itqueuesanI/O(*ˆcompletioneventtotheattachedtask.***3*ˆ************ACKNOWLEDGEMENT*******< *************;*ˆMostofthiscodelifteddirectlyfromtheSASIdriverby*ˆDavidPheanis.**ˆIndetail:*žEventstructure:* *Žoffsets*œ|-----------|------------|*’0‰|EVNTLENƒ|EVNTCODEƒ|*œ|-----------|------------|*’2‰|XRPSTA=‚|XRPKEY=ƒ|*œ|EVNTTYPE‚|EVNTKEY„|*œ|-----------|------------|*’4‰|XRPUID‚=‚EVNTDCB…|*œ|------|------|*œ|˜|*œ|-----------|------------|*“8ˆ|XRPSTV‚=‚EVNTSTAT„|*œ|˜|*œ|-----------|------------|*„EVNTCMSZ‚=ƒ10%*„sizeofnormalI/Ocompletionevent**œ+------------------------+)*’10ˆ|XRPDST‚=|XRPDTP…|„fieldusedfor"*œ|EVNTDSTƒ|Œ|„unsoliciteddevice"*œ|------------------------|„event**„EVNTUNSZ=XRPLEN=12$*„sizeofordinaryunsolicitedevent**œ+------------------------+*œ|XRPDNO‚=|Œ|„fieldusedfor#*œ|EVNTDNUM‚|Œ|„unsoliciteddevice**œ|------------------------|„eventwithno *ºDCBaddress*ºavailable*„EVNTDNSZ=XRP1LEN=14A*„sizeofunsolicitedI/OdeviceeventthatincludestheEVNTDNUM*„field****œ+------------------------+**„EVNTSVSZ‚=„4ˆ|EVNTSVAD|ƒoptionalfield?*„sizeofoptionalfield‚|------------|ƒatoffset2*„ifEVNTCODE=$81‡|˜|*œ|-----------|------------|***„EVNTMXSZ‚=ƒ18 *„sizeofmaximumpossibleevent**:*ˆ(1)Iffrominterrupthandler,put#TOQEVNTI(24)intoD0*Œelse*’put#TOQEVNTT(23)intoD0.B*ˆ(2)StorethestatuscodefromD1intoIOSSTAfieldoftheIOCB.=*ˆ(3)Movesizeofnormalcompletionevent‚intoD3.(EVNTCMSZ)*ˆ(4)MoveEVNTIO=$01intoD4.?*ˆ(5)Reserveenoughroomonthestackforthelongestpossible*Œeventmessage.‚(useLINK)-*ˆ(6)setupA1asatemporarystackpointer.**œ|‚Availablestack‡|*œ|------------------------|*ŒSP--------->ƒ|‚EventareaŒ|*œ|‰.Ž|*œ|‰.Ž|*œ|‰.Ž|*œ|------------------------|!*ŒA0,A1------->‚|‚OldA0valueŠ|*œ|------------------------|*œ|‚Workingregisters…|*œ|‰.Ž|*œ|‰.Ž|*œ|‰.Ž|*œ|------------------------|*?*ˆ(7)UsingA1asapointer,storebytesfortheeventintothe*Œeventareaonthestack.&*”D1statusbyteforXRPSTV(EVNTSTAT)1*”A3physicaladdressofDCBforXRPUID(EVNTDCB)!*”CCBKEY(A5)forXRPKEY(EVNTKEY)*”D2forXRPSTA‚(EVNTTYPE)+*”CCBSVVC(A5)forEVNTSVADifit'snon-zero*—(adjustsizeofevent)*”D4forEVNTCODE*8*ŒIfeventlengthislongerthanCCBASQL(A5)thenchange *’eventlengthinD3totruncate*”D3forEVNTLEN>*ˆ(8)MoveeventintoD2-D6registersusingMOVEM.L(A1),D2-D6"*ˆ(9)Restorestackpointer(UNLK);*ˆ(10)GetphysicaladdressofTCBofattachedtaskintoA0*’CCBRQSTA(A5)@*ˆ(11)BSR.SEXECREQwhichwillkillthesystemifthesystemis2*’unabletoqueuetheeventforsomeweirdreason.$*ˆ(12)Restoretheworkingregisters***ˆSubroutinescalled:EXECREQ*%*ˆEntry:„A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB**’D1.B=I/Ostatus4*’D2.B=XPSNRM($70)ifthisisanormalcompletion-*™XPSHLT($71)ifthisisaIOHALTcompletion*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™D„*‚P‚P *™AP‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister *’D1-D7,A0-A5savedandrestored**ˆExit:*’A3=physicaladdressofDCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB**’D1.B=I/Ostatus4*’D2.B=XPSNRM($70)ifthisisanormalcompletion-*™XPSHLT($71)ifthisisaIOHALTcompletion*6*ˆExitsto:ƒRTStocallingroutineforgoodcompletion%*”InvokesTOKILLERforbadcompletion*M*****************************************************************************M********************************************************************************¦INTERRUPTROUTINE @QEVENTI‚MOVE.Lƒ#T0QEVNTI,D0‹Thisentrypointisusedtoqueue‚an/‰BRA.S…QEVENTI/O‚completion‚event‚from‚the‚MTA)*¦interrupthandlertotheattachedtask.$*¦There‚is‚one‚executive‚request‚for$*¦queuing‚an‚event‚from‚an‚interrupt)*¦handler,= andthereisanotherexecutive%*¦requestforqueuing‚an‚event‚from‚a"*¦routineƒthatƒis‚not‚an‚interrupt'*¦handler.‚Herewegettherequest‚code'*¦for‚the‚executiverequestthatqueues%*¦aneventfromaninterrupthandler.-‰PAGEš#######################################@QEVENTT‚MOVE.Lƒ#T0QEVNTT,D0‹This‚entrypointisusedtoqueuean#*¦I/O‚completion‚event‚from‚the‚MTA)*¦commandprocessortotheattachedtask.$*¦There‚is‚one‚executive‚request‚for$*¦queuing‚an‚event‚from‚an‚interrupt)*¦handler,andthereisanotherexecutive%*¦request‚for‚queuing‚an‚eventfroma"*¦routine‚that‚is‚notƒanƒinterrupt'*¦handler.ƒHerewegettherequestcode'*¦fortheexecutiverequest‚that‚queues(*¦an‚eventfromaroutinethatisnotan*¦interrupthandler. FQEVENTƒMOVEM.L‚D1-D7/A0-A5,-(SP)†Savetheworkingregistersbypushing'*¦them‚ontothestack.‚Wedon'tuseall&*¦oftheseregisters‚directly,‚but‚the&*¦executive‚routine‚that‚queuesevents*¦usessomeofthem. 9‰MOVE.BƒD1,IOSSTA(A4)ŠStorethestatuscodeinto‚the‚IOCB&*¦where‚it‚can‚beexaminedbythetask#*¦that‚originally‚requestedƒtheƒI/O#*¦transactionwe'vejustcompleted. *¨The‚type‚codeforanormalI/O8‰MOVEQBƒEVNTCMSZ,D3ŠcompletioneventisinD2.B.‚Getthe#*¦length‚(in‚bytes)‚of‚a‚normal‚I/O*¦completioneventintoD3.B. 5‰MOVEQBƒEVNTIO,D4ŽGettheeventcodeforan‚I/O‚event*¦intoD4.B.-‰PAGEš#######################################8‰LINK…A0,#-EVNTMXSZŠReserveenoughroomonthestack‚for5‰MOVE.LƒA0,A1thelargestpossibleeventmessage,and(*¦setupA1asatemporarystack‚pointer'*¦for‚pointing‚intotheeventareathat#*¦we've‚just‚reserved‚on‚theƒstack.)*¦We'lluseA1asaworkingregister,and(*¦we'llpreserveA0.‚Weneedtopreserve(*¦A0‚sowecanrestorethestackpointer%*¦afterwe're‚finished‚with‚the‚event%*¦area.ƒThe‚stack‚isnoworganizedas *¦follows. *²|‚AvailableStack„|*²|---------------------|*¦SP------->|‚EventArea‰|*²|Š.Š|*²|Š.Š|*²|Š.Š|*²|---------------------|*¦A0,A1--->|‚OldA0Value‡|*²|---------------------|*²|‚WorkingRegisters‚|*²|Š.Š|*²|Š.Š|*²|Š.Š|*²|---------------------| *¨We're‚going‚to‚buildƒtheƒevent(*¦message‚intheeventareathatwejust&*¦createdonthestack,‚and‚then‚we'll!*¦copyƒtheƒeventƒmessage‚into‚the'*¦registersforqueuingto‚the‚attached%*¦task.ƒBy‚using‚thestackasanarea$*¦for‚building‚the‚event‚message,‚we&*¦assure‚that‚this‚subroutineisfully%*¦re-entrant.‚This‚subroutine‚must‚be$*¦fully‚re-entrant‚because‚it‚can‚be(*¦executedfromboththecommand‚service$*¦routineandtheinterrupthandler. '*¨Noticethattheapproachwetakehere)*¦willworkproperlyforaneventmessage*¦ofanypossiblelength. &*¨Now‚wemuststartbuildingtheevent(*¦message(fromendtobeginning)in‚the*¦eventareaofthestack.-‰PAGEš#######################################5‰MOVE.BƒD1,-(A1)Storethestatusbyteintothe‚event1‰CLR.B„-(A1)area,‚and‚clearthenextbyte.‚There'*¦aretwobytesfortheevent‚status‚in%*¦the‚event‚message,‚but‚oneofthose'*¦bytesmustalwaysbezero.‚We've‚just(*¦filled‚theEVNTSTATfieldoftheevent *¦message. 6‰MOVE.LƒA3,-(A1)StorethephysicaladdressoftheDCB%*¦into‚the‚EVNTDCB‚field‚oftheevent*¦area. =‰MOVE.BƒCCBKEY(A5),-(A1)‡Copythekeyvaluethatwas‚supplied'*¦by‚the‚attachedtaskintotheEVNTKEY*¦fieldoftheeventarea. 6‰MOVE.BƒD2,-(A1)StorethetypecodeintotheEVNTTYPE*¦fieldoftheeventarea. ;‰MOVE.LƒCCBSVVC(A5),D5‰If‚theattachedtaskhasn'tsupplied4‰BEQ.S„L0060aneventserviceaddressforI/Oevents&*¦from‚this‚channel,‚omittheEVNTSVAD*¦fieldoftheevent. 1‰ADD.B„#EVNTSVSZ,D3‹Otherwise,ƒadjust„D3.B,„which6‰MOVE.LƒD5,-(A1)contains‚the‚eventlength,toaccount8‰MOVEQBƒEVNTIOSA,D4Šfortheaddedlength‚of‚the‚EVNTSVAD)*¦field,andputtheserviceaddressinto'*¦theEVNTSVADfieldofthe‚event‚area.(*¦Also,‚changetheeventc= odeinD4.Bto)*¦indicatethatwehaveanI/Oeventwith*¦aserviceaddressincluded. 3L0060„MOVE.BƒD4,-(A1)Storeƒtheƒeventƒcode‚into‚the#*¦EVNTCODEfieldoftheeventarea. 5‰CMP.B„CCBASQL(A5),D3‰If‚the‚event‚message‚we'veƒjust4‰BLS.S„L0070constructedintheeventareaislarger:‰MOVE.BƒCCBASQL(A5),D3‡thanthe‚largest‚event‚the‚attached)*¦taskispreparedtoreceive,changethe&*¦eventlengthinD3.B‚to‚truncate‚the%*¦event‚message‚to‚the‚maximumlength#*¦that‚the‚task‚can‚accommodate.ƒIn&*¦actual‚practice‚we'll‚nevertruncate&*¦anyeventshere‚because‚the‚attached&*¦task‚will‚be‚IOS,whichissetupto(*¦receivethelongesteventmessage‚that*¦wecouldeversend. 5L0070„MOVE.BƒD3,-(A1)Storeƒthe‚event‚length‚into‚the$*¦EVNTLENfield‚of‚the‚event‚area‚to*¦completetheeventmessage.-‰PAGEš#######################################9‰MOVEM.L‚(A1),D2-D6Nowgettheeventfromtheeventarea'*¦into‚theregisters.‚Wepickupenough)*¦registervaluesheretoaccommodatethe'*¦longest‚possible‚eventbecausethat's'*¦easierthanitwouldbetotry‚to‚get)*¦therightnumberofregistervaluesfor#*¦the‚event‚that‚we‚happen‚to‚have.$*¦We're‚safe‚in‚accessing‚beyond‚the(*¦actualeventareainthestack‚because(*¦we‚knowthereismemorywherewesaved*¦theworkingregisters. .‰UNLK…A0•Restorethestackpointersincewe're)*¦nowfinishedwiththeeventareaofthe*¦stack. ;‰MOVE.LƒCCBRQSTA(A5),A0ˆGetthephysicaladdressof‚the‚TCB0‰BSR.S†EXECREQŽfor‚the‚attached‚task‚into‚A0,an$*¦perform‚the‚executive‚requestƒthat#*¦queuesƒthe‚event‚message‚from‚the(*¦registerstotheattachedtask.‚Recall(*¦that‚D0containstheexecutiverequest%*¦codefor‚the‚executive‚request‚that'*¦queues‚the‚eventmessageproperlyfor%*¦the‚current‚environment.ƒSubroutine'*¦EXECREQ‚kills‚theoperatingsystemif)*¦thesystemisunabletoqueuetheevent*¦forsomeunexpectedreason. =‰MOVEM.L‚(SP)+,D1-D7/A0-A5†Restore‚the‚working‚registers,and+‰RTS›returncontroltothecallingroutine.L**************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆEXECUTIVE-REQUESTSUBROUTINE *ˆKILL_IT*A*ˆThesubroutineEXECREQperformsatrap#0ExecutiveRequestandB*ˆkillsthesystemiftheexecutivedoesnotsuccessfullyrespond.**ˆCalledbyQEVENT.*3*ˆKILL_ITkillsthesystemifsomethingverywrong.:*ˆCalledbyCOMMANDSifthedrivenumbersentbyIOSisout*ˆofrange.**ˆSubroutinescalled:**ˆEntry:*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„**™A**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:*<*ˆExitsto:RTStocallingroutineifexecutivesuccessfully"*’performstherequestedfunction.*’#T0KILLERotherwise*M*****************************************************************************M****************************************************************************** EXECREQ‚EQU‡*‰TRAP†#EXEC"‰RTS›ControlreturnsfromtheEXEC*¦tothispointifthecallwas*¦successful.‚Returntothe*¦callingroutine.* KILL_IT‚EQU‡*:‰MOVE.L„#T0KILLER,D0ˆControlreturnshereiftheexecutive/‰TRAP†#EXECwasunabletoperformsuccessfully.(*¦Ifthiseverhappens,killthesystem.#*¦Somethingiswrong,andwecannot*¦continue.M***************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆINTERRUPTHANDLER*+*ˆTheinterrupthandlerdoesthefollowing:1*’Whenaninterruptoccursatourinterruptlevel1*’weseeifitisourinterruptbylookingatthe *’STAT2register'slower4bits.>*’Ifnoneofthelower4bitsisset,thenwereturnwithSR.C/*’bitclearedto> indicatethattheinterruptis*’notours.0*’Iftheinterruptisours,thencontrolgoesto*’theMTINTroutine.***ˆSubroutinescalled:*%*ˆEntry:„A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„RŽP*™A„R**™P=parameterregister*™R=returnregister*™*=destroyedregister*<*ˆExit:…A0=physicaladdressoftheMTA'smemory-mappedI/O*—area+*’D0ƒlowerbyte:‚contentsofSTAT2register+*’D0ƒupperbyte:‚contentsofSTAT1register*9*ˆExitsto:(1)CMRviaRTSifthisisnotourinterrupt.$*’(2)MTINTifthisisourinterrupt*M*****************************************************************************M*****************************************************************************REQINTƒEQU‡%00001111INTERUPTEQU‡*5‰MOVE.L„CCBCHB(A5),A0‡PointA0totheMVME435memory-E*%%%%%%%%%%‚bwnƒ5/17/84‚%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*E*ˆItmaybeimportanttocatchbothSTAT1andSTAT2asclosetogetherD*ˆaspossible,sothatnointerruptsarelost.‚Wedon'twanttosave?*ˆanythingonthestackhere,sowewillusetheregisterD0to*ˆholdbothSTAT1andSTAT2.*'‰MOVE.B„STAT2(A0),D0ˆSaveSTAT2inD0.B&‰SWAP†D0’PutSTAT2inupperwordofD0'‰MOVE.B„STAT1(A0),D0ˆSaveSTAT1inD0.B+‰SWAP†D0’PutSTAT1inupperwordofD0,and*¦STAT2inlowerwordofD0‰MOVE.L„D0,A1SaveD0inA1.2‰AND.B…#REQINT,D0ŠMaskoutallbutlower4bitsof *¦D0(STAT2)./‰IFƒƒTHENŽIfitisnotforus,thenreturn,"ŽRTS–withSR.C=0toindicatethe*¦interruptisn'tours.‰ENDI1‰MOVE.L„A1,D0GetthecontentsofSTAT1andSTAT2*¦backintoD0.*¦FallintotheMTINTroutine.I*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%9***†MOVEQB„REQINT,D0ŠmappedI/Oarea,andchecktheSTAT25***†AND.B…STAT2(A0),D0ˆregistertoseeifthereisan"***†BNE.S‡MTINTinterruptpending.'***†RTS›Ifthereisn'tanMTAinterrupt"*¦pending,returnwithSR.C=0to$*¦indicatetheinterruptisn't‚ours.#*¦TheANDinstructionautomatically*¦clearstheSR.Cbitforus.L****************************************************************************‰PAGEN******************************************************************************N*******************************************************************************"*ˆMTAINTERRUPTCO-ROUTINELINKAGE*)*ˆControlreachesthispointintwoways:*4*’(1)Wehavereceivedaninterruptfromthe‚system,*–whichmeansthat***œ(a)‚someI/Oprocessthatwestartedhas0*–causedaninterrupt.Inthiscasethe‚INTSWTCH0*–variablecontainsanaddressinside‚oneofour**–routines‚such‚as‚read‚or‚write‚or‚rewind**œor*%*œ(b)some‚outside‚force‚has‚pushedƒa0*–buttonon‚thetransportcausingaloadpointor.*–endof‚tapeinterrupt.‚Inthiscase,‚D0>0.*3*’(2)WehavecalledMTINTasasubroutinebecause:*&*Anewentryhasjustbeenaddedtoa*–previously0*–empty‚queueandwewanttostartprocessingit+*–by‚enteringƒPROCQUE.„Inthiscasewehave0*–already‚putthePROCQUEaddressintoINTSWTCH, *–andD0=0.**"*ˆThisroutinedoesthefollowing:**/*’(1)Save‚the‚registers‚we‚will‚need‚touseno*–matterwherewejump.3*–A5,A1,A0,andD0havealreadybeensavedbyCMR*7*’(2)Gettheaddressofthedrive'svariableblockout"*–oftheIOQUEUE,andputintoA1.*9*’(3)IfD0=0,whichmeansthatthisroutinewascalled2*–calledfromCOMMANDS,‚thenenableinterruptsand"*–jumptotheaddressinINTSWTCH.*6*’(4)GetthecontentsofSTAT1intoD1.‚Onentry,the3*–D0registercontainsSTAT1initsupperword,and*–STAT2initslowerword.*2*’(5)DeterminefromSTAT1andSTAT2whichtypeof*–interrupt(s)wehave.+*œif(ST4)parityerror,saveitinSAVEERR*œifST1* ifloadpoint,#*¦ifREWFLAGisset,getaddressin*¦INTSWTCH,‚and *¦jumptoit. * ifEOT,*¦settheSAVEEOTflag, *¦stoptheformatter,andreturn* else‚itis"*¦CCG/ID,set> TAPEDENSto1600bpi*¦00=1600bpi*œifST2 * iffnbsy#*¦gettheaddresssavedinINTSWTCH*¦enableinterrupts,*¨andjumptoit * ifdnbsy*¦donothing* elseitsfilemark*¦saveitinSAVEFM*œif‚ST3!* thisisthehalffullinterrupt.!* jumptotheaddressinINTSWTCH%*setSR.Cbittoindicatethatwe've"*takencareoftheinterrupt,and*RTS*****ˆSubroutinescalled:*8*ˆEntry:„A0=physicaladdressofmemory-mappedMTAarea*’A5=physicaladdressofCCB+*’D0=(a)ifwegotherebyasystemcall,"*›thenD0containsthecontentsof&*›STAT2registerinthelowerwordand+*›thecontentsoftheSTAT1registerinthe *›upperword.1*—(b)ifwegotherebecauseanewentryhasbeen(*›addedtoapreviouslyemptyI/Oqueue,*›thenD0=0.*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„P‚*‚*…* *™A„P‚R…*‚*‚P**™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister*.*ˆExit:…A1=addressofdrive'svariableblock6*’D0.B=(1)STAT2ifwegothereviaasystemcommand(*™(2)0ifwegotherebecauseMTINTwas*calledfromCOMMANDS.**ˆExitsto:9*’(1)IftheinterruptwascalledfromCOMMANDS,exitsto *–PROCQUE.*;*’(2)IftheinterruptwasafnbsyoraBOTwhenrewinding,*–orahalffullinterrupt,-*–exitstoaco-routinesegment.‚Controlwill/*–eventuallyreturnfromtheco-routinesegment(*–through‚theINTRTNroutine,ƒwhichwill*–returnustoCMR.*4*’(2)IftheinterruptwasneitherafnbsynoraBOT3*–forrewind,norhalffull,exitistoCMRviaRTS.*M*****************************************************************************M***************************************************************************** MTINT„EQU‡*4*%%%%%%%%%%%%%%%ƒBWN5/17/84‚%%%%%%%%%%%%%%%%%%%%%%%*?*ˆInterruptsareinhibitedatourinterruptlevelwhenweenter*ˆthisroutine.#*ˆWearegoingtokeepthemmasked.*2*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%**2*ˆIfnocommandis‚intheIOQUEUE,thenthisisan$*ˆinterruptthatshouldjustreturn.**‰TST.W…IOQCNT(A5) ‰BEQ.L…MTINT2**=*ˆIfcontrolcomesherethenwehaveanentryintheIOQUEUE.=*ˆSavealltheregisterswewillusenomatterwherewejump.4*ˆA5,A1,A0,andD0havealreadybeensavedbyCMR.***-*ˆTheregistersthatwesaveareD1-D7/A3-A4.1*ˆThesearethesameoneswerestoreuponreturn.*RTSREGS‚REG†D1-D7/A3/A4‰MOVEM.LƒRTSREGS,-(SP)"*ˆSetA3<---addressinINTSWTCH.*”INTSWTCHcontainsoneof:0*—(1)addressofPROCQUEifweareprocessingan%*›entryinapreviouslyemptyIOQUEUE)*—(2)addressputintoINTSWTCHbyINTRTN*‰MOVE.L„INTSWTCH(A5),A3**)*ˆSetA1<---loc(drive'svariableblock)* ‰MOVE.L„IOQUEUE(A5),A1 **<*ˆIfD0=0,thenthisroutinehasbeencalledfromCOMMANDS-*ˆandwejustjumptotheaddressinINTSWTCH** ‰TST.B…D0 ‰IFˆTHEN “JMP‚(A3)‰ENDI**A*ˆOtherwise,checkbits0,1,2,3ofSTAT2andbitsofSTAT1tosee/*ˆRecallthatSTAT1isintheupperwordofD0.!*ˆwhattypeofinterruptwehave.* ‰MOVE.L„D0,D1‰SWAP†D1*%%%%%%%%%ƒBWN9/18/84*=*‚Theremaybeaninterruptpending,sodon'treadSTAT1yet.****†MOVE.B„STAT1(A0),D1 *%%%%%%%%%%%%***ˆCheckforparityerror**‰BTST†#ERRORB,D0 ‰IFƒƒTHEN:*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ˆbwn‡4/4/847ŽTAS.B…SAVEERR(A1)„Storethefactthatwegotanerror.5ŽIF…„THEN†Oops!Wegotaseconderrorinterrupt.'*¦Let'sstopthetapeasweusedtodo.*=*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%“BSR.L…STOPTAPE“JMP‡(A3)JumptocontinuationENDI*°ofserviceroutine.:*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ˆbwn‚4/4/84"‰ENDIŠtomatchupwithinsertedIF@*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*I*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>? >>>>>>>>>>>>>>>**<*ˆCheckforbeginningoftape,endoftape,ordensityburst**‰BTST†#BOTEOTDB,D0 ‰IFƒƒTHEN”BTST†#LDPNTB,D1„Loadpoint?**(*ˆIfthiswasaloadpointinterrupt,and=*ˆifwehavepreviouslyissuedarewindcommand,thenjumpto*ˆtheaddressinINTSWTCH** •IFƒƒTHEN›TST.B„REWFLAG(A1) ›IF‚ƒTHEN¢SF.B†REWFLAG(A1)ƒClearREWFLAG ¢JMP‡(A3)œENDI**?*ˆIftheBOTEOTDBbitoftheSTAT2registerwasset,andweareE*ˆnotatbeginningoftapeoratendoftape,thenthiswasadensity<*ˆburst,andthetapewearereadingisrecordedin1600bpi**•ELSEBTST…#EOTB,D1‹Endoftape? IFƒƒTHEN**6*ˆIt'snotendoftape,soitmustbeadensityburst.(*ˆPutthePEdensitycodeintoTAPEDENS.**¥MOVE.Bƒ#XDSD1600,TAPEDENS(A1)>*<<<<<<<<<<<<<<<<<<<< INSERTED 12/5/83 >>>>>>>>>>>>>>>>>>>>>>>žELSE*1*ˆItisendoftape.Settheflag.‚Don'tstopthe*ˆformatter.***£MOVE.B„#FORDISCD,DSCMD(A0)¥ST.B†SAVEEOT(A1)@*<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>žENDI•ENDI‰ENDI**0*ˆCheckforformatternotbusy/filemarkdetect7*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ˆbwn‚4/4/84*ˆCheckfordatanotbusy* *ˆbwn‚9/18/84=*ˆAFNBSYinterruptmayhavecomeinbetweenthetimeweread>*ˆSTAT2andthetimewereadSTAT1,soreadtheSTAT1register1*ˆtodeterminewhetherwehaveaFNBSYcondition..*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%**%‰BTST†#FNBSYB,D1„Formatternotbusy?‰IFƒƒTHENˆIfso,jump. ŽJMP‡(A3)‰ENDI*<*‚Formatterisbusy,socheckfordatanotbusyandfilemark*7*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%‰BTST†#FMFNBSYB,D0 ‰IFƒƒTHEN'**ŒBTST†#FNBSYB,D1„Formatternotbusy?**ŒIFƒƒTHENˆIfso,jump.**‘JMP‡(A3)**ŒENDI@*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*ˆbwn‚4/4/84%ŽBTST†#DNBSYB,D0†Isitdatanotbusy?'ŽIF…ƒTHEN‡Ifnot,mustbefilemark.•ST.B†SAVEFM(A1)ŽENDI=*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%‰ENDI**&*ˆCheckforFIFO‚<=halfempty(write)*˜>=halffull(read)7*ˆNotethatwecheckforthisafterformatternotbusy.9*ˆIndirectmoderead,ifwegetbothinterruptsatonce,9*ˆwewillreturnviaformatternotbusy,andwillnotset*ˆthehalffullflag.**‰BTST†#FIHAFIB,D0 ‰IFˆƒTHEN“ST.B†HALFFULL(A1) “JMP‡(A3)‰ENDI*MTINT3*=*ˆRestoretheregistersthatwesavedatthebeginningofthe *ˆroutine.**‰MOVEM.Lƒ(SP)+,RTSREGS**>*ˆSetthecarrybitofthestatusregistertoindicatethatwe*ˆhaveprocessedtheinterrupt.**MTINT2*D*ˆWearegoingtoreturncontroltotherestoftheoperatingsystem*2‰MOVE.B„#1,D0…Theseinstructionssetthecarrybit%‰SUBQ.B„#2,D0…fasterthanOR.B‚#1,CCR‰RTSJ************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆPROCESSNEXTQUEUEENTRY*@*ˆControlcomestothisco-routinesegmentwhenwewanttostart?*ˆprocessingthefrontentryoftheIOQUEUE.‚Controlcomeshere*ˆundertwocircumstances:*6*’(1)AnentrywasjustplacedinanemptyIOQUEUEand,*–MTINTwascalledfromsubroutineCOMMANDS.*4*’(2)AnI/Oeventwasjustcompletedandthisentry/*–hasjustmovedintothefrontoftheIOQUEUE.*'*ˆInterruptsaredisabledatourlevel.*=*ˆRecallthatthisdrivercancontroluptoeighttransports.C*ˆButitprocessesI/Orequestsfromthesetransportssequentially.%*ˆThisisthereasonfortheIOQUEUE.*!*ˆTheroutinedoesthefollowing:**’ResettheMTAadapterboard.-*’EnableinterruptsontheMTAadapterboard.*2*’Selectthetransportcorrespondingtothenumber6*’intheDRIVENUMfieldofthed? rive'svariableblock,**’usingTAPEDENSasthetransportdensity.**/*’ClearouttheFIFO.(bufferonadapterboard)**5*’ExaminetheMOTIONfieldofthedrive'sI/Opacket.2*’IfMOTION=FORWARDandEOT,putISTAEOVintoD1*œandgotoMTADONE2*’IfMOTION=REVERSEandBOT,putISTABOVintoD1*œandgotoMTADONE)*’Findaddressinoptableandjumptoit.** ADDRESS…MTACMD*–-------ƒ--------„------- *–forward *–commands*™0†DORDFWD…RDFWDCMD($00)*™1†DOWRITE…WRITECMD($02)*™2†DOSFMFWD„SFMFWCMD($10)*™3†DOSPFWD…SPFWDCMD($14)*™4†DOERASE…ERASECMD($16)*™5†DOWRTFM…WRTFMCMD($06)* *–reverse *–commands*™6†DOSFMREV„SFMREVCD($11)*™7†DOSPREV…SPREVCMD($15)*™8†DOREWIND„REWINDCD($01)**–don'tcare%*™9†DOCONFG…usesREWINDCDandRDFWDCD**ˆSubroutinescalled:‚SELECT*<*ˆEntry:„A0=physicaladdressofmemory-mappedMTAI/Oarea.*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™D„*‚R‚R‚R‚* *™A„P‚P…*‚R‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister*%*ˆExit:…A4=physicaladdressofIOCB *’D1=errormessageforMTADONE!*’D3=contentsofTRSELregister**ˆExitsto:*’oneof‡MTADONE *ŸDORDFWD *ŸDOWRITE *ŸDOWRTFM *ŸDOSFMFWD *ŸDOSFMREV *ŸDOSPFWD *ŸDOSPREV *ŸDOERASE *ŸDOREWIND *ŸDOCONFG*M*****************************************************************************M********************************************************************************C*ˆOPTABLE--TheOPTABLEcontainsoffsets‚tothecodethatperforms9*“theworkrequiredbyacommandexecutedunderinterrupt *“control.=*“Notethattheorderoftheoffestsisthesameastheorder7*“ofthecorrespondingcommandsintheCMDSWITtablein8*“theCOMMANDSroutine,wheretheIOFUNCTindexingvalue*“iscalculated.** OPTABLE‚EQU‡*‰DC.W†DORDFWD-OPTABLE‰DC.W†DOWRITE-OPTABLE‰DC.W†DOSFMFWD-OPTABLE‰DC.W†DOSPFWD-OPTABLE‰DC.W†DOERASE-OPTABLE‰DC.W†DOWRTFM-OPTABLE‰DC.W†DOSFMREV-OPTABLE‰DC.W†DOSPREV-OPTABLE‰DC.W†DOREWIND-OPTABLE‰DC.W†DOCONFG-OPTABLE‰DC.W†0+WRITE„EQU‡1“Identifierforwritecommandin*¦interruptserviceroutine. PROCQUE‚EQU‡*******ˆGetthephysicaladdressofIOCBintoA4**‰MOVE.L„IOCBPTR(A1),A4***ˆResettheformatter.**‰MOVE.B„#FORDISCD,DSCMD(A0)***ˆResettheMTAadapterboard.!*ˆEnableinterruptsattheboard.D*ˆResettingtheboardputsusinbufferedmodeforreadsandwrites,,*ˆandalsoselectsformatter0,transport0.+*ˆItalsodisablesinterruptsattheboard.**‰MOVE.B„#MTARSTCD,DSCMD(A0) ‰ENABLMTA*A*ˆTheselectsubroutinefillsinbits0,1,2oftheD3registertoD*ˆproperlyselectthetransportdefinedbytheDRIVENUMfieldofthe*ˆdrive'svariableblock.**8*ˆSELECTalsofillsin‚theTRSELDBbitofD3asfollows:7*’Iftapedensity(inD0)is1600bpiorifthetapeis-*•blank,thenclearTRSELDB.‚Thiswillselect$*•1600bpiasthetransportdensity./*’Iftapedensityis800bpi,select800bpias3*•thetransportdensitybysettingtheTRSELDBbit.*-*ˆNote:thevalueinTAPEDENSisinitially0.2*ŽAlso,a"blank"tapecanhavesomethingonitso8*ŽthatitstopsbeforeEOT.‚Inthatcase,wewillassume*Žitis800bpi.*;*ˆSELECTthenselectsthetransportbywritingtotheTRSEL*ˆregister.***/*%%%%%%%%%%% BWN 5/4/84 %%%%%%%%%%%%%%%%%%%%%%%‰MOVE.B„TAPEDENS(A1),D0$*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ‰BSR.S‡SELECT*&‰BSR.L…CKRDYCheckreadybeforewetry#*¦anythingelse.‚Zbitofcondition#*¦codeofstatusregisterissetif*¦notready.*‰BEQ.L…MTADONE**:*ˆExaminethemotionfieldofthedrive'svariablepacket.3*ˆIfthecommandrequiresreversemotionandweare:*ˆatthebeginningoftape,thenputanerrormessageinto*ˆD1andgotoMTADONE**%%%%%%%%%%%%ƒbwn**ˆCommen@ tedout9/20/84***‡BTST†#EOTB,STAT1(A0)**‡IFƒƒAND.B **Œ#FORWARD‚‚MOTION(A1)ƒTHEN**‘MOVE.B„#ISTAEOV,D1**‘BRA.L…MTADONE**‡ENDI0*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%‰BTST†#LDPNTB,STAT1(A0)‰IFƒƒAND.BŽ#REVERSEƒ‚MOTION(A1)ƒTHEN“MOVE.B„#ISTABOV,D1“BRA.L…MTADONE‰ENDI***ˆClearouttheFIFOD*ˆThisisnotnecessaryforallcommands,butitisnecessarybefore9*ˆwedoanyreadsorwritesandafterwritingafilemark,E*ˆsowemayaswellputithereandstartoutwithacleanslateeach*ˆtime.*‰BTST†#FIEMPB,STAT2(A0)‰WHILE…†DO“MOVE.B„DATAIO0(A0),D0“BTST†#FIEMPB,STAT2(A0)‰ENDW**3*ˆUsingIOFUNCT,indexintotheOPTABLEandjumpto:*ˆtheaddressoftheroutinethatshouldbeexecutednext.*?*ˆNotethatIOFUNCTmustbemultipliedbytwotoindexintothe*ˆtableofwordoffsets.***‰LEA‡OPTABLE(PC),A3†A3<---OPTABLaddress ‰MOVE.W„#0,D4‰MOVE.B„IOFUNCT(A1),D4)‰ADD.W…D4,D4AddD4toD4(multiplyby2)*¦D4<---indexintoOPTABL5‰MOVE.W„0(A3,D4),D4‰D4<---contentsofthisentryin*¯OPTABL‰JMP‡0(A3,D4.W) L**************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆSELECTTRANSPORT*A*ˆThisroutineiscalledfrom‚PROCQUEandDOWRITEtofillinbits<*ˆ2,1,0ofD3withthepropervaluestoselectthe‚transport:*ˆcorrespondingtothenumberinthe‚DRIVENUM‚fieldofthe=*ˆdrive'svariableblock,andtofillinbit3ofD3withthe?*ˆpropervaluetoselectthetransportdensityaccordingtothe*ˆfollowingrule::*ˆ(1)iftherequesteddensityis800bpi,select800bpi. *ˆ(2)otherwiseselect1600bpi.*?*ˆAtthispointwearenotconcernedwithwhetherornotwecan(*ˆactuallychangethetransportdensity.***ˆTRSELregister:**Œ7ƒ6ƒ5ƒ4ƒ3ƒ2ƒ1ƒ0#*Š---------------------------------*Š|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|#*Š---------------------------------*Œ^ƒ^ƒ^ƒ^ƒ^ƒ^ƒ^ƒ^*Œ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|%*Œ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ+----0=Formatter0*Œ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|‰1=Formatter1*Œ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ| *Œ|ƒ|ƒ|ƒ|ƒ|ƒ|ƒ|‰00=Transport0**Œ|ƒ|ƒ|ƒ|ƒ|ƒ+---+--------10=Transport1*Œ|ƒ|ƒ|ƒ|ƒ|‘01=Transport2*Œ|ƒ|ƒ|ƒ|ƒ|‘11=Transport3*Œ|ƒ|ƒ|ƒ|ƒ|2*Œ|ƒ|ƒ|ƒ|ƒ+----------------1=PEmode(1600bpi)!*Œ|ƒ|ƒ|ƒ|•0=NRZImode(800bpi) *Œ|ƒ|ƒ|ƒ|.*Œ+---+---+---+--------------------don'tcare****ˆDRIVENUMŒFormatter/transport*ˆ--------Œ-------------------*Œ0“0ˆ0*Œ1“0ˆ1*Œ2“0ˆ2*Œ3“0ˆ3*Œ4“1ˆ0*Œ5“1ˆ1*Œ6“1ˆ2*Œ7“1ˆ3**ˆSubroutinescalled:**ˆEntry:5*’A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB%*’D0.B=densityfortransportselect*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™D„P‚R‚*‚R‚P*™A„P‚P**™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister*)*ˆExit:…D3.B=contentsofTRSELregister**ˆExitsto:RTSto‚PROCQUE*M*****************************************************************************M******************************************************************************* *ˆMVME435TransportSelectTable*#*ˆDevicenumber‘Bits2,1,0ofTRSEL#*ˆ-------------‘------------------- *0›0‚0‚0 *1›1‚0‚0 *2›0‚1‚0 *3›1‚1‚0 *4›0‚0‚1 *5›1‚0‚1 *6›0‚1‚1 *7›1‚1‚1**TRTABLE‰DC.B†00‰DC.B†04‰DC.B†02‰DC.B†06‰DC.B†01‰DC.B†05‰DC.B†03‰DC.B†07SELECTƒEQU‡****ˆSaveregisters**‰MOVEM.LƒD0/D2,-(SP)**:*ˆGetthedrivenumberintoD2anduseittoindexintothe:*ˆtransporttable.Putthenumberfromthetransporttable *ˆintoD3.6*ˆThevalidityofthedrivenumberhasbeencheckedin*ˆCOMMANDS.** ‰MOVE.W„#0,D2‰MOVE.B„DRIVENUM(A1),D2‰MOVE.B„TRTABLE(PC,D2.W),D3**:*ˆSetorclearthebitoftheTRSELregistertha@ tcontrols8*ˆthetransportdensity.‚Settingthebitselects800bpi(*ˆandclearingthebitselects1600bpi./*ˆIfthetapeisblankwewillselect1600bpi.** ‰IF.B‚D0‚ƒ#XDSD800ƒTHEN“BCLR†#TRSELDB,D3‰ELSE“BSET†#TRSELDB,D3‰ENDI**‰MOVE.B„D3,TRSEL(A0)ˆSelectthetransport.%*¦Densityselectionisnotdetectable&*¦untilareadorwritehasbeendone.*8‰MOVE.B„D3,SAVESEL(A1)†Savetheselectionforlateruse.**ˆRestoreregisters**‰MOVEM.Lƒ(SP)+,D0/D2‰RTSN****************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆDOTHEWRITECOMMAND*A*ˆControlcomestothiscommandfromPROCQUEwhenwehaveawrite%*ˆcommandtosendtotheMTAadapter.A*ˆAtthispoint,thetransporthasalreadybeenselectedwiththe*ˆdensityinTAPEDENS.*8*ˆWeareguaranteedthatthetapeisnotatendoftape.*=*ˆItispossibleforthetransporttoberewoundtoloadpoint<*ˆwhileweareinthisroutine.‚Ifthathappens,resultsare*ˆunpredictable.*"*ˆThisroutinedoesthefollowing:*4*’(1)CheckWRTPRTinthedrive'svariableblockand/*–ifwriteprotected,putISTAWPmessageinD1,*–gotoMTADONE.**’(2)Ifatloadpoint2*™settheflagtoremindustoupdatetapedensity*™Ifwecanchangedensityand4*™ifadensityisrequested,re-selectthetransport*œwiththatdensity**=*’(3)PutthevalueintheIOSERTintoNUMERASE,thevariable&*–whichtellsushowmanytimeswecan1*–erasewhiletryingtowritetothetapewithno *–errors.*9*’(4)PutthevalueinIOSWRTintoƒNUMWRITE,thevariable-*–whichtellsushowmanytimeswecantryto,*–writeonasectionoftapebeforeerasing.*3*–TheconfigureandmountcommandsetsupIOSWRTso*–thatitsvalueisnon-zero.*4*’(5)Checksizeofdatabuffer,andifgreaterthan*–4K,usedirectmode: *œ(1)write2KbytestotheFIFO.*œ(2)returnto‚CMRto"wait"foraninterrupt-*œ(3)sendthewritecommandtotheformatter**œ(4)whilethereareatleast2Kbytesto'* transfer,write2KbytestotheFIFO.+*œ(5)writethelastbytestotheFIFO,and$* writeintothelastwordregister.#*–If4Korless,usebufferedmode:!*œ(1)writethebytestotheFIFO&*œ(2)writeintothelastwordregister.*œ(3)sendthewritecommandtotheformatter..*–Whenthedirectmodecommandisimplemented,*–thiswillchange.*"*’(6)ChecktheSAVE___variables.*œifSAVEEOT*ŸputISTAEOVintoD1*œifSAVEERR*Ÿsubtract1fromNUMWRITE*ŸifNUMWRITE‚>0*¢dospacereversecommand*¢BSR.SINTRTN*¢gobackto(4)*Ÿelse*¢subtract1fromNUMERASE*¢ifNUMERASE>0*¦dothespacereversecommand*¦BSR.SINTRTN*¦dotheerasecommand*¦BSR.SINTRTN*¦ifSAVEEOT*©putISTAEOVmessageinD1,*¦otherwise,goto(3)*¢else*¥putISTACRCintoD10*’(7)TAPEDENS<---TRANDENS‚ifthiswasawrite*—fromloadpoint.*’(8)GotoMTADONE*5*ˆSubroutinescalled:INTRTN,WRITDATA,SELECT,WRITE2K**<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oares/*’A1=pointertodrive'svariableblockinCCB*’A4=physicaladdressofIOCB*’A5=physicaladdressofCCB#*’D3.B=contentsofTRSELregister*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚R‚*…**™A„P‚PˆP‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister*;*ˆExit:…A0=physicaladdressofMTAmemory-mappedI/Oares/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*’D1.B=statusmessage**ˆExitsto:MTADONE*M***************************************************************************** DOWRITE‚EQU‡** **ˆCheckforwriteprotection**‰MOVE.B„#ISTAWP,D1‰BTST†#WRTPRTB,STAT1(A0)‰SNE‡WRTPRT(A1)‰BNE.L…MTADONE*****ˆCheckforloadpoint.**‰BTST†#LDPNTB,STAT1(A0)1‰SNE‡LDPNTFLG(A A1)ˆSetflagifwe'reatloadpoint,*¦clearitotherwise.****ˆIfatloadpoint, *ˆcallSELECT‚to‚changedensity.** ‰IFˆ…THEN.ŽTST.BƒREQDENS(A1)‹Ifuserrequestsadensity, ŽIF†‡THEN 4–MOVE.B‚CONFGBLK+IOSDEN(A1),D0…Selectuserrequested *µdensityŽELSE)–MOVE.Bƒ#XDSD1600,D0†elseselect1600bpiŽENDI ŽBSR.S…SELECT‰ENDI*%*ˆCopythebufferlengthintoanother9*ˆvariablesothatwedon'twipeouttheoriginalincase)*ˆweneedtotrythewriteasecondtime.** ‰MOVE.L„IOBUFLEN(A1),SAVELEN(A1)***5*ˆAlliswellsofar.‚Startthewriteloopbyputting/*ˆtheretryvaluesforwritinganderasinginto*ˆNUMWRITEandNUMERASE.*** *%%%%%%%%%%%%%…debug…bwn5/23/84*ˆGetacleanslatefortrace*‰CLR_TR„WTR*%%%%%%%%%%%%%%%%%%%%%%%%%%%(‰MOVE.B„CONFGBLK+IOSERT(A1),NUMERASE(A1) WRLOOP1‚EQU‡*(‰MOVE.B„CONFGBLK+IOSWRT(A1),NUMWRITE(A1) WRLOOP2‚EQU‡**&‰SF.B†SAVEERR(A1)‰Cleartheerrorflag,‰SF.B†SAVEEOT(A1)‰Cleartheendoftapeflag**3*ˆGet‚theoriginal‚bufferpointerandbufferlength**!‰MOVE.L„IOBUFLOC(A1),IOBUFPTR(A1) ‰MOVE.L„SAVELEN(A1),IOBUFLEN(A1)*****ˆCheckforbufferlargerthan4K(MAXBUF)**&‰IF.L†IOBUFLEN(A1)ˆ†#MAXBUFƒTHEN.L>*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*;*ˆIfdirectmodewritehasproblems,wemaywanttoprevent*ˆtheuserfromdoingit.:*ˆHereweleaveroomforsomecodetorejectdirectwrite.***‘MOVE.B„#ISTABO,D1**‘BRA.S†MTADONE“NOP“NOP“NOP“NOP**D*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< '“MOVE.B„D0,DIRSL(A0)ˆSelectdirectmode*%“BSR.L…WRITE2KWrite2KbytestoFIFO"“BSR.L…INTRTNŽ"Wait"forinterrupt*%%%%%%%%%‰BWNDEBUG5/23/84 ‰TRACEW1,WTR*°totellusFIFOhalffull“SUBI.L„#HAFBUF,IOBUFLEN(A1)“BSR.L‡CKRDY“BEQ.L‡MTADONE“MOVE.B„#WRITECMD,GRCMD(A0)*%%%%%%%%%% ‰TRACEW2,WTR**<*ˆControlreturnsherewhenahalffullorformatternotbusy*ˆinterruptisreceived.;*ˆWhilethebufferlengthisatleast2K,write2Kbytesto*ˆtheFIFO.**WRLOOP3 ”BSR.L…INTRTN*%%%%%%%%%%%%%%% ‰TRACEW3,WTR*6*ˆWhenwereturnhere,D0.BhasthecontentsofSTAT2.*:*ˆIfbufferlengthislessthanorequalto2Kbytes,thenD*ˆcallwritedatatowritethelastofthebytesandwritelastword.**#*%%%%%%%%%%%%%%%%%%%%%%‡BWN†5/23/84“REPEAT&–BTST„#FIHAFB,D0‰CheckFIFOhalfempty(–IFƒƒTHEN‹Ifso,write2KmorebytesžBSR.L„WRITE2KžSUBI.Lƒ#HAFBUF,IOBUFLEN(A1)–ENDI –BSR.LƒINTRTNWaitforinterrupt *%%%%%%%%%%%% ‰TRACEW4,WTR"“UNTIL.LƒIOBUFLEN(A1)ƒƒ#HAFBUF “BSR.L†WRITDATA‰ELSE¤Heretowrite4Korfewer*°bytes(bufferedmode)“BSR.L†WRITDATA“BSR.L†CKRDY“BEQ.L†MTADONE“MOVE.B…#WRITECMD,GRCMD(A0)‰ENDI ‰BSR.L…INTRTN*%%%%%%%%ŠDEBUG ‰TRACEW5,WTR J****************************************************************************ˆTHEWRITECOMPLETED*I**************************************************************************+**‡INHIBMTAŒInhibitinterruptsattheboard'**‡ENABLEnableinterruptsatourlevel*‰CKTRDEN‰MOVE.B„TRANDENS(A1),D2‰TST.B…LDPNTFLG(A1) ‰IFˆ†THEN“MOVE.B„D2,TAPEDENS(A1)“SF.B†LDPNTFLG(A1)‰ENDI*9*ˆTestforparityerror.‚Ifnoparityerrorwasdetected,6*ˆthengocheckforendoftape.Otherwise,spaceback;*ˆtothebeginningoftheblock‚onthetape,andtryagain.**‰TST.B…SAVEERR(A1)‰IF‚‚THEN.LF************************************************************************ˆERRORSONTHEWRITE*F************************************************************************‡BEQ.L…WRFIN2*6*ˆIftherewasanerror,resettheadapterboard,then*ˆre-selectthetransport.%*ˆAndenableinterruptsattheboard.***%%%%%%%%%%%%‚DEBUG‚BWN‚5/23/84 ‰TRACE…ER,WTR*%%%%%%%%%%%%%%%%%%‰MOVE.B„#MTARSTCD,DSCMD(A0)‰MOVE.B„SAVESEL(A1),TRSEL(A0) ‰ENABLMTA**E*ˆCheckreadyagain.‚Thistime,ifwA earen'tready,sowecan'tspace#*ˆreverse,senddataerrormessage.**‰BSR.L…CKRDY ‰IF‚‚THEN*ŒMOVE.B„#ISTACRC,D1“Meansgarbagewritten.ŒBRA.L…MTADONE‰ENDI**1*ˆChecktoseeifthereareanywritetriesleft.**‰SUBQ.B„#1,NUMWRITE(A1) ‰IFƒƒTHENŽMOVE.B„#SPREVCMD,GRCMD(A0) ŽBSR.L…INTRTN&ŽBRA.L†WRLOOP2Œloopbackandre-write.‰ENDI**6*ˆSinceweareoutofwritetries,seeifwecanerase *ˆthetapeandstartoveragain.>*ˆIfweareoutoferasetries,puttheISTACRCmessageinD1,*ˆandgotoMTADONE.**‰MOVE.B„#ISTACRC,D1‰TST.B…NUMERASE(A1)‰BEQ.L…MTADONE**5*ˆSincewearenotoutoferasetries,spacereverse.**‰BSR.L…CKRDY ‰IF‚‚THEN.ŒMOVE.B„#ISTACRC,D1‰Ifwecan'tspacereverse,#ŒBRA.L…MTADONEreturnerrormessage‰ENDI*‰MOVE.B„#SPREVCMD,GRCMD(A0) ‰BSR.L…INTRTN ‰BSR.L…CKRDY‰BEQ.L…MTADONE &‰SF.B†SAVEERR(A1)‰Cleartheerrorflag 8‰MOVE.B„#ERASECMD,GRCMD(A0)thenwritetheerasecommand#‰BSR.LƒINTRTN”totheGRCMDregister**1*ˆIftherewasanerror,wemustresettheboard.**‰TST.B…SAVEERR(A1) ‰IFˆƒTHEN“MOVE.B„#MTARSTCD,DSCMD(A0)“MOVE.B„SAVESEL(A1),TRSEL(A0) “ENABLMTA‰ENDI**,*ˆChecktoseeifwearenowatendoftape.9*ˆIfso,branchtoMTADONEwiththeendoftape(ISTAEOV) *ˆmessage.**‰CKEOT‰TST.B…SAVEEOT(A1)‰BNE.L…MTADONE**D*ˆIfwearenotatendoftape,decrementthenumberoferasetries,*ˆandstarttheloopagain.**‰SUBQ.B„#1,NUMERASE(A1)‰BRA.L†WRLOOP1 **@*ˆControlcomestothispointifwesucceededinwritingwithno*ˆparityerrors.**‰ENDIJ****************************************************************************ˆNOERRORSONTHEWRITE*K******************************************************************************‚WRFIN2ƒEQU‡**?*<<<<<<<<<<<<<<<<<<<< COMMENTED OUT 11/30/83 >>>>>>>>>>>>>>>>>>**A*ˆComparetapeandtransportdensitiesandsendamessageifthey*ˆaredifferent.<*ˆAtthispoint,thetransportdensityhasbeenupdated,and*ˆisinD2.B****‡MOVEQB„ISTADEN,D1**‡CMP.B…TAPEDENS(A1),D2**‡BNE.S‡MTADONE*=*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>***ˆCheckforendoftape.***‰CKEOT;*<<<<<<<<<<<<<<<<<<<INSERT11/30/83ƒ>>>>>>>>>>>>>>>>>>>>>>**>*ˆItmaybethatweranpastendoftape,sochecktheSAVEEOT@*ˆflag.TheendoftapeerrorcodeisstillinD1fromtheCKEOT*ˆmacro.>*ˆIftheusertriestowriteorreadfromthispoint,thetape*ˆwillrunofftheend.*‰TST.B…SAVEEOT(A1)‰BNE.L‡MTADONE*<*<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> *ˆNoerrors!**‰MOVE.B„#ISTAOK,D1‰BRA.L†MTADONEM***************************************************************************** ‰PAGE‰OPT‡PCSN******************************************************************************N******************************************************************************* *ˆWRITE2K*9*ˆThisroutinetransfers2KbytesfrommemorytotheFIFO***ˆSubroutinescalled:*/*ˆEntry:„A0=addressofmemory-mappedI/Oarea(*’A1=addressofdrive'svariableblock*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D* *™A„P‚P…#**™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister**ˆExit:**ˆExitsto:*M*****************************************************************************M******************************************************************************* WRITE2K‚EQU‡**WR2KREGSREG‡A3/D0/D3‰MOVEM.LƒWR2KREGS,-(SP)**‰MOVE.L„IOBUFPTR(A1),A3‰MOVE.L„#HAFBUF,D3‰REPEAT**/*ˆMove4*8or32bytesoneachlooprepetition.7*ˆLoopwillrepeat64times,foratotalof2048bytes.**“MOVE.L„(A3)+,D0“MOVEP.LƒD0,DATAIO0(A0) “MOVE.L„(A3)+,D0“MOVEP.LƒD0,DATAIO0(A0) “MOVE.L„(A3)+,D0“MOVEP.LƒD0,DATAIO0(A0) “MOVE.L„(A3)B +,D0“MOVEP.LƒD0,DATAIO0(A0) “MOVE.L„(A3)+,D0“MOVEP.LƒD0,DATAIO0(A0) “MOVE.L„(A3)+,D0“MOVEP.LƒD0,DATAIO0(A0) “MOVE.L„(A3)+,D0“MOVEP.LƒD0,DATAIO0(A0) “MOVE.L„(A3)+,D0“MOVEP.LƒD0,DATAIO0(A0) “SUBI.L„#32,D3 ‰UNTIL… ‰MOVE.L„A3,IOBUFPTR(A1)‰MOVEM.Lƒ(SP)+,WR2KREGS ‰RTS ‰PAGEN******************************************************************************N********************************************************************************ˆWRITEDATA*9*ˆWRITDATAmovesdatafromtheuserbuffertotheDATAIO0;*ˆregisteroftheMVME435.‚Afterallthedatainthebuffer<*ˆismoved,WRITDATAwritesintotheLASTWRDregisterofthe1*ˆMVME435,therebydelimitingtheendofablock.A*ˆThisroutineusestheMOVEPinstructiontospeeduptransferof*ˆdata.*D*ˆTheFIFOhasbeencleanedupinPROCQUE,sowehaveacleanstart.**ˆSubroutinescalled:*@*ˆEntry:„A0=physicaladdressofMVME435memory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™D„*Ž*‚* *™A„P‚P…***™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister**ˆExit:9*’A0=physicaladdressofMVME435memory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB***ˆExitsto:RTStoDOWRITE*M*****************************************************************************M******************************************************************************WRITDATAEQU‡***0*ˆSavetheregistersthatweuseinthisroutine**WRITREGSREG‡A3/D6/D5/D0‰MOVEM.LƒWRITREGS,-(SP)**5*ˆGetthebufferlengthandthepointertothebuffer**‰MOVE.L„IOBUFLEN(A1),D5‰MOVE.L„IOBUFPTR(A1),A3**;*ˆInordertousetheMOVEPinstruction,expressthebuffer0*ˆlengthas4*q+r,whereqisthequotientand;*ˆristheremainderafterƒdividingthebufferlengthby4.8*ˆWewilluseMOVEPqtimesandMOVEr‚timesinorderto*ˆtransferthebytes.** ‰MOVE.L„D5,D6*‰AND.B…#%00000011,D6‡GetremainderintoD6!‰LSR.L…#2,D5GetquotientintoD5***ˆMovethebytes4atatime**‰WHILE†„DOŒMOVE.Lƒ(A3)+,D0ŒMOVEP.L‚D0,DATAIO0(A0) ŒSUBI.Lƒ#1,D5‰ENDW**+*ˆMovethelastofthebytesoneatatime.**‰WHILE.BƒD6#0…DOŒMOVE.Bƒ(A3)+,DATAIO0(A0) ŒSUBI.Bƒ#1,D6‰ENDW**;*ˆAfterallthebytesaretransferred,writetotheLASTWRD"*ˆregistertodelimitendofblock**‰MOVE.B„D0,LASTWRD(A0)***ˆUpdatethebufferpointer**‰MOVE.L„A3,IOBUFPTR(A1)***ˆRestoretheregisters**‰MOVEM.Lƒ(SP)+,WRITREGS‰RTSK*************************************************************************** ‰PAGE‰OPT‡PCSN****************************************************************************** ‰PAGE‰OPT‡PCSN******************************************************************************N*******************************************************************************$*ˆDOTHECONFIGURE‚ANDMOUNTCOMMAND*?*ˆTheconfigurecommandiscalledduringsysteminitialization,:*ˆandalsowhentheusercallstheMOUNTutilitywhenthat*ˆutilityiswritten).<*ˆThisisaconvenienttimetoinvestigatethetapedensity,@*ˆSincefindingthetapedensityrequiresareadfromloadpoint.B*ˆWecanalsodetermineatthistimewhetherthetransportdensity*ˆisselectableinsoftware.*B*ˆControlcomestoDOCONFGafterPROCQUEhasdeterminedthatthere@*ˆisatapeonthetransport,andthatthetransportison-line.*/*ˆAllwehavetodois(1)settheWRTPRTfield*(2)branchtoFINDDENS*.*’note:ItwouldbenicetocallFINDDENSasa,*˜subroutinebutwecannot,becauseFINDDENS2*˜doesaBSR.StoINTRTNandourstackgetsmessed.*˜upifwehaveanextrareturnaddressonit.**ˆSubroutinescalled:*<*ˆEntry:„A0=physicaladdressofmemory-mappedMTAI/Oarea/*’A1=pointertodrive'svariableblockinCCB B*’A5=physicaladdressofCCB*’A4=physicaladdressofIOCB#*’D3.B=contentsofTRSELregister*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:5*’A0=physicaladdressofmemory-mappedMTAI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*’A4=physicaladdressofIOCB#*’D3.B=contentsofTRSELregister**ˆExitsto:FINDDENS*M*****************************************************************************M****************************************************************************** DOCONFG‚EQU‡***&*ˆSettheWRTPRTfield(writeprotect)**‰BTST†#WRTPRTB,STAT1(A0)‰SNE.B…WRTPRT(A1)**,*ˆFindthetapedensityandsetMOUNTEDflag**%***†BRA.L…FINDDENSŒFallintoFINDDENSL**************************************************************************** ‰PAGE‰OPT‡PCSN******************************************************************************N********************************************************************************ˆFINDDENSCOMMAND*C*ˆControlcomestothisroutinefromDOCONFGaspartofaconfigure*ˆandmountcommand.:*ˆAtthispoint,wehavealreadysetuptheREQDENSfield,*ˆsoweknow:*ˆtheuser'srequesteddensityforwritingfromloadpoint.*?*ˆSinceweonlygettothispointafterthePROCQUEroutinehas>*ˆbeencalled,weareassuredthatthereisatapemountedand*ˆreadyonthetransport.*=*ˆThisroutinewilldeterminewhetherthetape‚waspreviously7*ˆrecordedin1600bpiornot.‚Ifnot,weassumeitwas*ˆrecordedin800bpi.B*ˆOnreturn,theTAPEDENSfieldofthedrive'svariableblockwillA*ˆbeproperlyfilledin,aswilltheMOUNTEDfieldinthedrive's*ˆvariableblock.* *ˆTAPEDENS‡XDSD1600=1600bpi†0*—XDSD800‚=800bpi‡1$*—XDSBLANK=blanktape„7ƒ(notused)*C*ˆThisroutinewillalsodeterminewhetherwecanchangedensityin*ˆsoftware(CNGDENSflag)**ˆInmoredetail:*0*’(1)Lookatbit2ofSTAT1‚toseeifweareat1*–loadpoint.‚Ifnot,settheREWFLGflag,send‚a9*–rewindcommandtothe‚controlleranddoaBSR.SINTRTN.**–Theinterruptroutine‚clearstheREWFLG.*&*’(2)Nowweknowweareatloadpoint.5*–Thetransportmustbeselectedat1600bpitogeta*–validtapedensity.**–PutXDSD800„intoTAPEDENS.**–Doareadforwardcommand.‚BSR.SINTRTN.*=*’(3)Uponreturn,weknowthattheinterruptserviceroutine0*–hasputaXDSD1600ƒintoTAPEDENSiftheCCG/ID7*–interruptwasreceived.‚Otherwise,thetapeiseither1*–blank,ƒrecordedat800bpi,orthetransportis*–stillreadingat‚800bpi.5*–Inthesecases,wewillretainXDSD800intapedens.**’(4)ClearouttheFIFO.**5*’(5)Checkthetransportdensityagain.‚Ifitis8007*–bpi,weknowthatwecannotchangetransportdensity.*7*–Ifthedensityis1600bpi,wecandeterminethetape2*–density,andweneedtodoalittlemoreworkto,*–decideifwecanchangetransportdensity.**œ(a)rewind*œ(b)select800bpi#*œ(c)readforwardƒ(clearoutFIFO)*œ(d)checktransportdensity*0* Iftransportdensityis800bpi,concludethat)* wecanindeedchangetransportdensity.* Otherwise,wecan't.*:*’(6)SettheMOUNTEDfieldinthedrive'svariableblock.*%*’(7)CallSTATCONFtoupdateIOSDST.**’(8)Rewind'*’(9)Thetapeisnowatloadpoint,and*–wecanreturn.**ˆSubroutinescalled:INTRTN*8*ˆEntry:„A0=physicaladdressofmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*’A4=physicaladdressofIOCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚R…*ˆ* *™A„P‚P…*‚P‚P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:*’D1.B=statusmessage/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB**ˆC Exitsto:MTADONE*M*****************************************************************************M*******************************************************************************FINDDENSEQU‡****<*ˆIfwearenotatloadpoint,rewindthetapetoloadpoint.**‰BTST†#LDPNTB,STAT1(A0) ‰IFˆƒTHEN“ST.B†REWFLAG(A1)“BSR.L…CKRDY“BEQ.L…MTADONE$“MOVE.B„#REWINDCD+ENABLECD,DSCMD(A0) “BSR.L…INTRTN‰ENDI***)*ˆSelecttransportwith1600bpidensity.**‰BSET†#TRSELDB,SAVESEL(A1)‰MOVE.B„SAVESEL(A1),TRSEL(A0)*=*ˆPutXDSD800KflagintoTAPEDENS.‚TheinterruptroutinewillC*ˆputXDSD1600intoTAPEDENS‚ifitreceivesaCCG/IDinterruptthat>*ˆindicatesthatthetapewasrecordedinPE(1600bpi)density.**%‰SF.B†SAVEFM(A1)‘Clearfilemarkflag.‰MOVE.B„#XDSD800,TAPEDENS(A1)‰BSR.L…CKRDY‰BEQ.L…MTADONE:* <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>*=*ˆToallowforthepossibilitythatwearereadingan800bpi?*ˆtapeat1600bpitransportdensity,setupawakeupcallhereC*ˆusingperiodicactivation(trap#0call).‚Thatway,wedon'twait@*ˆforthetapetoruntotheendofthereelbeforecomingback.@*ˆActually,testingindicatedthatIwasunabletostopthetape:*ˆinthissituation,butleavingthecodeindoesn'thurt.*ˆSET_TIMEexpects:0*’A3=addressofroutinetoexecuteuponwakeup(*’D3=numberofmillisecondsforwakeup*‰LEA‡WAKEUP(PC),A3‰MOVE.L„CONFGBLK+IOSRDTO(A1),D3‰BSR.L…SET_TIME*A*<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*$*ˆSendreadcommandtotheformatter*‰MOVE.B„#RDFWDCMD,GRCMD(A0) ‰BSR.L…INTRTN1‰SF.BƒTIMEFLAG(A5)‹CleartheTIMEFLAGtoindicate**¦thatwereturnedhereeithernormallyor*¦throughawakeupcall.**>*ˆNowforthemomentoftruth.‚Thereadcommandhasbeendone.7*ˆLet'scheckthetransportdensity.‚Ifitis‚1600bpi,%*ˆthenwecandeterminetapedensity.***‰TST.B…STAT1(A0)‰IFˆ†THEN†It's1600bpi/“MOVE.B„#XDSD1600,TRANDENS(A1)ˆUpdatetransport *ºdensity.J*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>**œNOTE*<*ˆWeassumethatatapeiseitherrecordedin1600bpiorin *ˆ800bpi.*?*ˆIcoulddiscovernosure-firewaytotellthedifference,and:*ˆitisimportantthatwerecordatapedensityof800bpi*ˆincasethat'swhatwehave.*:*ˆWhatIdiscoveredwas,ifatapewasrecordedin800bpi8*ˆandreadin1600bpi,thenfilemarksarenotdetected.*D*ˆThisnullifiestheneedforablanktapeequate,butmaybesomeone*ˆelsecanuseitlater.*<*ˆHereisthecodethatwasremovedsinceitdoesnotdothe*ˆjob.*C*ˆAlso,lookingforendoftapedoesn'twork,becausethetransport:*ˆstopsitselfƒafterreadingseveralinchesofblanktape.*(**‘IF.B†TAPEDENS(A1)……#XDSD1600ˆTHEN**›BTST†#FIEMPB,STAT2(A0) **›IFƒƒTHENŽBufferhasbytes** MOVE.B„#XDSD800,TAPEDENS(A1)**›ENDI**›TST.B…SAVEFM(A1)**›IFƒƒTHENŽTapenotblank**¡MOVE.B„#XDSD800,TAPEDENS(A1)**›ENDI**‘ENDI**J*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>**=*ˆSavetheOKmessagethatwewillsendtoMTADONEinSAVEMSG!*ˆareaofdrive'svariableblock.***“MOVE.B„#ISTAOK,SAVEMSG(A1)**;*ˆDeterminewhetherornotwecanchangetransportdensity.***(*ˆFirst,rewind,ifweareatloadpoint.*%%%%%%%%%%%%%…BWN‡5/17/84C*ˆWemayhavereturnedherebecauseofatimeoutandmaybethetape*ˆhasn'tmoved.**“BTST†#LDPNTB,STAT1(A0) “IF‚‚THEN˜ST.B†REWFLAG(A1)˜BSR.L…CKRDY˜BEQ.L…MTADONE$˜MOVE.B„#REWINDCD+ENABLECD,DSCMD(A0) ˜BSR.L…INTRTN“ENDI**)*ˆNext,selecttransportdensity800bpi.***“BCLR†#TRSELDB,SAVESEL(A1)“MOVE.B„SAVESEL(A1),TRSEL(A0)***ˆNext,readforward.**“BSR.L…CKRDY“BEQ.L…MTADONE:* <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>*=*ˆToallowforthepossibilitythatwearereadingan800bpi?*ˆtaC peat1600bpitransportdensity,setupawakeupcallhereC*ˆusingperiodicactivation(trap#0call).‚Thatway,wedon'twait@*ˆforthetapetoruntotheendofthereelbeforecomingback.$*ˆThisdoesn'twork,seenoteabove.*ˆSET_TIMEexpects:0*’A3=addressofroutinetoexecuteuponwakeup(*’D3=numberofmillisecondsforwakeup*LEA‡WAKEUP(PC),A3MOVE.L„CONFGBLK+IOSRDTO(A1),D3**BSR.SˆSET_TIME MOVE.B„#RDFWDCMD,GRCMD(A0) BSR.L…INTRTNSF.B†TIMEFLAG(A5)**ˆNow,checktransportdensity.9*ˆIfSTAT1hasitshighorderbitset,thenthetransport>*ˆdensityis800bpiandwesucceededinchangingthedensity.1*ˆOtherwise,wedidn't.Settheflagaccordingly.**“TST.B…STAT1(A0)“SMI.B…CNGDENS(A1) zcWlZtH|K„JŒI”NœI¤R¬N´U¼OÄVÌAÔJÜ>äTìJôEüR Y R L H $S ,I 4R <B D>**,*ˆRe-selectthetransportwithtapedensity.**%“IF.B†TAPEDENS(A1)ˆ†#XDSD800THENBCLR†#TRSELDB,SAVESEL(A1)“ELSEBSET†#TRSELDB,SAVESEL(A1)“ENDI“MOVE.B„SAVESEL(A1),TRSEL(A0)**‰ELSE**.“MOVE.B„#XDSD800,TRANDENS(A1)‰Updatetransport *ºdensity'“SF.B†CNGDENS(A1)‰Can'tchangedensity.*I*<<<<<<<<<<<<<< commented out 11/30/83 >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>3****MOVE.B„#ISTASEL,SAVEMSG(A1)ŠSaveerrormessage*K*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>‰ENDI**C*ˆSincewehavenowdeterminedtapedensity,andweknowthestatus**ˆofCNGDENS,wecansettheMOUNTEDflag.C*ˆOr,weknowthatwecan'tchangetransportdensity,soitdoesn't!*ˆmatterifweknowtapedensity.**ŠST.B†MOUNTED(A1)***ˆUpdateIOSDST**‰MOVE.L„CONBLOCK(A1),D6**:*ˆWearegoingtocallSTATCON1toupdatetheIOSDSTfield6*ˆandafewotherfieldsintheIOCBforthetask,but>*ˆSTATCON1changesA0topointtotheIOSATWfieldoftheIOCB?*ˆsoweneedtosaveouroldA0andrestoreitafterwereturn.***ŠMOVE.L„A0,-(SP)ŠBSR.L…STATCON1ŠMOVE.L„(SP)+,A0***ˆRewind*%%%%%%%%%‰bwn‡5/17/84*ˆIfnecessary...***‰BTST†#LDPNTB,STAT1(A0) ‰IFƒƒTHENŽST.B†REWFLAG(A1)ŽBSR.L…CKRDYŽBEQ.L…MTADONE$ŽMOVE.B„#REWINDCD+ENABLECD,DSCMD(A0) ŽBSR.L…INTRTN‰ENDI**+**‡INHIBMTAŒInhibitinterruptsattheboard'**‡ENABLEnableinterruptsatourlevel* *ˆPutthesavedmessageintoD1.**‰MOVE.B„SAVEMSG(A1),D1*‰BRA.L…MTADONEM***************************************************************************** ‰PAGE‰OPT‡PCSN******************************************************************************N******************************************************************************* *ˆSET_TIME*;*ˆThisroutinesetsupanddoesatrap0calltogeneratea?*ˆwakeupcall.‚Wedothisbeforewegiveareadcommandwhenwe+*ˆaretryingtoestablishthetape‚density.E*ˆWealsodothisforotherreadcommands,space,search,andrewind.B*ˆBydoingthis,wetryto‚preventthetapefromgoingalltheway<*ˆtoendoftapeincasewereadan800bpitapeat1600bpi7*ˆtransportdensity.‚However,itdidn'tworkontheold*ˆtransportthatwetestedon.B*ˆWealsoallowourselvesachancetotimeoutbeforeIOSsendsits@*ˆHALTIOcommand,incaseaninterruptdoesn'toccurasexpected.***ˆSubroutinescalled:**ˆEntry:„A5=addressofCCB *’A3=addressofwakeuproutine.*’D3=numberofmillisecondsforwakeupcall.*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚*‚*‚P*™A„*‚*…P…P**™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister**ˆExit:*"*ˆExitsto:RTStocallingroutine*M*****************************************************************************M*****************************************************************************SET_TIMEEQU‡**SET_RED GSREG„D0-D2/A0-A1TST.L†D3”Areweaskingfor0*°milliseconds?"BEQ.S†SET_NOIfso,therewillbe*°noexeccall./MOVEM.L„SET_REGS,-(SP)ˆSaveregistersusedfor*°trapcall$MOVE.L…#T0RQPA,D0ŒD0<---directiveCLRˆD1/MOVE.B…CCBPPRIO(A5),D1‡D1<---interruptlevel!MOVE.L…A5,D2‘D2<---CCBaddress'MOVE.L…A3,A0‘A0<---addressofwakeup,MOVE.L…D3,A1‘A1<---no.ofmillisecondsto*¸waitforwakeupTRAP‡#EXEC BRA.S†SET_WAT1Žrequestaccepted)MOVEM.L„(SP)+,SET_REGSˆRestoreregisters-SET_NOŠSF.B‡TIMEFLAG(A5)ŠrequestnotacceptedBRA.S‡SET_RETSET_WAT1ˆEQUˆ*)MOVEM.L„(SP)+,SET_REGSˆRestoreregisters***ˆSettheTIMEFLAG*‘ST.BƒTIMEFLAG(A5) ** SET_RET‚EQU‡*‰RTS D********************************************************************‰PAGE‰OPT‡PCSN******************************************************************************N********************************************************************************ˆWAKEUP*9*ˆTheentrypointsforthisroutine‚aregiventotheexec/*ˆwhenwedoarequestforperiodicactivation.*G*ˆThisroutineiscalledfromFINDDENSwhenwedoareadfromloadpoint*ˆtodeterminetapedensity.B*ˆItispossiblethatwithablanktape,thetransportmaykeepon;*ˆreadingtotheendofthetape.Wetrytopreventthisby+*ˆstoppingitafterashortperiodoftime.***ˆSubroutinescalled:*8*ˆEntry:„D1containsrequestIDwhichwehavemadeequal*’totheaddressoftheCCB5*’D0containsnumberofintervalsrepresentedbythis *’activation.*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„P‚P*™A**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:**ˆExitsto:*M*****************************************************************************M*****************************************************************************WAKEUPƒEQU„**RTEREGS‚REG‡D2-D7/A3-A5)‰MOVEM.LƒRTEREGS,-(SP)‡Savetheregisters*<*ˆWeputthecontentsofA5intotherequestIDwhenwemade.*ˆthecall,sonowwecangetitbackfromD1.*#‰MOVE.LD1,A5’A5<--‚addressofCCB*0*ˆSeeifthenormalreturnhasbeenaccomplished* ‰TST.B‚TIMEFLAG(A5)‹Ifnot,then ‰IF‚‚THEN ***%%%%%%%%%‰BWN‡5/17/84)SF.B‰TIMEFLAG(A5)ˆCleartheflagtoshow*°thatthewakeupwascalled0MOVE.LˆCCBCHB(A5),A0†A0<---addressofmemory-*°mappedI/O0MOVE.LˆIOQUEUE(A5),A1…A1<--addressofdrive's*°variableblock.*ST.B‚RTEFLAG(A5)SetRTEflag(checkedin *°INTRTN)MOVE.LˆINTSWTCH(A5),A3BSR.LSTOPTAPE“Stopthetape&JMP‚(A3)˜Jumptocontinuationaddress* ‰ENDI*‰MOVEM.Lƒ(SP)+,RTEREGS‰RTE*A*****************************************************************‰PAGE‰OPT‡PCSN******************************************************************************N******************************************************************************* *ˆWAKEUP2*9*ˆTheentrypointsforthisroutine‚aregiventotheexec/*ˆwhenwedoarequestforperiodicactivation.*?*ˆThisroutineiscalledfromDOREAD,SPACE,ERASE,SEARCH,and*ˆDOREWIND.=*ˆWearetryingtopreventthesystemfromhangingforalong&*ˆtimeincaseaninterruptismissed.=*ˆThesystemwillsendusaHALTIOcommandforthesecommandsD*ˆwhenthetimesetintheIOSRTOhasrunout,butweneedashorter*ˆtimethanthatfortheread.**ˆSubroutinescalled:*8*ˆEntry:„D1containsrequestIDwhichwehavemadeequal*’totheaddressoftheCCB5*’D0containsnumberofintervalsrepresentedbythis *’activation.*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„P‚P*™A**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:*IfwegotoMTADONE:#*A0=addressofmemory-mappedI/O(*A1=addressofdrive'svariableblock*A5=addressofCCB*D1.B‚=‚Timeouterrormessage***ˆExitsto:*M******************************D ***********************************************M***************************************************************************** WAKEUP2‚EQU„**)‰MOVEM.LƒRTEREGS,-(SP)‡Savetheregisters*<*ˆWeputthecontentsofA5intotherequestIDwhenwemade.*ˆthecall,sonowwecangetitbackfromD1.*#‰MOVE.LD1,A5’A5<--‚addressofCCB*0*ˆSeeifthenormalreturnhasbeenaccomplished* ‰TST.B‚TIMEFLAG(A5)‹Ifnot,then ‰IF‚‚THEN ***%%%%%%%%%‰BWN‡5/17/84)SF.B‰TIMEFLAG(A5)ˆCleartheflagtoshow*°thatthewakeupwascalled0MOVE.LˆCCBCHB(A5),A0†A0<---addressofmemory-*°mappedI/O0MOVE.LˆIOQUEUE(A5),A1…A1<--addressofdrive's*°variableblock.*ST.B‚RTEFLAG(A5)SetRTEflag(checkedin *°INTRTN)MOVE.LˆINTSWTCH(A5),A3BSR.LSTOPTAPE“Stopthetape/SF.B‰REWFLAG(A1)‰Cleartherewindflagincase*°wehavearewindcommand.*MOVE.Bˆ#ISTATO,D1‰D0<---timeoutmessage$BRA.LMTADONE”Finishupthecommand* ‰ENDI*‰MOVEM.Lƒ(SP)+,RTEREGS‰RTE*A***************************************************************** ‰PAGE‰OPT‡PCSN******************************************************************************N*******************************************************************************4*ˆDOTHEREADFORWARDCOMMAND--DIRECTMODE10/3/83*@*ˆControlcomestothisroutinefromPROCQUEwhenwehavearead-*ˆforwardcommandtosendtotheMTAadapter.**5*ˆWearealsoguaranteedthatthetapeisnotatEOT.*"*ˆThisroutinedoesthefollowing:**4*’(1)Putmaximumnumberofreadtriesinto‚NUMREAD.*’(2)CleartheSAVEERR,SAVEFM *–PutbufferlengthintoSAVELEN1*’(3)Checkready.Ifthetransportisnotready,*–gotoMTADONE*’(3.5)Selectdirectmode.3*’(4)WritetheRDFWDCMDintotheGRCMDregisterof *–theMTA.!*’(4.5)Clearthehalffullflag.*’(5)DoaBSR.StoINTRTN.8*’(6)Executionwillcontinuewhentheinterrupthandler,*–hassentuscontrol.Thiswill‚happenwhen**–(a)thefnbsyinterrupthasoccurred,or+*–(b)thehalffullinterrupthasoccurred..*’(6.5)Ifwereceivethehalffullinterrupt,.*–read2Kbytesofdataandbranchbackto4.5*–Otherwise,continueon."*’(7)ChecktheSAVE___variables.)*œifSAVEFM,putISTAEOFmessageintoD1,*ŸandgotoMTADONE*œifSAVEERR#*Ÿsubtract1fromtheNUMREADvalue*ŸifNUMREAD‚isnotzero*¢doaspacereversecommand*¢BSR.SINTRTN*¢loopbackto3*Ÿelse*¢transferdata*¢put‚ISTACRC‚intoD1*¢andgotoMTADONE*else(ifnoerrors)*¢checkforendoftape*¢transferdata*¢gotoMTADONE**.*ˆSubroutinescalled:‚INTRTN,READDATA,READ2K*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oares/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚R *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:…D1=statusmessage5*’A0=physicaladdressofMTAmemory-mappedI/Oares/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB**ˆExitsto:MTADONE*M*****************************************************************************M****************************************************************************** DORDFWD‚EQU‡***G*ˆWewilldotheread,andiftapedensityisnotthesameastransport$*ˆdensity,thentheremaybeerrors.<*ˆTheCONFGBLK+IOSRDTfieldoftheconfigurationareainthe*ˆdrive'svariableblockholds.*ˆthenumberoftimesthatwewillreadbeforeB*ˆreturningwithaparityerror.‚Whenwedoaconfigureandmount,-*ˆwemakesurethatthisvalueisatleast1.9*ˆWekeepthenumreadvalueinavariableinthedrive'sB*ˆvariableblockbecausewewillbedoingaBSR.StoINTRTNduring=*ˆthiscommand,whichreturnsustoCMR.‚Whenwereturn,only,*ˆregistersA0,A1,andA5willbeasbefore.**'‰MOVE.B‚CONFGBLK+IOSRDT(A1),NUMREAD(A1)*0*ˆSaE vethebufferpointerandthebufferlength.** ‰MOVE.L„IOBUFLEN(A1),SAVELEN(A1)**%%%%%%%%‚DEBUGƒBWNƒ5/29/84‰CLR_TRƒRTR*RDLOOP***%%%%%%%%%%%%%…bwn‡5/17/84"*ˆPuttheOKmessageintoSAVEMSG.9*ˆREAD2Kwilloverwritewithabufferoverflowmessageif*ˆthereisabufferoverflow.*‰MOVE.B„#ISTAOK,SAVEMSG(A1)**%%%%%%%%%%%%%%%%%%%%%%%**?*ˆCleartheflagsthattheinterrupthandlerwillsetifeither;*ˆoftheinterruptsforparityerrororforfilemarkdetect*ˆarereceived*ˆAlsoendoftape.**‰SF.B†SAVEERR(A1)‰SF.B†SAVEFM(A1)‰SF.B†SAVEEOT(A1)**8*ˆGet‚theoriginal‚bufferpointerandthebufferlength.** ‰MOVE.L„SAVELEN(A1),IOBUFLEN(A1)!‰MOVE.L„IOBUFLOC(A1),IOBUFPTR(A1)**(*ˆChecktoseeifthetransportisready**‰BSR.L…CKRDY‰BEQ.L…MTADONE**.*ˆSendthereadforwardcommandtotheMVME435***%%%%%%%%%%%%%ƒBWN12/4/84A*ˆSometapedrives(whichdonotfollowthePERTECspecforwhichC*ˆtheMVME435boardwasdesigned)sendoutbytesinsuchawaythatE*ˆwhentheMVME435triestoreadthebyte,itreadstheonefollowing@*ˆinstead.‚Thussomebytesgetcorrupted.‚Thiswasonlyobserved?*ˆtohappenindirectmodeat100ips,1600bpi,ontheVME/10.*G*ˆThereforethedriverwaschangedsothatiftheuserbufferlengthisD*ˆgreaterthan4096bytes,thenwereadindirectmode,otherwisewe*ˆreadinbufferedmode.*$‰IF.L„IOBUFLEN(A1)‚‚#MAXBUFƒTHEN'MOVE.B„D0,DIRSL(A0)’Selectdirectmode‰ENDI *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*%%%%%%%%%%%„bwnƒ5/23/84**ˆSetupatimeoutforthereadB*ˆIfwedon'tgetanexpectedinterrupt,thenthewakeupcallwill>*ˆstopthetapeandsendustoMTADONEwithatimeout‚message.*‰LEA„WAKEUP2(PC),A3‰MOVE.LCONFGBLK+IOSRDTO(A1),D3‰BSR.L‚SET_TIME*%%%%%%%%%%%%%%%%%%%%%%%%%%%‰MOVE.B„#RDFWDCMD,GRCMD(A0)*%%%%%%%%%%‚DEBUG‚BWN‚5/29/84 ‰TRACE…R1,RTRRDWAITƒEQU‡*+‰SF.B†HALFFULL(A1)’Clearflagforhalf-full'‰ST.BƒTIMEFLAG(A5)•Setflagfortimeout ‰BSR.L…INTRTN*%%%%%%%DEBUGBWN‚5/29/84 ‰TRACE…R2,RTR*‰SF.BƒTIMEFLAG(A5)•Clearflagfortimeout. **;*ˆChecktoseeifwereceivedtheFIFOhalffullinterrupt.9*ˆUponreturnfromtheinterrupt,D0.BcontainstheSTAT2*ˆregistercontents.**‰TST.B…HALFFULL(A1) ‰IFƒ„THEN*C*<<<<<<<<<<<<<<<<<<<<<<<INSERT11/30/83…>>>>>>>>>>>>>>>>>>>>>>>>>>*7*ˆTherewasahalffullinterrupt,butjusttobesure,*ˆlet'stesttheotherbit.**“BTST†#FIHAFB,D0 “IFƒƒTHEN*$*ˆGivethecontrolleranotherchance**%%%%% DEBUG BWN 5/29/84 ‰TRACE…R3,RTR ˜BRA.S†RDWAIT4*<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>“ENDI*I*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> “BSR.L…READ2K “BRA.S†RDWAIT‰ENDI*I***************************************************************************ˆTHEREADCOMPLETED*F***********************************************************************+**‡INHIBMTAŒInhibitinterruptsattheboard'**‡ENABLEnableinterruptsatourlevel**ˆUpdatetransportdensity***%%%DEBUG‚BWN6/5/84 ‰TRACE…R4,RTR‰CKTRDEN**=*ˆTestforfilemarkdetect.‚Ifthiswasafilemark,wedonot6*ˆtransferanydata,butwestillmustcleartheFIFO.**‰TST.B…SAVEFM(A1) ‰IFƒƒTHENŽMOVE.B…#ISTAEOF,D1EOFmessage#ŽBTST‡#FIEMPB,STAT2(A0)‡FIFOempty?*ŽWHILE†…DOIfno,readintobitbucket™MOVE.B„DATAIO0(A0),D0™BTST†#FIEMPB,STAT2(A0)ŽENDWŽBRA.L†MTADONE‘GotoMTADONE‰ENDI**2*ˆTest‚forparityerrors.Iftherearenone,‚check*ˆforendoftape.**‰TST.B…SAVEERR(A1)‰IFˆƒTHEN“NoparityerrorsG************************************************************************&*ˆTHEREARENOERRORSONTHETAPEREAD3*ˆTHEREMAYBEABUFFEROVERFLOWMESSAGEINSAVEMSG*J***************************************************************************/*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< INSERT 11/30/83*.***ŽBTST„#E EOTB,STAT1(A0)‰CheckforendoftapeG*ˆThetransportmustbeforciblystoppedatendoftape,andifwewere=*ˆnotfastenough,thenwemayhavegonepastendoftape,so*ˆchecktheflag.*‘TST.BƒSAVEEOT(A1)*D*<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*%%%%%%%%%‰BWN‡5/17/84‘IF†ƒAND.B™SAVEMSG(A1)‚‚#ISTAOKƒTHENœMOVEQB…ISTAEOV,D1‘ENDI*:*<<<<<<<<<<<<COMMENTEDOUTƒ11/30/83>>>>>>>>>>>>>>>>>>>>>*'*ˆComparetapeandtransportdensities.****MOVE.B†TRANDENS(A1),D0*!**IF.B‚TAPEDENS(A1)…ƒD0ƒTHEN**™MOVEQB„ISTADEN,D1**ENDI*B*<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*‘BSR.L…READDATAŽTransferdata*°READDATAwillputbuffer*°overflowmessageinD1*°ifnecessary.‘BRA.L…MTADONE‰ENDI*G************************************************************************#*ˆTHEREAREERRORSONTHETAPEREAD*B*******************************************************************F*ˆIfthereisaparityerror,subtract1fromthenumberofreadtries1*ˆthatareleft.‚Iftherearenoreadtriesleft,?*ˆtransferthedata,thenputtheparityerrormessageintoD1.***%%%%%%%%%%DEBUG‚BWNƒ5/29/84 ‰TRACE…ER,RTR *%%%%%%%%%‰SUBQ.B„#1,NUMREAD(A1) ‰IFˆ†THEN“BSR.L…READDATA“MOVEQB„ISTACRC,D1“BRA.L…MTADONE‰ENDI **>*ˆIfwehaveaparityerrorandwestillhavesometriesleft,@*ˆdoaspacereversetothebeginningoftheblockandtryagain***‰BSR.L…CKRDY/*<<<<<<<<<<<<‚INSERTED1/3/84>>>>>>>>>>>>>>>>> ‰IFƒ‚THENMOVE.B‚#ISTACRC,D1BRA.LƒMTADONE‰ENDI+*<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>‰MOVE.B„#SPREVCMD,GRCMD(A0) ‰BSR.L…INTRTN**,*ˆResetadapterboardbeforestartingagain.!*ˆEnableinterruptsattheboard.**‰MOVE.B„#MTARSTCD,DSCMD(A0)‰MOVE.B„SAVESEL(A1),TRSEL(A0) ‰ENABLMTA* ‰BRA.L†RDLOOP I*************************************************************************‰PAGE‰OPT‡PCSN******************************************************************************N********************************************************************************ˆREAD2K*B*ˆThisroutinereads2kbytesfromtheFIFOandputsthemintothe@*ˆuserbuffer,ifthereisroom,orintoD0ifthereisnoroom.*C*ˆWeonlygettothisroutineifweknowthatthereareatleast2K*ˆbytesintheFIFO.*B*ˆREAD2KputsabufferoverflowmessageintoSAVEMSGifnecessary.**ˆSubroutinescalled:*/*ˆEntry:„A0=addressofmemory-mappedI/Oarea(*’A1=addressofdrive'svariableblock*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚*‚*‚*‚*‚**™A„P‚P**™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister*.*ˆExit:…A0=addressofmemory-mappedI/Oarea(*’A1=addressofdrive'svariableblock*,*ˆExitsto:RTStocallingroutine(DORDFWD)*M*****************************************************************************M******************************************************************************READ2KƒEQU‡**RD2KREGSREG‡A3/D0-D5&‰MOVEM.LƒRD2KREGS,-(SP)†Saveregisters*-‰MOVE.L„IOBUFLEN(A1),D3…D3<---bufferlength.‰MOVE.L„IOBUFPTR(A1),A3…A3<---bufferpointer**7*ˆSetupD5<---quotientofbufferlengthdividedby4:*ˆSetupD4<---remainderwhenbufferlengthdividedby4** ‰MOVE.L„D3,D4‰AND.L…#3,D4 ‰MOVE.L„D3,D5‰LSR.L…#2,D5**4*ˆSetupD2<---halfFIFOlength,namely2048bytes**‰MOVE.W„#HAFBUF,D2*%%%%%%%%%%%%%ƒBWN‚12/4/84*8*ˆOntheVME/10wemustreadthebytesfastertokeepup:*ˆsowhenthereisenoughroomintheuser'sbuffer,speed-*ˆuptheloopbydoingmoreMOVEP'sinarow.*<‰IF.L‚D3‚‚#HAFBUFƒTHEN†Roomfor2048bytesinuser'sbufREPEAT/“MOVEP.L„DATAIO0(A0),D0…Move32bytesatatime/“MOVE.L…D0,(A3)+‹andrepeattheloop512times.“MOVEP.L„DATAIO0(A0),D0“MOVE.L…D0,(A3)+“MOVEP.L„DATAIO0(A0),D0“MOVE.L…D0,(A3)+“MOVEP.L„DF ATAIO0(A0),D0“MOVE.L…D0,(A3)+“MOVEP.L„DATAIO0(A0),D0“MOVE.L…D0,(A3)+“MOVEP.L„DATAIO0(A0),D0“MOVE.L…D0,(A3)+“MOVEP.L„DATAIO0(A0),D0“MOVE.L…D0,(A3)+“MOVEP.L„DATAIO0(A0),D0“MOVE.L…D0,(A3)+“SUBI.L…#32,D2UNTIL‚SUBI.L†#HAFBUF,D3 ‰ELSE*@*ˆWeexecuteherebecausethereisnotenoughroomintheuser's*ˆbufferfor2048bytes.*@*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*?*ˆAslongasthereareatleast4bytesintheFIFOand4bytes<*ˆinthebuffer,movebytes4atatimefromFIFOtobuffer.**%‰WHILEƒD2‚‚#0ƒAND.LƒD5‚‚#0ƒDO“MOVEP.LƒDATAIO0(A0),D0“MOVE.L„D0,(A3)+“SUBQ†#4,D2 “SUBQ.L„#1,D5 “SUBQ.L„#4,D3‰ENDW**&*ˆIftherearebytesleftintheFIFO,8*ˆreadthenext4bytesfromtheFIFO,andputtheminto'*ˆeithertheuserbufferorbitbucket.**‰IFˆD2‚‚#0ƒTHEN“FOR.B…D1=#1‚TO‚#4ƒDOIF.BƒD4‚‚#0ƒTHEN§MOVE.B„DATAIO0(A0),(A3)+ §SUBQ.L„#1,D3 §SUBQ.B„#1,D4ELSE*%%%%%%%%%%ˆbwn‡5/17/84*ˆBufferoverflow!!!§MOVE.B„#ISTABO,SAVEMSG(A1)*%%%%%%%%%%%%%%%%%%%%%%%%§MOVE.B„DATAIO0(A0),D0ENDI“ENDF“SUBQ†#4,D2‰ENDI**3*ˆAslongastherearebytesleftintheFIFO,read*ˆthemintothebitbucket.**‰WHILE…D2‚‚#0ƒDO“MOVEP.LƒDATAIO0(A0),D0“SUBQ†#4,D2‰ENDW*%*%%%%%%%%%%%%%%%%%%%%%%%%‚bwn‚12/4/84*'*ƒNeedanENDItocloseoffconditional*‰ENDI*9*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%***ˆUpdatebufferlengthandbufferpointer.**‰MOVE.L„D3,IOBUFLEN(A1)‰MOVE.L„A3,IOBUFPTR(A1)**)‰MOVEM.Lƒ(SP)+,RD2KREGS‡Restoreregisters‰RTS L****************************************************************************‰PAGEN******************************************************************************N********************************************************************************ˆREADDATAFROMFIFOTOBUFFER*A*ˆThisroutineiscalledfromDORDFWDwhenweexpecttofinddata<*ˆintheFIFO,andwanttotransferittothebufferpointed*ˆtobyIOBUFPTR.*;*ˆWehavetotransferonebyteatatime,becausewehavenoE*ˆwayofknowinghowmanybytesareintheFIFO,andwehavetocheck*ˆforbufferoverflow.*B*ˆAlso,wehavetobesuretoreadallthebytesoutofthebuffer**ˆoritwillinterferewiththenextread.*B*ˆOnexit,IOBUFPTRwillpointtothebytefollowingthelastbyte*ˆtransferred.**ˆSubroutinescalled:*8*ˆEntry:„A0=physicaladdressofmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*ˆ* *™A„P‚P…***™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister**ˆExit:1*’A0=physicaladdressofmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB**ˆExitsto:RTStoDORDFWD*M*****************************************************************************M*******************************************************************************READDATAEQU‡***)*ˆSavetheregistersusedinthisroutine**READREGSREG‡A3/D3/D0‰MOVEM.LƒREADREGS,-(SP)**#*ˆD3<---numberofbytesinbuffer*ˆA3<---pointertobuffer*‰MOVE.L„IOBUFLEN(A1),D3‰MOVE.L„IOBUFPTR(A1),A3**%%%%%%%%%%%%%%„bwn‡5/17/84>*ˆPutSAVEMSG,whichmayhaveabufferoverflowmessage,oran!*ˆendofvolumemessage,intoD1.*‰MOVE.B„SAVEMSG(A1),D1**%%%%%%%%%%%%%%%%%*@*ˆAslongasthereisabyteintheFIFOandroominthebuffer, *ˆmovethebyteintothebuffer.5*ˆIfthereisnoroominthebuffer,puttheoverflow*ˆmessageintoD1.**READLOOP.‰BTST†#FIEMPB,STAT2(A0)Onboardbufferempty? ‰BNE.S‡READDONE–Ifso,finished.*‰IF.Lƒ#0‚‚D3ƒTHENŽRoominuserbuffer?/MOVE.B„DATAIO0(A0),(A3)+†Ifso,transferbyte. SUBQ.L„#1,D3BRA.S†READLOOPLoopback‰ENDI-‰MOVE.B„#ISTABO,D1Ifnoroominuserbuffer,*°putbufferoveF rflow*°messageinD1.*9*ˆHerewereadbytesintobitbuckettocleanuptheFIFO8*ˆThismaynotbenecessary,sincewecleanouttheFIFO!*ˆforthenextcommandinPROCQUE*ˆItcaneasilybeNOPedout.**READOFLOEQU‡**6*ˆKeepacountofthenumberofbytesleftintheFIFO*ˆfordebuggingpurposes.** ‰ADDQ.L„#1,D31‰MOVE.B„DATAIO0(A0),D0†Readbytesintobitbucket‰BTST†#FIEMPB,STAT2(A0)‰BEQ.S‡READOFLO**1*ˆUpdatethebufferpointerandrestoreregisters**READDONEEQU‡**‰MOVE.L„A3,IOBUFPTR(A1)‰MOVEM.Lƒ(SP)+,READREGS‰RTS*@****************************************************************‰PAGE‰OPT‡PCSN******************************************************************************N******************************************************************************* *ˆSTOPTAPE*+*ˆStopthetapebyresettingtheformatter.7*ˆThisroutineisusedwhenwehaveanerrorcondition.***ˆSubroutinescalled:*/*ˆEntry:„A1=addressofdrive'svariableblock#*’A0=addressofmemory-mappedI/O*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D**™A„P‚P**™P=parameterregister*™R=returnregister!*™*=savedandrestoredregister**ˆExit:*"*ˆExitsto:RTStocallingroutine*L*****************************************************************************STOPTAPEEQU‡*7‰MOVE.B„#FORDISCD,DSCMD(A0)‰Resettheformattertostop *®thetape(‰MOVE.L„D4,-(SP)”Savetheregistersused*@*ˆSoatthispointwewillbusywaituntilthetapedrivestops.*STOPWAITMOVE.L„#WAITCNT,D4STOPLOOPSUB.L…#1,D4‰BNE.S‡STOPLOOP1‰BTST†#FNBSYB,STAT1(A0)ƒSeeifformatternotbusy'‰BEQ.S‡STOPWAITŒIfformatterbusy,wait+‰MOVE.B„#FORDISCD,DSCMD(A0)ƒResetformatter(‰MOVE.B„STAT2(A0),D0‹ReadSTAT2toclear"‰MOVE.L„(SP)+,D4ŒRestoreregisters‰RTS*4**************************************************** ‰PAGE N******************************************************************************N********************************************************************************ˆINTERRUPTRETURNROUTINE*C*ˆControlreachesthispointintheMTdriverwhenwehavefinishedB*ˆexecutingaco-routinesegmentandwishtoreturntothesystem.H*ˆWereturncontroltothesystemwheneverwemustwaitforacontrollerA*ˆactivity,namely,afteranycommandthatwehavewrittentotheE*ˆGRCMDregisteroftheMTA,andafterrewindwhenwearewaitingfor*ˆtheBOTinterrupt.E*ˆThisroutineisalsocalledfromIDLELOOPwhentherearenoentries*ˆintheIOQUEUE.*(*ˆThefollowingisdoneinthisroutine:*!*’movetopofstackintoINTSWTCH;*”(sothatwe'llpickupatattheproperplacewhenweget*•interrupted)*’iftheRTEFLAGisset,then *•clearit.*•restoretheregistersthatweresavedinthe*—timerroutineA3-A5/D2-D6*•RTE!*’iftheRTEFLAGisnotset,then8*–restoretheregistersthatweresavedatthebeginning&*˜oftheinterrupthandlerA4/A3/D1-D6 *–enableinterruptsatourlevel9*–settheSR.Cbittoindicatethatwehaveprocessedthe*™interrupt*–RTStoCMR***ˆSubroutinescalled:‚none*8*ˆEntry:„A0=physicaladdressofmemory-mappedMTAarea*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D*™A**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:*!*ˆExitsto:ReturntoCMRviaRTS*M*****************************************************************************M******************************************************************************FINTRTNƒMOVE.Lƒ(SP)+,INTSWTCH(A5)…Thisroutineiscalledasanordinary'*¦subroutine,‚so‚thestackcontainsthe(*¦addressoftheco-routinesegment‚that'*¦should‚be‚executedinresponsetothe%*¦nextinterrupt.‚We‚get‚that‚address&*¦out‚of‚the‚stack,andweputitinto*¦theinterruptswitch. $*¦Itisimportantthatinterruptsbe'*¦maskedatourinterruptlevelatthis*¦time. **D*ˆIfwG earrivedatthisroutinebecauseofatimeoutinterrupt,thenH*ˆwehavedifferentregisterstorestorethanifwearrivedherebecause@*ˆoftheusualcircumstances.Whenthesystemsendsusatimeout@*ˆinterrupt,D0,D1,A0,andA1havealreadybeensaved.ƒTheseareC*ˆdifferentfromtheregistersthatCMRsaves,namelyD0,A0,A1,A5.**‰TST.B…RTEFLAG(A5) ‰IFˆ†THEN“SF.B†RTEFLAG(A5)“MOVEM.Lƒ(SP)+,RTEREGS“RTE‰ENDI**=*ˆIfcontrolreachesthispoint,thenwehaveanormalreturn** (‰MOVEM.L‚(SP)+,RTSREGSˆRestoreregisters***¦SettheCARRYbitofthestatusregister*¦beforereturning1‰MOVEQ„#1,D0control‚to‚CMR.‚SettingtheSR.Cbit ‰SUBQ.B„#2,D0)‰RTS›indicatesthatwe‚have‚processed‚the*¦interrupt.(*¦WecouldalsobereturningtoCOMMANDS&*¦iftheMTINTroutinewascalledasa$*¦subroutinewhentherewasjustone*¦entryintheIOQUEUE. L****************************************************************************‰PAGEN******************************************************************************N*********************************************************************************ˆMTADONE‚--FINISHPROCESSINGQUEUEENTRY*C*ˆControlcomestothetopofthisco-routinewhentheMTdriveris@*ˆreadytofinishprocessingthecurrententryoftheI/Oqueue.A*ˆEitherwe'vecompletedtheI/OtransactionthatisspecifiedbyD*ˆcurrententryofthequeue,orwe'verunintosomeproblemthatwe*ˆcan'tsolve.5*ˆWe'llqueueanI/Ocompletion„eventtotheattached>*ˆtask,andwe'llremovethecurrententryfromtheI/Oqueue.?*ˆIftheI/Oqueuehasanotherentry,we'llloopbackandstart*ˆprocessingit.*$*ˆInterruptsareenableduponentry.%*ˆInterruptsaredisableattheboard*1*ˆInmoredetail,theroutinedoesthefollowing:*-*ˆ(1)getvariablesoutofI/Opacketsothat*’D0=IOBUFLOC*’D3=IOBUFPTR*’A1=IOBUFTCB*’A3=DCBPNTR*’A4=IOCBPTR*B*ˆ(2)Computethenumberofdatabytesactuallytransferred,store *ŒintotheIOSLENfieldofIOCB.*?*ˆ(3)Updatethetransportdensity,andiftheWRITEFLGisset,**ŒsetTAPEDENSequaltotransportdensity.*5*ˆ(4)BSR.SQEVENTIwithA5=physicaladdressofCCB*A4=IOCBPTR *A3=DCBPTR*D2.B=eventtype*D1.B=statusvalue*=*ˆ(5)Decrementthecountoutstandingoperationsforthetask!*Œthatownsthebuffer(TBCIOCNT)*B*ˆ(6)removethefrontentryfromtheIOQUEUEandsetA1=address8*ŒofdriveblockofnextentryinIOQUEUEifthereisone*D*ˆ(7)reduceIOQCNTqueuecountpointer.‚IfthereisstillanactiveB*ŒentryintheIOQUEUE,BRA.StoPROCQUE,otherwisegotoIDLELOOP.***ˆSubroutinescalled:QEVENTI**ˆEntry:5*’A0=pointertomemory-mappedI/OspaceforMVME435/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*D1.B=statusvalue*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™D„*‚P‚**™A„P‚P‚*‚*‚*‚P‚*‚***™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:5*’A0=pointertomemory-mappedI/OspaceforMVME435/*’A1=pointertodrive'svariableblockinCCB.*—fornextcommandtoexecute,ifthereisone*’A5=physicaladdressofCCB*6*ˆExitsto:IDLELOOProutineiftheI/Oqueueisempty3*’PROCQUEiftheI/Oqueuecontainsanactiveentry*M*****************************************************************************M*******************************************************************************-*ˆWeputthenormaleventtype($70)intoD2.** MTADONE‚EQU‡*‰MOVE.B„#XPSNRM,D2**>*ˆMovelongwordsfromthedrive'svariableblocktoregisters=*ˆusingtheMOVEMinstruction.‚Itisimportantthattheorder3*ˆofthewordsinthevariableblockbeasfollows: *’IOBUFLOC *’IOBUFPTR *’IOBUFTCB *’DCBPNTR *’IOCBPTR"*ˆTheregisterassignmentwillbe:*’D0<---IOBUFLOC*’D3<---IOBUFPTR*’A1<---IOBUFTCB*’A3<---DCBPNTR*’A4<---IOCBPTR**G MTAREGS‚REG‡D0/D3/A1/A3/A4‰MOVEM.LƒIOBUFLOC(A1),MTAREGSL1‡SETŽIOBUFLOCL1‡SETŽIOBUFPTRL1‡SETŽIOBUFTCBL1‡SETŽDCBPNTRL1‡SETŽIOCBPTR**=*ˆComputetheactuallengthofthedatatransferandputinto*ˆtheIOSLENfieldoftheIOCB.*‰SUB.L…D0,D3‰MOVE.L„D3,IOSLEN(A4)****0*ˆCallQEVENTItoqueueanI/Ocompletionevent.*ˆQEVENTIexpectstofind:*’A5=physicaladdressofCCB*’A4=physicaladdressofIOCB*’A3=physicaladdressofDCB*’D2.B=eventtype*’D1.B=error/statusmessage**‰BSR.L‡QEVENTI**;*ˆDecrementthecountofoutstandingI/Ooperationsforthe;*ˆtaskthatownstheI/Obuffer(ortheIOCBinthecaseof!*ˆastatusorconfigurecommand).**‰SUB.B…#1,TCBIOCNT(A1)**=*ˆWeareabouttoremovethefrontentryfromtheIOQUEUEand=*ˆmovetheotherentriesupbyone.‚Inordertodothisusing6*ˆtheMOVEMinstruction,wewillusesevenofthedata*ˆregisters.**MTAIOQR‚REG‡D1-D7‰MOVEM.LƒIOQUEUE+4(A5),MTAIOQR‰MOVEM.LƒMTAIOQR,IOQUEUE(A5)**F*ˆNowitisimportanttoputtheaddressofthedrive'svariableblock,*ˆintoA1forapossiblebranchtoPROCQUE.*ˆPROCQUErequires: *’A0=memory-mappedI/Oaddress(*’A1=addressofdrive'svariableblock*’A5=addressofCCB**‰MOVE.L„IOQUEUE(A5),A1‰SUB.W…#4,IOQCNT(A5)**>*ˆIfthereisanotherentryintheIOQUEUE,thengotoPROCQUE:*ˆtostartprocessingthatentry.‚Otherwise,fallintothe*ˆIDLELOOP.**‰BHI‡PROCQUEIDLELOOPEQU‡***E*ˆControlcomestothispointiftherearenoentriesintheIOQUEUE.C*ˆBSR.StoINTRTNputstheMTIDLEaddressintoINTSWTCH.‚Duringthe?*ˆinterruptserviceroutine,ifwereceiveaformatternotbusyE*ˆ(operationcomplete)interrupt,wejumptotheaddressinINTSWTCH.D*ˆIfwereceiveaformatternotbusyinterruptwhenwehadnotgivenD*ˆacommandtothecontroller,thenwewillsettheMTADOWNflagand *ˆreturn.** ‰BSR.S‡INTRTNMTIDLEƒST.B†MTADOWN(A5)‰BRA.S†IDLELOOPN****************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆDOTHEERASECOMMAND*B*ˆControlcomestothiscommandfromPROCQUEwhenwehaveanerase%*ˆcommandtosendtotheMTAadapter.*"*ˆThisroutinedoesthefollowing:*%*’(1)PuttheerasecommandintoD4.B1*’(2)Branchtothecommonroutinethathandles.*–eraseandwritefilemark.**ˆSubroutinescalled:**<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oares/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB#*’D3.B=contentsofTRSELregister*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™DŠ*‚P‚R *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:…D4.B=erasecommand**ˆExitsto:FM_ERAS_COMM*M*****************************************************************************M****************************************************************************** DOERASE‚EQU‡**;*ˆPuttheerasecommandintoD4,thenbranchtotheroutine)*ˆthathandleseraseandwritefilemark.*‰MOVE.B„#ERASECMD,D4‰BRA.S…FM_ERAS_COMM**K***************************************************************************‰PAGEN******************************************************************************N******************************************************************************* *ˆDOTHEWRITEFILEMARKCOMMAND*A*ˆControlcomestothiscommandfromPROCQUEwhenwehaveawrite*ˆfilemark%*ˆcommandtosendtotheMTAadapter./*ˆPROCQUEcheckstosee‚thatwearenotatEOT.*"*ˆThisroutinedoesthefollowing:*)*’(1)PutwritefilemarkcommandintoD42*’(2)Branchtothecommaonroutinefor‚writefile*–markanderase.**ˆSubroutinescalled:**<*ˆEntry:„A0=physicH aladdressofMTAmemory-mappedI/Oares/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB#*’D3.B=contentsofTRSELregister*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™DP‚R *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister*&*ˆExit:…D4.B=writefilemarkcommand**ˆExitsto:FM_ERAS_COMM*M*****************************************************************************M****************************************************************************** DOWRTFM‚EQU‡***:*ˆMovethewritefilemarkcommandintoD4.Bandbranchto7*ˆthecommon‚routineforwritingfilemarkanderasing.**‰MOVE.B„#WRTFMCMD,D4-***†BRA.L†FM_ERAS_COMM‡FallintoFM_ERAS_COMM*B******************************************************************‰PAGEN******************************************************************************N********************************************************************************ˆFM_ERAS_COMM*E*ˆControlcomestothiscommandfromDOERASEandDOWRTFM‚whenwehaveA*ˆeitheraneraseorawritefilemarkƒcommandtosendtotheMTA *ˆadapter.*"*ˆThisroutinedoesthefollowing:*!*’(1)Checkforwriteprotection.2*’(2)Checkforloadpoint.‚Ifatloadpoint,select+*–densityforwritingandsettheloadpoint*–flag.0*’(3)WritethecommandintotheGRCMDregister.*’(4)BSR.StoINTRTN8*’(5)Executionwillcontinuewhentheinterrupthandler5*–hassentuscontrol.Thiswillonlyhappenwhenthe*–fnbsyinterrupthasoccurred.1*–Updatethetransportdensity,andifthiswasa0*–writefromloadpoint,updatethetapedensity.*’(6)Checkforerrors.2*’(7)ChecktheSTAT1registertoseeifweareat*–endoftape,andifso,*ŸputISTAEOVintoD1*’(8)GotoMTADONE*$*ˆSubroutinescalled:INTRTN,SELECT**<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oares/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB#*’D3.B=contentsofTRSELregister *’D4.B=commandtowritetoMTA*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7 *™D„*‚R‚*‚P‚P *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:…D1.B=statusmessage**ˆExitsto:MTADONE*M*****************************************************************************M*****************************************************************************FM_ERAS_COMM‡EQU‡****ˆCheckforwriteprotection *‰MOVE.B„#ISTAWP,D1‰BTST†#WRTPRTB,STAT1(A0)‰SNE‡WRTPRT(A1)‰BNE.S‡MTADONE**ˆCheckforloadpoint.**‰BTST†#LDPNTB,STAT1(A0)1‰SNE‡LDPNTFLG(A1)ˆSetflagifwe'reatloadpoint,*¦clearitotherwise.****ˆIfatloadpoint, *ˆcallSELECT‚to‚changedensity.**‰IFˆ…THEN.S.TST.BƒREQDENS(A1)…Ifuserrequestsadensity,IF‚ƒTHEN.S2“MOVE.B„CONFGBLK+IOSDEN(A1),D0…SelectuserdensityELSE.S)“MOVE.B„#XDSD1600,D0†elseselect1600bpiENDI BSR.L‡SELECT‰ENDI****ˆCleartheerrorflag**‰SF.B†SAVEERR(A1)****ˆCleartheSAVEEOTflag**‰SF.B†SAVEEOT(A1)*-‰BSR.L…CKRDYŽChecktoseeifthetransportis/‰BEQ.S‡MTADONEready,andifnot,gotoMTADONE*¦with'notready'message. *%%%%%%%%%%%%%%%%%%%‚BWN…5/23/84*"*ˆSetupatimeoutforthecommand**‰LEA„WAKEUP2(PC),A3‰MOVE.LCONFGBLK+IOSWTO(A1),D3‰BSR.L‚SET_TIME*%%%%%%%%%%%%%%%%%%%%%%%%%%%3‰MOVE.B„D4,GRCMD(A0)ˆMovecommandintoMTAregister ‰BSR.L‡INTRTN**=*ˆControlreturnwhenacommandcompletioninterrupthasbeen*ˆdetected.*+**‡INHIBMTAŒInhibitinterruptsattheboard'**‡ENABLEnableinterruptsatourlevel*8*ˆUpdatetransportdensity,andtapedensityifthiswas*ˆawritefromloadpoint.*%‰SF.BƒTIMEFLAG(A5)‹Cleartimeoutflag*‰CKTRDEN‰MOVE.B„TRANDENS(A1),D2‰TST.B…LDPNTFLG(A1) ‰IFˆ†THEN“MOVE.B„D2,TAPEDENS(A1)“SF.B†LDPNTFLG(A1)‰ENDI***ˆCheckforerrors**‰MOVE.B„#ISTACRC,D1‰TST.B…SH AVEERR(A1)‰BNE.L‡MTADONE**$‰CKEOT™Checktoseeifweareatend *¦oftape,andifso,returnthe*¦'endofvolume'message.*@*ˆIfweranoverendoftape,thentheSAVEEOTflagwillbeset.**‰TST.B…SAVEEOT(A1)‰BNE.L‡MTADONE -‰MOVE.B„#ISTAOK,D1ŠOtherwise,returnthe'ok' *¦message.‰BRA.L†MTADONEN******************************************************************************‰PAGEN******************************************************************************N********************************************************************************ˆDOTHEREWINDCOMMAND*B*ˆControlcomestothisroutinefromPROCQUEwhenwehavearewind%*ˆcommandtosendtotheMTAadapter.*ˆWemaybeatloadpoint.**ˆIndetail:*’(1)SetREWFLAG.8*’(2)WritetheREWINDCDintotheDSCMDregisterofMTA.*’(3)BSR.StoINTRTN7*’(4)Uponreturn,weknowthattheloadpointinterrupt4*–hasbeenreceived.‚Thereshouldbea1inSAVEBOT."*’(5)PutISTABOTmessageintoD1.*’(6)GotoMTADONE***ˆSubroutinescalled:INTRTN*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D‡R*™A‡P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:…D1=statusmessage**ˆExitsto:MTADONE*M*****************************************************************************M******************************************************************************DOREWINDEQU‡***-*ˆChecktoseeifwearealreadyatloadpoint**‰MOVE.B„#ISTAOK,D1‰BTST†#LDPNTB,STAT1(A0)‰BNE.L‡MTADONE**5*ˆSincewearenotatloadpoint,itissafetorewind**%‰ST.B†REWFLAG(A1)‰Settherewindflag‰BSR.L‡CKRDY‰BEQ.L‡MTADONE*%%%%%%%%%%%%%%%ƒbwnˆ5/23/84*ˆSetuptheTimeout*‰LEA„WAKEUP2(PC),A3‰MOVE.LCONFGBLK+IOSRWTO(A1),D3‰BSR.L‚SET_TIME*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%$‰MOVE.B„#REWINDCD+ENABLECD,DSCMD(A0) ‰BSR.L‡INTRTN)‰SF.BƒTIMEFLAG(A5)‹Clearthetimeoutflag**9*ˆWereturnfromtheinterruptwhenbeginningoftapehas*ˆbeenreached./*ˆTheinterrupthandlerclearstherewindflag.*+**‡INHIBMTAŒInhibitinterruptsattheboard'**‡ENABLEnableinterruptsatourlevel*‰MOVE.B„#ISTAOK,D1‰BRA.L†MTADONEN****************************************************************************** ‰PAGEN******************************************************************************N*******************************************************************************)*ˆDOTHESEARCHFILEMARKFORWARDCOMMAND*B*ˆControlcomestothisroutinefromPROCQUEwhenwehaveasearch*ˆfilemark-*ˆforwardcommandtosendtotheMTAadapter.**ˆPROCQUE‚guarantees4*ˆthatwearenotatEOTwhenwestartthisroutine.*"*ˆThisroutinedoesthefollowing:*8*ˆ(1)PutthesearchfilemarkforwardcommandintoD4.B*ˆ(2)BranchtoSEARCH**ˆSubroutinescalled:*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™DR *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:…D4.B=command**ˆExitsto:SEARCH*M*****************************************************************************M******************************************************************************DOSFMFWDEQU‡***>*ˆPutthesearchfilemarkforwardintoD4.Bandbranchtothe*ˆcommonsearchroutine.**‰MOVE.B„#SFMFWDCD,D4 ‰BRA.S†SEARCH*J**************************************************************************‰PAGEN******************************************************************************N*******************************************************************************)*ˆDOTHESEARCHFILEMARKREVERSECOMMAND*B*ˆControlcomestothisroutinI efromPROCQUEwhenwehaveasearch*ˆfilemark-*ˆreversecommandtosendtotheMTAadapter.**ˆPROCQUE‚guarantees4*ˆthatwearenotatBOTwhenwestartthisroutine.*"*ˆThisroutinedoesthefollowing:*0*ˆ(1)PutthesearchfilemarkcommandintoD4.B#*ˆ(2)BranchtotheSEARCHroutine.**ˆSubroutinescalled:*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™DR *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:…D4.B=commandforMTA**ˆExitsto:SEARCH*M*****************************************************************************M******************************************************************************DOSFMREVEQU‡**‰MOVE.B„#SFMREVCD,D4)***†BRA.L†SEARCHFallintoSEARCHroutine O******************************************************************************* ‰PAGEN******************************************************************************N*******************************************************************************4*ˆDOTHESEARCHFILEMARKFORWARDORREVERSE‚COMMAND*5*ˆControlcomestothisroutine‚whenwehaveasearch*ˆfilemarkforwardorreverse%*ˆcommandtosendtotheMTAadapter.**"*ˆThisroutinedoesthefollowing:*6*ˆ(1)CleartheSAVEFMvariableinthevariableblock./*ˆ(2)WritesthecommandtotheGRCMDregister.*ˆ(3)BSR.StoINTRTN:*ˆ(4)Uponreturntothisroutine,thefnbsyinterrupthas*Œoccurred."*ˆ(5)ChecktheSAVE___variables:**’ifSAVEFM%*•putISTAOKintoD1,exittoMTADONE*’ifendoftape&*•putISTAEOVintoD1,exittoMTADONE*’ifbeginningoftape&*•putISTABOVintoD1,exittoMTADONE*’ifneitheroftheabove%*•putISTATO‚intoD1,exittoMTADONE%*•inthiscase,thetapemaybeblank***ˆSubroutinescalled:INTRTN*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB#*’D4.B=‚commandtosendtotheMTA*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D‡RˆP *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister**ˆExit:…D1=statusmessage**ˆExitsto:MTADONE*M*****************************************************************************M*****************************************************************************SEARCHƒEQU‡**$‰SF.B†SAVEFM(A1)ŠClearfilemarkflag(‰SF.B†SAVEEOT(A1)‰Clearendoftapeflag**‰BSR.L…CKRDYIfthetransportisnotready)‰BEQ.L‡MTADONEŽputanerrormessageinD1*§andgotoMTADONE***%%%%%%%%%%%%%%%ƒbwnˆ5/23/84*ˆSetuptheTimeout*‰LEA„WAKEUP2(PC),A3‰MOVE.LCONFGBLK+IOSSRTO(A1),D3‰BSR.L‚SET_TIME*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%,‰MOVE.B„D4,GRCMD(A0)‹SendcommandtoMVME435 ‰BSR.L‡INTRTN**ˆSF.B†TIMEFLAG(A5)‹Clearthetimeoutflag*A*‰Controlreturnsherewhenwehavereceivedacommandcompletion*‰interrupt.*+**‡INHIBMTAŒInhibitinterruptsattheboard'**‡ENABLEnableinterruptsatourlevel*7*‰Checkforfilemark--inthiscaseitisnotanerror**‰MOVE.B„#ISTAOK,D1‰TST.B…SAVEFM(A1)‰BNE.L‡MTADONE**+*ˆIfnotafilemark,checkforendoftape.:*ˆTheCKEOTmacrowillputamessageintoD1andbranchto'*ˆMTADONEifweareattheendoftape.G*ˆThereversecommand,ofcourse,shouldnevercauseamovementtoEOT.**‰CKEOT*1*ˆIncaseweranpastendoftape,checktheflag.**‰TST.B…SAVEEOT(A1)‰BNE.L‡MTADONE**>*ˆIncasethiswasthereversecommand,checkforbeginningof*ˆtape.**‰CKBOT**0*ˆIfwehaveneitherafilemarknorendoftape,@*ˆnorbeginningoftape(forthereversecommand),thecontroller9*ˆhaspossiblygeneratedatimeoutifitreadblanktape.**‰MOVE.B„#ISTATO,D1‰BI RA.L†MTADONE J************************************************************************** ‰PAGEN******************************************************************************N********************************************************************************ˆDOTHESPACEFORWARDCOMMAND*A*ˆControlcomestothisroutinefromPROCQUEwhenwehaveaspace-*ˆforwardcommandtosendtotheMTAadapter.**ˆPROCQUEalsoguarantees4*ˆthatwearenotatEOTwhenwestartthisroutine.**"*ˆThisroutinedoesthefollowing:*-*ˆ(1)PutthespaceforwardcommandintoD4.B;*ˆ(2)BranchtoSPACE,thecommonroutineforspaceforward*Œandspacereverse.**ˆSubroutinescalled:*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™DR *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister*$*ˆExit:…D4.B=spaceforwardcommand**ˆExitsto:SPACE*M*****************************************************************************M****************************************************************************** DOSPFWDEQU‡* *‰MOVE.B„#SPFWDCMD,D4‰BRA.S…SPACE*H************************************************************************ ‰PAGEN******************************************************************************N********************************************************************************ˆDOTHESPACEREVERSECOMMAND*A*ˆControlcomestothisroutinefromPROCQUEwhenwehaveaspace-*ˆreversecommandtosendtotheMTAadapter.**ˆPROCQUEalsoguarantees4*ˆthatwearenotatBOTwhenwestartthisroutine.**"*ˆThisroutinedoesthefollowing:*-*ˆ(1)PutthespacereversecommandintoD4.B;*ˆ(2)BranchtoSPACE,thecommoncommandforspaceforward*andspacereverse.**ˆSubroutinescalled:*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™DR *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister*$*ˆExit:…D4.B=spacereversecommand**ˆExitsto:SPACE*M*****************************************************************************M****************************************************************************** DOSPREVEQU‡**‰MOVE.B„#SPREVCMD,D4'***†BRA.L†SPACEŽFallintoSPACEroutine*G***********************************************************************‰PAGEN******************************************************************************N*******************************************************************************/*ˆDOTHESPACEREVERSEORSPACEFORWARDCOMMAND*4*ˆControlcomestothisroutine‚whenwehaveaspace>*ˆreverseorspaceforwardcommandtosendtotheMTAadapter.***"*ˆThisroutinedoesthefollowing:**ˆ(1)ClearSAVEFM/*ˆ(2)WritesthecommandtotheGRCMDregister.*ˆ(3)BSR.StoINTRTN:*ˆ(4)Uponreturntothisroutine,thefnbsyinterrupthas*Œoccurred."*ˆ(5)ChecktheSAVE___variables:**’ifSAVEFM&*•putISTAEOFintoD1,exittoMTADONE*’ifbeginningoftape&*•putISTABOVintoD1,exittoMTADONE*’ifendoftape&*•putISTAEOVintoD1,exittoMTADONE**ˆ(6)PutISTAOKintoD1,*ŒexittoMTADONE**ˆSubroutinescalled:INTRTN*<*ˆEntry:„A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*’D4.B=command*"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D‡RˆP *™A„P‚P‹P**™P=parameterregister*™R=returnregister*™*=destroyedregister*;*ˆExit:…A0=physicaladdressofMTAmemory-mappedI/Oarea/*’A1=pointertodrive'svariableblockinCCB*’A5=physicaladdressofCCB*’D1=statusmessage**ˆExitsto:MTADONE**J M*****************************************************************************M******************************************************************************SPACEƒEQU‡* *$‰SF.B†SAVEFM(A1)ŠClearfilemarkflag*+‰BSR.S‡CKRDYIfthetransportisnotready,)‰BEQ.L‡MTADONEŽputanerrormessageinD1*§andgotoMTADONE***%%%%%%%%%%%%%%%ƒbwnˆ5/23/84*ˆSetuptheTimeout*‰LEA„WAKEUP2(PC),A3‰MOVE.LCONFGBLK+IOSSPTO(A1),D3‰BSR.L‚SET_TIME*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%,‰MOVE.B„D4,GRCMD(A0)‹SendcommandtoMVME435 ‰BSR.L‡INTRTN‰SF.BƒTIMEFLAG(A5)**A*‰Controlreturnsherewhenwehavereceivedacommandcompletion*‰interrupt.*+**‡INHIBMTAŒInhibitinterruptsattheboard'**‡ENABLEnableinterruptsatourlevel**‰Checkforfilemark>*ˆTheCKFMmacroabortstoMTADONEwiththeISTAEOFmessagein&*ˆD1iftherewasafilemarkdetected.**‰CKFM**1*‰Ifnotafilemark,checkforbeginningoftape.:*‰TheCKEOTmacrowillputamessageintoD1andbranchto'*‰MTADONEifweareattheendoftape.**‰CKBOT**ˆCheckforendoftape**‰CKEOT**<*ˆWehopeallwentwell.‚Itmaybethatwespacedoverblank(*ˆtapeandthecontrollerhastimedout.:*ˆWewillsendback"OK".‚Whenwedoareadtheerrorwill *ˆbenoticed.**‰MOVE.B„#ISTAOK,D1‰BRA.L†MTADONEL****************************************************************************‰PAGE‰OPT‡PCSN******************************************************************************N********************************************************************************ˆCKRDY*=*ˆThisroutinecheckstheSTAT1registeroftheMVME435board=*ˆtodetermineifthetransportisreadytoacceptacommand.*5*ˆWegivethetransportseveralchancestogetready.3*ˆIfitisreadyrightaway,wereturnimmediately.5*ˆOtherwise,wesetatimerforWAITRDYmilliseconds.@*ˆBeforewedothis,wesavetheaddressonthetopofthestack<*ˆsowewillbeabletoreturnuponwakeup,andalsotakeit5*ˆoffthestacksothatINTRTNwilloperateproperly.*<*ˆIfthetimerrequestisnotaccepted,wereturnrightaway!*ˆandthetransportisnotready.B*ˆOtherwise,ifthetimerrequestisaccepted,weBSR.StoINTRTN,"*ˆreturningcontroltothesystem.*=*ˆUponwakeup,wesavetheRTEregistersandsettheRTEflagA*ˆsothattheINTRTNroutinewillknowwhichregisterstorestore(*ˆandthatitshouldreturnwithanRTE.>*ˆThenwegetbackourCCBpointerintoA5,ourdataareainto-*ˆA1,andourmemory-mappedI/OareaintoA0.*:*ˆWerestoretheaddressofourcallingroutine,checkthe;*ˆreadybitoftheSTAT1registeroncemore,andRTStothe*ˆcallingroutine.****ˆSubroutinescalled:*/*ˆEntry:„A0=addressofmemory-mappedI/Oarea(*’A1=addressofdrive'svariableblock*’A5=AddressofCCB**"*ˆRegistersusage:†0‚1‚2‚3‚4‚5‚6‚7*™D„*‚R‚*‚**™A„P‚R…*…R**™P=parameterregister*™R=returnregister*™*=destroyedregister*&*ˆExit:…D1="notready"errormessage(*’A0=addressofmemory-mappedI/Oarea(*’A1=addressofdrive'svariableblock*’A5=addressofCCB*"*ˆExitsto:RTStocallingroutine*M*****************************************************************************M******************************************************************************CKRDY„EQU‡**‰BTSTƒ#READYB,STAT1(A0) ‰IF…ƒTHEN*>*ˆThetransportisnotready,sowewillsetatimerandcheck*ˆagainafterwakeup.*LEAƒCKRDWAKE(PC),A3MOVE.Lˆ#WAITRDY,D3BSR.LSET_TIMETST.BTIMEFLAG(A5)!IFƒ‚THENˆExecrequestfailed“MOVE.B…#ISTANR,D1“BTST‡#READYB,STAT1(A0)“RTSENDI.MOVE.Lˆ(SP)+,SAVEADDR(A5)Savereturnaddress BSR.L‰INTRTN**'*ˆControlreturnsherefromwakeupcall**CKRDWAKEEQU„*-MOVEM.L„RTEREGS,-(SP)‰SavetheRTEregisters'MOVE.L…D1,A5‘A5<---CCBpointersaved*¸asrequestID0MOVJ E.L…CCBCHB(A5),A0‰A0<---addressofmemory-*¹mappedI/Oarea1MOVE.L…IOQUEUE(A5),A1ˆA1<---addressofdrive's*¹variableblockST.B‡RTEFLAG(A5)‹SetRTEflag1MOVE.L…SAVEADDR(A5),-(SP)„RestorereturnaddressMOVE.B…#ISTANR,D1ŒCheckreadyBTST‡#READYB,STAT1(A0)‰ENDI‰RTS*G*********************************************************************** MTAPATCHDS.B†256‡Patcharea *‰END F**********************************************************************éé=/* =/*†MFPDRV.AF=/*H=/* Chain file to assemble MK68910 serial port driver for local ports on=/* VME120 and VME128 boards.=/*:=/* If no output argument is specified for the listing the(=/* chain file will default to MFPDRV.LS=/*=/IFC \1ƒ=ARGMFPDRV.LS=/ENDIF=/*"=ASM MFPDRV.SA,MFPDRV.RO,\1;RZ=140=/*{ Included files are:=/*ƒ9995.&.STR.EQ=/*ƒ9995.&.TCB.EQ=/*ƒ9995.&.CCB.EQ=/*ƒ9995.&.IOE.EQ=/*ƒ9995.&.NIO.EQ=/*ƒ9995.&.LV5.EQ=/*ƒ9995.&.BAB.EQ=/*ƒ9995.&.UTILITY.MC=/*ƒ9995.&.TERMCCB.EQ=/*ƒ9995.&.TERMINAL.EQ=/*ƒ9999.MK68901.MK68901.EQ=/*}=/*=ENDééééé L@MFPDRV„IDNTƒ4,0‡VERSADOSMK68901TERMINALDRIVERWITHTYPE-AHEAD=ŠTTL„MFPDRV:ƒVERSADOSMK68901TERMINALDRIVERWITHTYPE-AHEAD ŠLLENƒ120J**************************************************************************J**************************************************************************J**************************************************************************J***************************************************************************;*‰MFPDRV:ƒVERSAdosMK68901terminaldriverwithtype-ahead.*8*‰Purpose:‚VERSAdosdevicedrivertohandleasynchronous2*terminals(ofanytype)overtheMK68901chipon*thefollowingboards:*“MVME120„MVME128**‰Revisionhistory:1*10/23/84‚AllBSR'stoTERMLIBnowJSR'sincase.*šTERMLIBislocK atedmorethan32Kbytesaway.**10/17/84‚InitialreleasebyJulieHoban.*J**************************************************************************J**************************************************************************J**************************************************************************J************************************************************************** **‚XREF'sfromTERMLIB* ‰XREF†LOG_ERR‰XREF†MARK_DOWN‰XREF†RESET‰XREF†TERM_BREAK‰XREF†TERM_COMMAND‰XREF†TERM_GOT_CHAR‰XREF†TERM_INIT‰XREF†TERM_TBE‰XREF†TERM_UNRDY **‚Equatefilesincluded:* **‰STR.EQ*‰TCB.EQ*‰CCB.EQ*‰IOE.EQ*‰NIO.EQ*‰LV5.EQ1*‰BAB.EQBackgroundActivationBlockdescription.:*‰TERMCCB.EQ‰OffsetsandequatesforCCBDDPforterminals.$*‰TERMINAL.EQˆEquatesforterminals. *‰MK68901.EQ‰Devicedescription.*‰UTILITY.MC‰Macros.*ŠPAGEŠNOLISTŠINCLUDE9995.&.STR.EQŠNOLISTŠINCLUDE9995.&.TCB.EQŠNOLISTŠINCLUDE9995.&.CCB.EQŠNOLISTŠINCLUDE9995.&.IOE.EQŠNOLISTŠINCLUDE9995.&.NIO.EQŠNOLISTŠINCLUDE9995.&.LV5.EQŠNOLISTŠINCLUDE9995.&.BAB.EQŠNOLISTŠINCLUDE9995.&.UTILITY.MCŠLISTŠINCLUDE9995.&.TERMCCB.EQŠINCLUDE9995.&.TERMINAL.EQ ŠINCLUDE9999.MK68901.MK68901.EQ UL ^E f@ n< v5 ~1 †7 Ž: –= žB ¦= ®? ¶5 ¾I ÆD Î< ÖA ÞC æŠTTL‡MK68901DEVICEDESCRIPTIONŠLISTŠPAGE G*‚TheMostekMK68901Multi-FunctionPeripheral(MFP)containsasingle-C* channel USART capable of full duplex, asynchronous communication.J* The register offsets are described in the equate file MK68901.MK68901.EQF* common to both the timer and serial port on the MVME120 and MVME128.J* The bit and field definitions used to program the MK68901 for the serial%* port functions are described below. ***ˆGPIPRegisterBitDefinitions(MFP_GPIP)*-SW2†EQU0(1)=12.5Mhz(0)=10.0MhzonVME120-DTR†EQU6(1)=Deviceunready(0)=Deviceready SPC 3*4*ˆUSARTControlRegisterfielddefinitions(MFP_UCR)* * Clock rate [7]CLOCK16‚EQU%10000000 * Bits per character [6:5](BIT7…EQU%00100000‡7databits/character(BIT8…EQU%00000000‡8databits/character * Stop bits [4:3]SB1†EQU%00001000‡1stopbitSB2†EQU%00011000‡2stopbits * Parity [2:1]#PARENAB‚EQU%00000100‡Parityenable!PAREVEN‚EQU%00000010‡Evenparity SPC 3**ˆInterruptRegister(s)* 7SWMODEƒEQU3(1)=Softwaremodeend-of-interruptcontrol6UNMASKƒEQU%00011100‡UnmasktheUSARTbitsinMFP_IMRA2ENABLEƒEQU%01011100‡EnableUSARTbitsinMFP_IERA"TE‡EQU2(1)=TransmitBufferEmptyRE‡EQU3(1)=ReceiverError RC‡EQU4(1)=ReceiveBufferFull PAGE*7*ˆTranmsitterStatusRegisterBitdefinitions(MFP_TSR)*BE‡EQU7(1)=bufferemptyUE‡EQU6(1)=underrunerror5AT‡EQU5(1)=enablerxafterlastchariftxdisabled2END†EQU4(1)=endoftransmissionwithtxdisabledBRKS…EQU3(1)=sendbreak TX‡EQU0(1)=transmitterenabled5TXHI…EQU$40Tranmsitteroutput'HI'whentxdisabled5TXLO…EQU$20Tranmsitteroutput'LO'whentxdisabled SPC 3*4*ˆReceiverStatusRegisterBitdefinitions(MFP_RSR)*BF‡EQU7(1)=bufferfullOE‡EQU6(1)=overrunerrorPE‡EQU5(1)=parityerrorFE‡EQU4(1)=framingerrorBRKR…EQU3(1)=receivedbreak"CIP†EQU2(1)=character-in-processSS‡EQU1(1)=syncstripenableRX‡EQU0(1)=receiverenable *%*ˆEquatesforModuleControlRegister*MCR†EQU$F40000‰AddressofMCR-SW6†EQU7(1)=12.5Mhz(0)=10.0MhzonVME1281CTS_120‚EQU1Bittoset/clearCTS*line(output)BUNR_120‚EQU1<*‰includedisaparametertellingthenumberofextrapagesof>*‰memorytoincludeintheCCB,andinformationdescribingthe*‰revisionofthedriver.*L**************************************************************************** ŠSECTION‚0ŠOPT„BRS MFPDRV: *D*‚Servicevectortable.‚NoticethatthesevaluesarerelativetotheC*‚beginningofthedriversothemechanismisposition-independent!*<ŠDC.LƒINTERRUPT-MFPDRVƒAddressofinterruptserviceroutine.8ŠDC.LƒCOMMAND-MFPDRV…Addressofcommandserviceroutine.4ŠDC.LƒINIT-MFPDRVˆAddressofinitializationroutine.ŠDC.Lƒ0’Reserved. **‚OtherCMRparameters.*7ŠDC.BƒEXTCCBSZ‹#ofextrapagesintheCCB.‚TheCCBmay)*§beanysizefrom1to256pages(apage'*§is256bytes):‚ifthisfieldis0,it*§willbe1page,etc.ŠDC.Bƒ0,0,0ŽReserved.ŠDC.Lƒ0,0,0ŽReserved. **‚Revisioninfo:*/ŠDC.Bƒ'102384'‹DateoflastassemblyasMMDDYY.1ŠDC.Bƒ''Spaceindicatesnopatchesto.LOfile.)ŠDC.Bƒ'4'MajorVERSAdosrevisionnumber.*‰PAGEO********************************************************************************+*ˆJumptableforusebythegenericTERMLIB*O******************************************************************************* ‰BRA.L…PUT_CHAR ‰BRA.L…CK_TBE‰BRA.L…DDP_RESET‰BRA.L…SETUP‰BRA.L…CLOCK_RESET‰BRA.L…GET_STAT‰BRA.L…DDP_STOP‰BRA.L…DDP_UNSTOP‰BRA.L…DDP_BEG_BREAK‰BRA.L…DDP_END_BREAK‰PAGEJ**************************************************************************J**************************************************************************J****************************************************************************‰INITIALIZATIONROUTINE*>*‰ThisroutineiscalledbyCMRwhenthechannelisallocated.9*‰Itspurposeistosetupthingsforcommandserviceand7*‰interruptservice.‚Themajorfunctionsperformedare:*;*Š1.Takesoveradditionalvectorsrequiredbythisdriver.@*Š2.Device-IndependentinitializationinthecalltoTERM_INIT.<*Š3.Determineifwe'rethedriverfortheVME120orVME128.9*Š4.Device-Dependentinitializationinacallguardedto#*DO_INITtoinitializethedevice.*@*‰WegotherethroughaJSRfromCMR,andwillexitwithanRTS.>*‰AllregistershavebeensavedbyCMRandmaybeusedfreely.?*‰Entryisatinterruptlevel0,andweareinsupervisormode.**‰Entry:‚A5=addressofCCB.*:*‰Calls:‚TERM_INITinthegenericterminaldriverTERMLIB.*#*‰Exit:ƒCMR(viaRTS)ifallisOK.'*‘KILLERifexecwon'tallocatememory,.*’orcan'tgetbackgroundroutineentrypoint.*J**************************************************************************J********************************************************************L ******J**************************************************************************ŠDS…0 *D*ƒTheMK68901has4vectorsthatsupporttheUSARTpartofthechip.C* Currently, there is no way that CMR can process 4 vectors for oneA* channel. We take care of the matter here by reading the addressC* stored away in the vector we gave CMR via the channel data block,F* and store that address in the other 3 vectors that CMR has not takenH* over. Actually, the driver only uses 3 of the four vectors. The vectorH*number$6CistheonewestoredintheCCB.‚WeneedtoputtheaddressD*fromvectornumber$6Cintovectornumbers$6Band$6A.‚ThevectorF* number $69 is used to report transmit errors and is not supported by* this driver.*ŠPAGEINIT:*#*‚Takeovertheadditionalvectors.*&ŠMOVEQ.L#0,D0Clearworkingregister.:ŠMOVE.BCCBVECT(A5),D0…GetthevectornumberfromourCCB.-ŠMULUƒ#4,D0ŽMulitplyby4togettheaddress.'ŠMOVE.LD0,A0ŽCopytoaddressregister.0ŠMOVE.L(A0),-(A0)‰Copycontentstoaddress-4.0ŠMOVE.L(A0),-(A0)‰Copycontentstoaddress-4.*>*‚Performthedevice-independentinitializationbycallingthe'*‚genericroutineTERM_INITinTERMLIB.*.‰JSR‡TERM_INIT‹Dothedevice-independentstuff2‰IFƒƒTHEN…SomethingwentwrongwithTERM_INIT.4‰IFƒƒTHEN„Theexeccallfailedandwecannotget!*œthescheduler'sentrypoint!!!ŽTR0$.KILLER‚,‰ELSERTSThechannelisdown!!‰ENDI‰ENDI*F*‚ReadthehighorderbyteoftheModuleControlRegistertodetermineD*‚ifwe'rethedriverontheMVME120orMVME128.‚ThehighorderbyteB*‚oftheMCRisguaranteedtobe$FFontheMVME120board.Setthe *‚properdrivercodeinourCCB.*‰MOVE.WMCR,D0‘ReadtheMCR..‰CMP.B‚#$FF,D0Highorderbyteguaranteed$FF..‰BNE.S‚INIT128Branch,itmustbetheMVME128.5‰MOVE.B#120,DRV_FLAG(A5)†SetdriveflagforMVME120. ‰BRA.S‚INIT200Doneforthe120.*‰Wegetenteredherewhentheattachedtask(IOS)invokesCMR?*‰viaaTRAP1withanINITIATEI/Oparameterblocktoprocess.>*‰CMRhasalreadycheckedtheCMRparameterblocktoensureit<*‰resideswithintheaddressspaceoftheattachedtask.‚IOSA*‰hasalreadyvalidatedtheIOCB,exceptforthebufferaddresses *‰therein.*@*‰WegotherethroughaJSRfromCMR,andwillexitwithanRTS.>*‰AllregistershavebeensavedbyCMRandmaybeusedfreely.?*‰Entryisatinterruptlevel0,andweareinsupervisormode.*5*‰Entry:A2=physicaladdressofCMRparameterblock*A5=physicaladdressofCCB*9*‰Calls:TERM_COMMANDingenericterminaldriverTERMLIB.*3*‰Exit:‚D0=resultsofparameterblockvalidation:3*•always0inourcase,indicatingitwasOK,since2*•IOSwillnotsendusanyrequestexceptHALTI/O/*•ifwearealreadybusy,andCMRmakesallthe*•otherchecks.**J**************************************************************************J**************************************************************************J************************************************************************** COMMAND: *,*‚Performanydevice-dependentstuffhere...* *=*‚Wehavereceivedacommand,soweknowthereissomeoneoutI*‚theretotalkto.‚Iftheguywhoreportsbreaksisasleep,wakehimup.* %ŠJSR…TERM_COMMAND†PerformthecommandŠRTS—returntoL CMR.ŠPAGEJ**************************************************************************J**************************************************************************J****************************************************************************‰INTERRUPTHANDLINGROUTINE*<*‰ThisroutinecompletesI/Orequestsstartedbythecommand:*‰serviceroutine.‚Itisenteredattheinterruptpriority;*‰levelofinterruptsonthischannel,andisessentiallya9*‰subroutinetothefirstlevelinterrupthandlerinCMR.*:*‰Entry:D0,A0,A1havebeensavedbyCMRandareavailable*A5=addressofCCB*9*‰ExitisalwaysviaRTS,whichtakesusbacktoCMR.‚The3*carrybitisexaminedbyCMRtodeterminewhether7*thedriverhandledtheinterruptorwhetheritshould4*passtheinterruptontothenextguyinthechain*onthatvector:*='Ihandledit'**‰Stack:*(A7)+8... *(A7)+4longwordreturnaddress6*(A7)ƒlongwordsavedcontentsofD1(mustberestored*—beforeexittoCMR)*J**************************************************************************J**************************************************************************J************************************************************************** INTERRUPT:3ŠMOVE.LCCBCHB(A5),A1†A1<--addressofourdevice.=ŠMOVE.BMFP_ISRA(A1),D0„D0<--interruptin-serviceregister.9ŠBEQ.S‚NOT_FOR_ME‰Ifnobitsareset,interruptnotmine. "ŠPUSH.LD1‘Getsomeworkingspace.7ŠMOVE.BMFP_RSR(A1),D1…Copyofreceivestatusregister.4ŠBCLRƒ#RC,MFP_ISRA(A1)ƒHavewereceivedacharacter?)ŠBNE.S‚RCABranchtoprocesscharifyes. )ŠBCLRƒ#RE,MFP_ISRA(A1)ƒWasthisanerror?-ŠBNE.S‚INTERRBranchtoprocesserrorifyes. ;ŠMOVE.BMFP_TSR(A1),D1…Copyoftransmitterstatusregister.4ŠBCLRƒ#TE,MFP_ISRA(A1)ƒIsourtransmitbufferempty?1ŠBNE.S‚TBEBranchtoprocessemptybufferifyes.+ŠPOP.L‚D1‘Ifwegethere,mustnotbemine. NOT_FOR_MEŠMOVEQ‚#0,D0ŠADDQƒ#1,D0ŠRTSŠPAGEJ***************************************************************************)*‰TRANSMITBUFFEREMPTYINTERRUPTHANDLER*@*‰TheMK68901'stransmitbufferjustbecameempty,soifwehave?*‰morecharacterstosendwecandoitnow.Thedevicedoesnot@*‰generateTBEinterruptswhilethetransmitterisenabled(edge<*‰sensitive),sothereisnoinstructiontodisableithere.*%*‰Entry:A1=addressofourdevice..*A5=addressofCCB-*D1.B=copyoftransmitterstatusregister.*9*‰Calls:TERM_TBEinthegenericterminaldriverTERMLIB.*<*‰Sincethisisnotasubroutine,registersatexitarejust-*‰theentryrequirementsofthenextroutine.*O******************************************************************************* TBE:8ŠJSRƒTERM_TBEŒCalldevice-independentroutinetofinish.(ŠBRA.SINT_EXITŒExitfromtheinterrupt.ŠPAGEJ***************************************************************************(*‰RECEIVEDCHARACTERAVAILABLEINTERRUPT*@*‰TheMK68901hasjustreceivedacharacter,anditisavailable=*‰forreading.‚Wewilldothatnow,andtheresultwillgoin$*‰thereceivequeueifthere'sroom.*"*‰Entry:A1=addressofourport.*A5=addressofCCB**D1.B=copyofreceiverstatusregister.*>*‰Calls:TERM_GOT_CHARinthegenericterminaldriverTERMLIB.*<*‰Sincethisisnotasubroutine,registersatexitarejust-*‰theentryrequirementsofthenextroutine.*J************************************************************************** RCA:5ŠMOVE.BMFP_UDR(A1),D0‡GetthecharfromtheMK68901.5ŠJSR„TERM_GOT_CHARˆDothedevice-independentstuff...)ŠBRA.S‚INT_EXITExitfromthisinterrupt.ŠPAGEJ***************************************************************************#*‰FOUNDERRORONRECEIVEDCHARACTER*=*‰TheMK68901detectedanerrorintheprocessofreceivinga<*‰character.‚Weneedtorecordthisinformationsothatwhen<*‰thecoM rrespondingdataisrequestedfromthereceivequeue*‰wecanreportanerror.*$*‰Entry:A1=addressofourdevice.*A5=addressofCCB**D1.B=copyofreceiverstatusregister.*7*‰Calls:LOG_ERRandTERM_BREAKinthegenericTERMLIB.*<*‰Sincethisisnotasubroutine,registersatexitarejust-*‰theentryrequirementsofthenextroutine.*J************************************************************************** INTERR:.ŠMOVE.BMFP_UDR(A1),D0ˆReadthedataregister. (ŠBTST‚#BRKR,D1Havewereceivedabreak?1ŠIF„THENŽIfthereceivedbreakbitisset...:‹TST.B‚BRK_FLAG(A5)‰Seeifwe'vealreadysenttheevent...3‹BNE„INT_EXITFlagsetindicatesitssent,soexit.!‹BRA.S‚PROCBRKŽProcessthebreak!ŠENDI /ŠBTSTƒ#OE,D1Perhapsthiswasanoverrunerror.0ŠIF…THENIftheoverrunerrorbitisset.../‹PUT_BYTEOVERRUN,D0‰Getthepropererrorcode.‹JSR„LOG_ERRŽLogtheerror.+‹BRA„INT_EXITAndexitfromthisinterrupt.ŠENDI &ŠBTST„#PE,D1Howaboutaparityerror?/ŠIF†THENŒIftheparityerrorbitisset...0‹PUT_BYTEPAR_FRAM,D0ˆGetthepropererrorcode.‹JSR„LOG_ERRŽLogtheerror.*‹BRA„INT_EXITAndexitfromtheinterrupt.ŠENDI )ŠBTST„#FE,D1Lastcallforframingerror.0ŠIF†THENŒIftheframingerrorbitisset...0‹PUT_BYTEPAR_FRAM,D0ˆGetthepropererrorcode.‹JSR„LOG_ERRŽLogtheerror.*‹BRA„INT_EXITAndexitfromtheinterrupt.ŠENDI ŠSF…BRK_FLAG(A5)2ŠBRA„INT_EXITŽIfnothingisset,thiswasprobably&*¦endofabreaksignal,sowe'llexit*¦fromthisinterrupt. PAGE BPROCBRKƒJSR„TERM_BREAK‰Processingthebreakisdevice-independent.-ŠST…BRK_FLAG(A5)‡Setthereceivedbreakflag.7*‰BRA‡INT_EXITˆFallthroughtoexitfromtheinterrupt. SPC 5O*********************************************************************************‰INTERRUPTEXITROUTINE*/*‰AllinterruptsreturntoCMRviathisroutine*O******************************************************************************* INT_EXIT:POP.L‚D1‘RestoreD1,7ŠMOVEQ‚#1,D0ŽsetcarrybittotellCMR'wehandledit,' ŠSUBQƒ#2,D0Ž*ŠRTS—andreturn. SPC 10O********************************************************************************"*ˆENDOFINTERRUPTSERVICEROUTINE*O*******************************************************************************ŠPAGEO*********************************************************************************!*ROUTINES„CALLED„BY**–TERMLIB**O*******************************************************************************‰PAGEL******************************************************************************ˆTRANSMITTHECHARACTER*C*ˆThisisadevicedependentroutinewhoseoffsetmustbeinstalledA*ˆatthebeginningofthedriver.‚ThefunctionofthisroutineisC*ˆwritethecharactercontainedinD0tothetransmitdataregister*ˆofthedevice.*;*ˆWearerunninginbackgroundwhenthisroutineiscalled.*-*ˆEntry:A1=addressofoursideofthechip*A5=addressofCCB*D0.B=charactertotransmit**Interruptlevelonentryis0**ˆExit:‚RTStocaller*0*ˆThisroutinemustpreserveallregistersused.0*ˆTheinterruptleveluponexitmustbethesame*ˆasitwasuponentry.*J************************************************************************** PUT_CHAR:=ŠMOVE.BD0,MFP_UDR(A1)‰Loadthedataregisterwithcharacter.ŠRTSŠPAGEM******************************************************************************$*ˆCHECKTHEDEVICE'STRANSMITBUFFER*C*ˆThisisadevicedependentroutinewhoseoffsetmustbeinstalledD*ˆatthebeginningofthedriver.ThefunctionofthisroutineistoF*ˆcheckthatthetransmitbufferisemptybeforeallowinganytransmit*ˆactivity.*;*ˆWearerunninginbackgroundwhenthisroutineiscalled.*-*ˆEntry:A1=addressofoursideofthechip*A5=addressofCCB**InterruptM levelonentryis0*/*ˆExit:‚RTStocallerwithConditioncodesset:"*=transmitbuffernotempty*=transmitbufferempty*0*ˆThisroutinemustpreserveallregistersused.0*ˆTheinterruptleveluponexitmustbethesame*ˆasitwasuponentry.*M***************************************************************************** CK_TBE:>ŠBTST.B#BE,MFP_TSR(A1)ˆTesttransmitbufferemptybitinTSR./ŠBNE.S‚CK_END‘We'rereadytotransmitifempty.=ŠBTST.B#END,MFP_TSR(A1)‡Ifnotempty,checkendoftransmit. CK_END„RTS ŠPAGEH************************************************************************* *ˆDEVICEDEPENDENTRESETROUTINE*C*ˆThisisadevicedependentroutinewhoseoffsetmustbeinstalledD*ˆatthebeginningofthedriver.ThefunctionofthisroutineistoC*ˆperformaminimumresetofthedevice.FortheMK68901thismeans6*ˆclearinganyerrorstatusandenablingthereceiver.*;*ˆWearerunninginbackgroundwhenthisroutineiscalled.**ˆEntry:A5=addressofCCB**Interruptlevelonentryis0**ˆExit:‚RTStocaller*0*ˆThisroutinemustpreserveallregistersused.0*ˆTheinterruptleveluponexitmustbethesame*ˆasitwasuponentry.*E********************************************************************* DDP_RESET: 6ŠMOVEM.LD0/A1,-(A7)‹Saveusedregistersonthestack..ŠMOVE.LCCBCHB(A5),A1ŠA1<--addrofourport.1ŠMOVE.B#1,MFP_RSR(A1)‰Clearanyreceiverstatus.@ŠMOVE.B#$05,MFP_TSR(A1)‡Clearanytransmitterstatusw/TXoff./ŠMOVEM.L(A7)+,D0/A1‹Restoreworkingregisters.ŠRTSŠPAGEJ***************************************************************************@*ˆSUBROUTINETOSETUPTHEDEVICEACCORDINGTOTHECONFIGURATION*C*ˆThisisadevicedependentroutinewhoseoffsetmustbeinstalledD*ˆatthebeginningofthedriver.ThefunctionofthisroutineistoE*ˆsetupthedeviceaccordingtotheworkingconfigurationintheCCB3*ˆandsomeconfiguration-relatedfieldsintheCCB.*;*ˆWearerunninginbackgroundwhenthisroutineiscalled.**ˆEntry:A5=addressofCCB**Interruptlevelonentryis0**ˆExit:‚RTStocaller*0*ˆThisroutinemustpreserveallregistersused.0*ˆTheinterruptleveluponexitmustbethesame*ˆasitwasuponentry.*J************************************************************************** SETUP:/ŠMOVEM.LD0/A0/A1,-(A7)ˆGetsomeworkingspace.3ŠLEA…CONFIG(A5),A0‰A0<--addrofCCB‚configuration/ŠMOVE.L‚CCBCHB(A5),A1‰A1<--addrofourdevice*,*ˆInsureourportisunreadywhilewesetup.*8ŠCMP.Bƒ#120,DRV_FLAG(A5)„Findoutwhatboardwe'reon...'ŠIF†THENŒIfthisistheMVME120...4ŠOR.B„#UNR_120,MCR‰ModifyCTS*usingMCRonthe120.ŠELSE™ThisistheMVME128...4ŠOR.W„#UNR_128,MCR‰ModifyCTS*usingMCRonthe128.ŠENDI$ŠCLR.BƒMFP_RSR(A1)‹Disablereceiver.'ŠCLR.BƒMFP_TSR(A1)‹Disabletransmitter.2ŠCLR.BƒMFP_TCDCR(A1)‰Stoptransmit/receiverclock.*!*ˆClearthebreakflagintheCCB*ŠCLR.B‚BRK_FLAG(A5) PAGE**ˆSelectBaudRate*&ŠMOVEQ.Lƒ#0,D0Clearworkingregister.2ŠMOVE.B„IOSBRT(A0),D0‡GetVERSAdosbaudratecode.+ŠLSL.L…#1,D0Doubleittouseinourtable. 8ŠCMP.B…#120,DRV_FLAG(A5)ƒFindoutwhatboardwe'reon...'ŠIFˆTHEN‹IfthisistheMVME120...>ŠBTST.B„#SW2,MFP_GPIP(A1)ƒTestfortheVME120processorspeed.ŠELSE5ŠBTST.B„#SW6,MCRŒTestfortheVME128processorspeed.ŠENDI ŠIFTHEN8‹MOVE.WBAUD10(PC,D0.W),D0ƒWehavethe10Mhzprocessor.ŠELSE:‹MOVE.WBAUD12(PC,D0.W),D0ƒWehavethe12.5Mhzprocessor.ŠENDI <ŠMOVE.B„D0,MFP_TCDR(A1)…SetcountviaTimerCdataregister.'ŠROR.W…#8,D0GettheprescaleintoLSB.>ŠMOVE.B„D0,MFP_TCDCR(A1)„SetprescaleviaTimerCcontrolreg. ŠBRA.S…PASSTBLŠPAGEO********************************************************************************0*ˆTABLEFORTRANSLATINGVERSADOSBAUDRATECODES*@*ˆThereare2baudratetablesdepenN dentontheprocessorspeed;&*ˆonefor10Mhzandonefor12.5Mhz.*"*ˆThetablesaresetuplikethis:=*Œ1stentryistheprescalevaluetobewrittentoMFP_TCDCR.3*Œ2ndentryisthecounttobewrittentoMFP_TCDR.;*ˆBothofthesevaluesaredefinedintheuser'smanualfor#*ˆtheVME120andtheVME128boards.*<*ˆNotalloftheVERSAdosbaudratecodesaresupported.‚The@*ˆsupportedbaudratesaredefinedinamodulecalledTCHTYPE.AG;*ˆwhichislinkedintothegenericterminaldriverTERMLIB.?*ˆTERMLIBshouldreturnaconfigurationerrorisanunsupported>*ˆbaudrateisselected.‚Unsupportedbaudrateshaveadefault>*ˆvalueof9600baudinthistable,justincaseoneshouldbe*ˆselected.*O******************************************************************************* 5BAUD10ƒDC.B‚$10,250…****notsupported-default9600/‰DC.B‚$10,275…****notsupported-default9600‰DC.B‚$20,71Ž1102‰DC.B‚$10,2134.5‚****notsupported-default96000‰DC.B‚$10,2150„****notsupported-default9600‰DC.B‚$10,65Ž300‰DC.B‚$10,33Ž600‰DC.B‚$10,16Ž12001‰DC.B‚$10,21800ƒ****notsupported-default96001‰DC.B‚$10,22000ƒ****notsupported-default9600‰DC.B‚$10,824001‰DC.B‚$10,23600ƒ****notsupported-default9600‰DC.B‚$10,448001‰DC.B‚$10,27200ƒ****notsupported-default9600‰DC.B‚$10,296002‰DC.B‚$10,219200‚****notsupported-default9600 5BAUD12ƒDC.B‚$20,150…****notsupported-default9600/‰DC.B‚$20,175…****notsupported-default9600‰DC.B‚$30,55Ž1102‰DC.B‚$20,1134.5‚****notsupported-default96000‰DC.B‚$20,1150„****notsupported-default9600‰DC.B‚$10,81Ž300‰DC.B‚$10,41Ž600‰DC.B‚$10,20Ž12001‰DC.B‚$20,11800ƒ****notsupported-default96001‰DC.B‚$20,12000ƒ****notsupported-default9600‰DC.B‚$10,10Ž24001‰DC.B‚$20,13600ƒ****notsupported-default9600‰DC.B‚$10,548001‰DC.B‚$20,17200ƒ****notsupported-default9600‰DC.B‚$20,196002‰DC.B‚$20,119200‚****notsupported-default9600PASSTBL‚DS.W‚0‰PAGE* *ˆSetControlRegister(MFP_UCR) *Œstartwith1/16clockrate[7]*ŠPUT_BYTECLOCK16,D0 * Word length control [6:5]:ŠBTSTW#IOABITS,IOSATW(A0)…Addinbitspercharacterinfo. ŠIF„THEN ‹OR.B#BIT7,D07bits/character.ŠELSE ‹OR.B#BIT8,D08bits/character.ŠENDI * Stop Bit Length [4:3]:ŠBTSTW#IOASTPB,IOSATW(A0)…Addinthenumberofstopbits. ŠIF„THEN‹OR.B#SB1,D0‘1stopbit.ŠELSE‹OR.B#SB2,D0‘2stopbits.ŠENDI * Parity Mode [2:1]3ŠBTSTW#IOAUSEP,IOSATW(A0)…Ifwe'reusingparity... ŠIF„THEN(‹OR.B#PARENAB,D0Setenableparitybit.0‹BTSTW#IOAPRTY,IOSATW(A0)„Ifitsevenparity... ‹IF„THEN&ŒOR.B#PAREVEN,D0ŒSetevenparitybit.‹ENDIŠENDI+ŠMOVE.BD0,MFP_UCR(A1)ŠTellittothechip. PAGE*!*ˆSetuptheinterruptregisters.* /* Unmask those interrupts we'd like to receive.ŠINHIBIT7ŠMOVE.BMFP_IMRA(A1),D0ˆReadinterruptmaskregisterA./ŠOR.Bƒ#UNMASK,D0UnmasktheRCA/TBEinterrupts.&ŠMOVE.BD0,MFP_IMRA(A1)ˆWriteitback. 2* Enable those interrupts we'd like to know about.9ŠMOVE.BMFP_IERA(A1),D0ˆReadinterruptenableregisterB.1ŠOR.Bƒ#ENABLE,D0Enablethoseinterruptsweneed.&ŠMOVE.BD0,MFP_IERA(A1)ˆWriteitback. 9ŠMOVE.BMFP_IERB(A1),D0ˆReadinterruptenableregisterB.!ŠBSETƒ#SW2,D0EnableGPIPline0.&ŠMOVE.BD0,MFP_IERB(A1)ˆWriteitback. **ˆNowsetourportasready.*8ŠCMP.Bƒ#120,DRV_FLAG(A5)„Findoutwhatboardwe'reon...'ŠIF†THENŒIfthisistheMVME120...5ŠAND.Bƒ#RDY_120,MCR‰ModifyCTS*usingMCRonthe120.ŠELSE™ThisistheMVME128...5ŠAND.Wƒ#RDY_128,MCR‰ModifyCTS*usingMCRonthe128.ŠENDI+ŠMOVE.B#1,MFP_RSR(A1)ˆEnablethereceiver.0ŠMOVE.B#$05,MFP_TSR(A1)†Enablethetransmitter.**ˆRestoreregistersandreturn.*ŠUNMASKŠMOVEM.Lƒ(A7)+,D0/A0/A1ŠRTSŠPAGEO*********************************************************************************‰RESETTHECLOCK*C*‰ThisisadevicedependentroutinewhoseoffsetmustbeinstN alledD*‰atthebeginningofthedriver.Thefunctionofthisroutineisto3*‰changetheclockspeedbacktoitsdefaultvalue.*;*‰Wearerunninginbackgroundwhenthisroutineiscalled.*"*‰Entry:A1=addressofourport.*A5=addressofourCCB.**Interruptlevelonentryis0**‰Exit:‚RTStocaller*0*‰Thisroutinemustpreserveallregistersused.0*‰Theinterruptleveluponexitmustbethesame*‰asitwasuponentry.*O******************************************************************************* CLOCK_RESET:*J*ƒThisfunctionalityisnotsupportedbytheMK68901ontheVME120/VME128.*ŠRTSŠPAGEJ****************************************************************************‰GETDEVICESTATUSBYTE*C*‰ThisisadevicedependentroutinewhoseoffsetmustbeinstalledD*‰atthebeginningofthedriver.ThefunctionofthisroutineistoA*‰preparestheDEVICESTATUSbytewhichcontainstheconditionof7*‰theDTR*line(whichindicatesdeviceready/unready).*8*‰Note:‚Thisroutinedoesnotsetthebreakindicatorin*thedevicestatusbyte.*;*‰Wearerunninginbackgroundwhenthisroutineiscalled.**‰Entry:A5=addressofCCB**Interruptlevelonentryis0*!*‰Exit:‚D0.B=DeviceStatusbyte*RTStocaller.*0*‰Thisroutinemustpreserveallregistersused.0*‰Theinterruptleveluponexitmustbethesame*‰asitwasuponentry.*J************************************************************************** GET_STAT:,ŠMOVEM.LD1/A1,-(A7)‹Saveworkingregisters.'ŠCLR.LƒD0”Devicestatustobereturned..ŠMOVE.L‚CCBCHB(A5),A1‰A1<--addrofourport.<ŠMOVE.B‚MFP_GPIP(A1),D1‡D1<--statusofVME120inputlines.#ŠBTST„#DTR,D1TesttheDTR*line...1ŠIF†THENIfDTR*ishigh,deviceisunready.0‹BSET#XDSNRB,D0ŽSetunreadybitinstatusbyte.ŠENDI/ŠMOVEM.L(A7)+,D1/A1‹Restoreworkingregisters.ŠRTSŠPAGEM*******************************************************************************ˆSTOPTHETRANSMITTINGDEVICE*C*ˆThisisadevicedependentroutinewhoseoffsetmustbeinstalledD*ˆatthebeginningofthedriver.ThefunctionofthisroutineistoA*ˆchangeahardwareoutputlinetomakeourdevicelook'unready''*ˆsothetransmittingdevicewillstop.*;*ˆWearerunninginbackgroundwhenthisroutineiscalled.*"*ˆEntry:A1=addressofourport.*A5=addressoftheCCB.*5*InterruptlevelonentryisINHIBITEDatourlevel.**ˆExit:‚RTStocaller*0*ˆThisroutinemustpreserveallregistersused.0*ˆTheinterruptleveluponexitmustbethesame*ˆasitwasuponentry.*K*************************************************************************** DDP_STOP:8ŠCMP.Bƒ#120,DRV_FLAG(A5)„Findoutwhatboardwe'reon...'ŠIF†THENŒIfthisistheMVME120...4ŠOR.B„#UNR_120,MCR‰ModifyCTS*usingMCRonthe120.ŠELSE™ThisistheMVME128...4ŠOR.W„#UNR_128,MCR‰ModifyCTS*usingMCRonthe128.ŠENDIŠRTSŠPAGEK****************************************************************************$*ˆDEVICEDEPENDENTUNSTOPTHEDEVICE*C*ˆThisisadevicedependentroutinewhoseoffsetmustbeinstalledD*ˆatthebeginningofthedriver.ThefunctionofthisroutineistoC*ˆunstopthetransmittingdevicebychangingahardwareoutputline"*ˆtomakeourdevicelook'ready'.*;*ˆWearerunninginbackgroundwhenthisroutineiscalled.*"*ˆEntry:A1=addressofourport.*A5=addressoftheCCB*5*InterruptlevelonentryisINHIBITEDatourlevel.**ˆExit:‚RTStocaller.*0*ˆThisroutinemustpreserveallregistersused.0*ˆTheinterruptleveluponexitmustbethesame*ˆasitwasuponentry.*J************************************************************************** DDP_UNSTOP:8ŠCMP.Bƒ#120,DRV_FLAG(A5)„Findoutwhatboardwe'reon...'ŠIF†THENŒIfthisistheMVME120...5ŠAND.Bƒ#RDY_120,MCR‰ModifyCTS*usingMCRonthe120.ŠELSE™ThisistheMVME128...5ŠAND.Wƒ#RDY_O 128,MCR‰ModifyCTS*usingMCRonthe128.ŠENDIŠRTSŠPAGEK****************************************************************************&*ˆDEVICEDEPENDENTBEGINBREAKROUTINE*C*ˆThisisadevicedependentroutinewhoseoffsetmustbeinstalledD*ˆatthebeginningofthedriver.Thefunctionofthisroutineisto@*ˆgiveacommandtostartsendingbreakconditiontoourdevice.*;*ˆWearerunninginbackgroundwhenthisroutineiscalled.*"*ˆEntry:‚A1=addressofourport.*A5=addressoftheCCB*5*InterruptlevelonentryisINHIBITEDatourlevel.**ˆExit:ƒRTStocaller*0*ˆThisroutinemustpreserveallregistersused.0*ˆTheinterruptleveluponexitmustbethesame*ˆasitwasuponentry.*E********************************************************************* DDP_BEG_BREAK:?ŠMOVE.B#1<ŠMOVE.B#0<*‰fromwithinthebackground.‚Soheinvokedthisroutinetodo *‰itforhim.*?*‰Inaddition,theseotherdevice-dependentthingsMUSTbedone>*‰beforewecanhandlecommands.‚Theyprobablycouldhavebeen?*‰doneinINITatthestartofthedriverbutarehandledhere.*5*‰1.‚PutthestartaddressofthedriverintotheCCB*variableDRV_ADDR.>*‰2.‚Setupthedevice-dependentBABsusingthemacroSET_BAB.;*‰3.‚PuttheaddressoftheA-sideofadualchanneldevice6*intotheCCBvariableADRSIDEA.‚Ifnotdualchannel,**puttheaddressofPort1intoADRSIDEA.**‰Entry:A5=addressofCCB.*6*‰Calls:RESETinthegenericterminaldriverTERMLIB.*DDP_RESETinthisdriver.6*MARK_DOWNinthegenericterminaldriveriffailure.*O******************************************************************************* DO_INIT:**‚Inhibitinterrupts*‰PUSH†SR‰INHIBIT*)*‚GetaddressofstartofdriverintoCCB*ŠLEA‡MFPDRV(PC),A4ŠMOVE.L„A4,DRV_ADDR(A5)*J*‚SetuptheaddressoftheAsideoftheSerialportwithdeviceaddress.*@ŠMOVE.LCCBCHB(A5),ADRSIDEA(A5)‚MovedeviceaddressintoA-side. ŠJSR„RESETŽReseteverything.ŠBSR.L‚DDP_RESETŠPOP‡SR ŠRTS 7FAIL†JSR„MARK_DOWNŠMarkthechanneldownusingTERMLIB.ŠPOP‡SRŠRTSŠPAGE*********************** *‚PATCHSPACE***********************ŠDS.Wƒ30ŠEND O éééééé=/*=/*†MPCCDRV.AF=/*G=/* Chain file to assemble R68560 serial port driver for the local port*=/* on the VME050 system controller board.=/*:=/* If no output argument is specified for the listing the)=/* chain file will default to MPCCDRV.LS=/*=/IFC \1ƒ=ARGMPCCDRV.LS=/ENDIF=/*$=ASM MPCCDRV.SA,MPCCDRV.RO,\1;RZ=140=/*{ Included files are:=/*ƒ9995.&.STR.EQ=/*ƒ9995.&.TCB.EQ=/*ƒ9995.&.CCB.EQ=/*ƒ9995.&.IOE.EQ=/*ƒ9995.&.NIO.EQ=/*ƒ9995.&.LV5.EQ=/*ƒ9995.&.BAB.EQ=/*ƒ9995.&.UTILITY.MC=/*ƒ9995.&.TERMCCB.EQ=/*ƒ9995.&.TERMINAL.EQ=/*}=/*=ENDééééé îé