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Text File | 1998-10-30 | 9.9 KB | 331 lines

.mcall .modul .modul hd,versio=1,commen=<Russian Hypothetical Disk Handler>,audit=yes ;++ ; ; Ersatz-11 Hypothetical Disk device handler for RT-11 V5.X. ; ; The HD: device in Ersatz-11 is included for compatibility with boot images ; intended for the Russian PDP-11/03 emulator (I would credit the author but ; the read-me file seems to be in Russian, and is mostly non-ASCII). I have ; extended the device to include interrupts and 18-bit addressing (for all I ; know the HD_SYS.EXE driver does this too, but if so they aren't used by the ; HD.SYS driver supplied with the emulator which is what I looked at). ; ; For the record, this driver is nothing to do with the code in the Russian ; HD.SYS handler (it actually looks more like the RK.SYS code since that's ; beautifully documented as an example handler in the V4 Software Support ; Manual). Also, it uses the interrupts, and 18-bit addressing (when ; assembled with MMG$T set), and is thus incompatible with the Russian ; PDP-11/03 emulator. However a new driver was necessary to support floppies ; (w/o stalling the system), and to work with XM. This driver is intended to ; be used as a stopgap until MSCP emulation is added to Ersatz-11, to handle ; devices of arbitrary sizes. ; ; This driver is for RT-11 V5.X, but was written using the V4.X SSM, so there ; are a few things that RK.MAC has that I don't know what they're for. I may ; get around to adding V4.X conditionals, although things would be a little ; ugly under V4.X since it didn't have the VARSZ$ bit, so presumably you have ; to patch DUP to make INIT bother to ask the driver for the size (with ; special function #373). ; ; By John Wilson. ; ; 16-Mar-1995 JMBW Created. ; 31-Oct-1998 JMBW Reduced unit number mask to 3 bits for TSX. ; ;-- .mcall .drdef,.assume ; .readw= emt!375 .writw= emt!375 ; .if eq mmg$t .drdef hd,377,filst$!spfun$!varsz$,128.,177110,234,dma=no .iff .drdef hd,377,filst$!spfun$!varsz$,128.,177110,234,dma=yes .endc ; ; These are new since V4, no idea what they are: .drptr .drest class=dvc.dk ; ; Device registers: ; hdcs= hd$csr ;777110 control/status register hdbc= hdcs+2 ;777112 byte count register hdblk= hdcs+4 ;777114 starting block register hdba= hdcs+6 ;777116 bus address register hdatn= hdcs+10 ;777120 drive attn register (disk change) hdst= hdcs+12 ;777122 ctrlr error/drive status register hdblke= hdcs+14 ;777124 starting block register extension hdbae= hdcs+16 ;777126 bus address extension ; hdcnt= 8. ;number of error retries hdnreg= 8. ;number of regs to read for error log ; ; Bits in HDCS: ; cserr= 100000 ;error csunit= 17000 ;unit csrdy= 200 ;ready csie= 100 ;interrupt enable (not on original HD_SYS.EXE) csbae= 60 ;bus address extension (" " " ") csfun= 16 ;function code csgo= 1 ;go bit ; ; Function codes in CSFUN: ; fnack= 0*2 ;medium acknowledge fnread= 1*2 ;read block(s) fnwrit= 2*2 ;write block(s) fngtsz= 3*2 ;get volume size ; .SBTTL installation code ; ; This is new since V4... ; .drins hd ;used to just be .=200 nop ;same for system and non-system handler nop ;RK.SYS had this NOP too clc ;what, me worry? rts pc ; .sbttl SET options ; .drset csr,160000,o.csr,oct .drset vector,500,o.vec,oct .drset retry,127.,o.rtry,num .iif ne erl$g, .drset succes,-1,o.succ,no ; btcsr= <hdend-hdstrt>+<botcsr-hdboot>+1000 ;loc in HD.SYS of BOTCSR o.csr: ; SET HD: CSR=oooooo cmp r0,r3 ;in I/O page? blo o.bad ;no, invalid mov r0,inscsr ;save mov r0,discsr mov pc,r1 ;point at BAREA+4 with r1 add #barea-.+4,r1 mov pc,r2 ;and .+2+1000 with r2 add #1000-.,r2 mov r2,(r1) ;fill in BUF field mov #btcsr/1000,-(r1) ;block containing BOTCSR tst -(r1) ;skip function,,channel mov r0,r3 ;save their value mov r1,r0 ;point with R0 .readw ;read the block bcs o.bad ;failed mov r3,<btcsr&777>(r2) ;fill in CSR addr in boot driver mov r1,r0 ;point at EMT area again incb 1(r0) ;change function to .WRITW .writw ;write it back bcs o.bad ;it's not our day mov r1,r0 ;point yet again decb 1(r0) ;back to .READW again mov #1,2(r0) ;change to block 1 .readw ;restore bcs o.bad mov r3,hdcsr ;finally save it o.good: tst (pc)+ ;skip the SEC, C=0 o.bad: sec ;unhappy rts pc o.vec: ; SET HD: VECTOR=ooo cmp r0,r3 ;<=500 right? bhis o.bad ;no, idiot bit #3,r0 ;mult of 4 right? bne o.bad ;doofus mov r0,hdstrt ;groovy, save it br o.good o.rtry: ; SET HD: RETRY=ddd cmp r0,r3 ;in range? bhi o.bad ;no mov r0,dretry ;save it bne o.good ;it's non-zero right? br o.bad ;whoops .if ne erl$g o.succ: ; SET HD: [NO]SUCCES mov #0,r3 ;set or clear mov r3,scsflg ;save flag br o.good ;can't screw this up .endc ; barea: .byte 17,10 ;.READW, channel 17 .blkw ;block # .blkw ;buf addr .word 256. ;the whole block .word 0 ;no crtn .assume . le 1000,<;SET area overflow> ; .sbttl driver entry ; .drbeg hd mov (pc)+,(pc)+ ;init retry counter dretry: .word hdcnt .assume . le hdstrt+1000,<;SET object not in block 1> retry: .word ;retry count ; we won't bother to pre-compute the disk location for retries because there's ; no calculation to do. again: mov hdcqe,r5 ;get curr queue entry mov q$unit-1(r5),r3 ;unit # in MSB bic #^C<7*400>,r3 ;isolate 3-bit unit number in MSB asl r3 ;should start at bit 9 bis #csie!fnread!csgo,r3 ;assume it's a read mov (pc)+,r4 ;pick up CSR addr hdcsr: .word hdcs .assume . le hdstrt+1000,<;SET object not in block 1> mov (r5),hdblk-hdcs(r4) ;set block number clr hdblke-hdcs(r4) ;clear out block extension (32MB limit) cmp (r5)+,(r5)+ ;skip to Q.BUFF for $MPPHY .if ne mmg$t ; XM, translate Q.BUFF virtual address into physical 18-bit address call @$mpptr ;call $MPPHY mov (sp)+,hdba-hdcs(r4) ;get low 16 bits of real addr bis (sp)+,r3 ;OR high 2 bits into CSR value (bits 5:4) .iff ; SJ or FB, addresses are all real and bits 17:16=00 mov (r5)+,hdba-hdcs(r4) ;copy address .endc movb q$func-q$wcnt(r5),r2 ;get function code bmi 20$ ;.SPFUN, skip mov (r5)+,r0 ;get word count beq 30$ ;0, seek (no op with us) bpl 10$ ;read, skip neg r0 ;take absolute value add #fnwrit-fnread,r3 ;change function code to write 10$: asl r0 ;WC*2=byte count mov r0,hdbc-hdcs(r4) ;write it out mov r3,(r4) ;start transfer rts pc ;back on interrupt 20$: ; .SPFUN call cmpb r2,#373 ;cmd = get volume size? bne 30$ ;skip if not mov #1,r0 ;word count=1 word add #fngtsz-fnread,r3 ;change function code to "get size" br 10$ ;go do it 30$: ; seek, no op br hdexit ;there won't be any interrupt ; .if ne erl$g scsflg: .word 0 ;success flag .assume . le hdstrt+1000,<;SET object not in block 1> .endc ; .sbttl interrupt entry point ; .drast hd,5 ;say hi to the scheduler, switch to prio 5 mov hdcsr,r5 ;get CSR addr tst retry ;are we in the middle of a retry? bpl normal ;no tst (r5) ;yes, did reset work? bmi normal ;no, error .fork hdfblk ;yes, drop to fork level for the retry hdretr: clrb retry+1 ;clear the "reset in progress" flag br again ;retry the request ; normal: tst (r5) ;any error? bpl done ;no .fork hdfblk ;drop to fork level to handle the error .if ne erl$g mov pc,r5 ;point at HDRBUF with r5 add #hdrbuf-.,r5 mov r5,r2 ;save a copy mov hdcsr,r3 ;get CSR mov #hdnreg,r4 ;# regs to read hdrreg: mov (r3)+,(r5)+ ;get a word dec r4 ;might as well be good and not use SOB bne rkrreg ;in case emulating 11/04 etc. mov dretry,r3 ;get max # retry counts swab r3 ;in left half add #hdnreg,r3 ;# regs in right half mov hdcqe,r5 ;get curr queue element movb retry,r4 ;get actual # retries to go -1 dec r4 call @$elptr ;log it mov hdcsr,r5 ;restore CSR ptr .endc hderr: decb retry ;give up yet? beq herror ;yep bis #100000,retry ;set reset-in-progress bit movb #csie!fnack!csgo,(r5) ;reset drive (may not do anything) rts pc ; herror: mov hdcqe,r5 ;get qel bis #hderr$,@-(r5) ;set hard error flag in CSW ; log error if enabled .if ne erl$g br hdexit done: .fork hdfblk ;continue at fork level tst scsflg bne hdexit mov (pc)+,r4 ;pick up our device code .byte 377,hd$cod ;(defined in .DRDEF at top) mov hdcqe,r5 ;get qel call @$elptr ;log it .iff ; eq erl$g done: .endc hdexit: clr retry ;not in error recovery .drfin hd ;dive into RMON hdfblk: .word 0,0,0,0 ;.FORK block used by error log code .if ne erl$g hdrbuf: .blkw hdnreg .endc ; .sbttl bootstrap driver ;+ ; ; This stuff is scattered around the boot block. For various reasons the boot ; code is entered by a NOP, two BRs and a JMP. Once we get there we just load ; in the BSTRAP secondary loader using a simple polled I/O read routine, which ; BSTRAP then calls to look at the directory and load the monitor and the ; minimum device handlers (TT: and the system device). Then it hooks up the ; real system device handler and we're on our way. ; ;- .drbot hd,boot1,read .= hdboot+40 boot1: jmp @#boot-hdboot ;hop, skip, now jump, this is so dumb .= hdboot+210 ;+ ; ; Bootstrap read routine. ; ; r0 starting block # ; r1 word count ; r2 bus address of buf ; ;- read: mov botcsr,r3 ;get CSR addr mov r0,hdblk-hdcs(r3) ;set block address clr hdblke-hdcs(r3) ;(clear high word) asl r1 ;*2 mov r1,hdbc-hdcs(r3) ;set byte count mov r2,hdba-hdcs(r3) ;set bus addr movb #fnread!csgo,(r3) ;read data, leave unit bits alone 10$: tstb (r3) ;done? bpl 10$ ;spin until so tst (r3) ;error? (C=0) bmi 20$ rts pc 20$: jmp bioerr ;our READ routine is too short! can't reach ; .= hdboot+574 boot: ; load secondary bootstrap from blocks 2-5 of the volume, at 001000 mov #10000,sp ;set up stack mov @(pc)+,-(sp) ;get boot unit # from CSR botcsr: .word hdcs ;preassembled CSR addr asr (sp) ;right a bit swab (sp) ;right 8 more bits bic #^C<csunit/1000>,(sp) ;isolate unit # mov #2,r0 ;BSTRAP starts at block 2 mov #<4*400>,r1 ;4 blocks mov #1000,r2 ;load at 001000 call read ;go do it (N.B. relative addressing) ; set up BSTRAP entry conditions mov #read-hdboot,@#b$read ;set pointer to standalone read routine mov #b$dnam,@#b$devn ;set system device name mov (sp)+,@#b$devu ;set boot unit number jmp @#b$boot ;go for it ; .drend hd ;that's it, give us BIOERR ; .end