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Text File | 1993-09-07 | 21.2 KB | 703 lines

; virtual.s ; Part of the !Virtual distribution ; (c) bdb/nas/fo, 1992-3 ; Assemble with: ;aasm s.Virtual Virtual -M -Q GBLL DEBUG DEBUG SETL {FALSE} GBLL SWIS SWIS SETL {TRUE} GBLL OLD_VERSION OLD_VERSION SETL {FALSE} R0 RN 0 R1 RN 1 R2 RN 2 R3 RN 3 R4 RN 4 R5 RN 5 R6 RN 6 R7 RN 7 R8 RN 8 R9 RN 9 SL RN 10 FP RN 11 IP RN 12 SP RN 13 LR RN 14 PC RN 15 a1 RN 0 a2 RN 1 a3 RN 2 a4 RN 3 v1 RN 4 v2 RN 5 v3 RN 6 v4 RN 7 v5 RN 8 v6 RN 9 fp RN 10 ip RN 11 sp RN 12 lr RN 14 pc RN 15 N_bit * 1 :SHL: 31 Z_bit * 1 :SHL: 30 C_bit * 1 :SHL: 29 V_bit * 1 :SHL: 28 I_bit * 1 :SHL: 27 F_bit * 1 :SHL: 26 USR_mode * 0 FIQ_mode * 1 IRQ_mode * 2 SVC_mode * 3 GET Hdr.Swis GET Hdr.Module SUBT S.Virtual - virtual memory thing. swibase * &47900 ; Acorn-allocated :-) MACRO CLRV $cc CMP$cc pc,#0 MEND MACRO NOP ANDEQ R0,R0,R0 MEND ; per task workspace ^ 0,ip regs # 64 stacktop # 4 AREA |!!!Module$$Header|,CODE,READONLY base & start-base & init-base & finish-base & service-base & title-base & help-base & cmdtab-base [ SWIS & swibase & swihandler-base & switable-base & 0 ] title = "Virtual",0 help = "Virtual Memory",9,"0.37 (07 Sep 1993) by BDB/NAS/FO",0 cmdtab = "Virtual",0 ALIGN & Virtual-base = 0,0,20,0 & Virtualsynx-base & Virtualhelp-base & 0 Virtualhelp = "The *Virtual command allows a task to be run with virtual memory.",13,10 Virtualsynx = "Syntax: *Virtual [<command>] [-wimpslot <n>K] [-discslot <n>M] [-name <taskname>] [-nice <n>] [-ctrl] [-display] [-quit]",13,10 = " <command> is the command to be executed",13,10 = " -wimpslot sets the physical memory to be allocated; the virtual memory is set by the -discslot parameter, default 24M",13,10 = " -nice sets the task priority: 9 low priority, 0 high priority, default 4",13,10 = " -name sets the task name",13,10 = " -ctrl allows control characters through",13,10 = " -display opens the task window immediately, rather than waiting for a character to be printed",13,10 = " -quit makes the task quit after the command even if the task window has been opened",13,10 = "Note that fields must be in "" "" if they comprise more than one word", 0 [ SWIS ALIGN switable = "Virtual",0 = "TaskInfo",0 = "Physical",0 = 0 ] ;SL env WriteS ;FP instantiation number ;IP currently preferred instantiation ;SP SVC mode stack ;Preserve R7-FP,SP IMPORT |__RelocCode| IMPORT Cinit init STMDB SP!,{SL,FP,LR} BL |__RelocCode| MOV a1,IP MOV sp,SP SUB SP,SP,#1024 MOV fp,#0 BL Cinit CLRV TEQ R0,#0 TEQNEP PC,#V_bit+SVC_mode ADD SP,SP,#1024 LDMIA SP!,{SL,FP,PC} ;R1 service number, may zero ;IP currently preferred instantiation ;SP a stack, SVC or IRQ ;Preserve R0,R2-R8 unless returning values ;May corrupt IP service TEQ R1,#&11 ;Service_Memory MOVNE PC,LR ADR IP,base TEQ R2,IP MOVEQ R1,#0 ;claim MOV PC,LR ;R0 command tail ;R1 command count ;IP currently preferred instantiation ;SP SVC mode stack ;Preserve R7-FP Virtual STMFD SP!,{LR} LDR IP,[IP] MOV R2,R0 ;parameters MOV R0,#2 ;Enter ADR R1,title SWI XOS_Module LDMFD SP!,{PC} ;SL fatal flag ;FP instantiation number ;IP currently preferred instantiation ;SP SVC mode stack ;Preserve R7-FP,SP IMPORT Cfinish finish STMDB SP!,{SL,FP,LR} MOV a1,IP MOV sp,SP SUB SP,SP,#1024 MOV fp,#0 BL Cfinish CLRV TEQ R0,#0 TEQNEP PC,#V_bit+SVC_mode ADD SP,SP,#1024 LDMIA SP!,{SL,FP,PC} [ SWIS ;(R9 SWI chunk *4) ;(SL routine addr) ;FP SWI number mod 64 ;IP private word ;SP super stack (R9 LR swi-no SL FP IP) ;LR flags of caller with VC ;(R9,)SL-IP may be corrupted, return with MOVS ;R0-R8 as caller ;IRQs (NOT) disabled on entry, may enable them swihandler LDR IP,[IP] STMFD SP!,{R0-R3,LR} CMP FP,#(endjumptable-jumptable)/4 ADDCC PC,PC,FP,LSL#2 B unknownswierror jumptable B TaskInfo B DoPhysical endjumptable unknownswierror LDMFD SP!,{R0-R3,LR} ADR R0,unknownswimsg ORRS PC,LR,#V_bit unknownswimsg & &1E6 = "Unknown Virtual SWI",0 ALIGN ; R0 task id ; R1 Virtual address ; R2 buffer ; R3 len ; CDoPhysical passed private workspace as 5th arg IMPORT CDoPhysical DoPhysical SUB SP,SP,#1024 STR IP,[SP,#1020] ;caution, IP=sp ADD sp,SP,#1020 MOV fp,#0 BL CDoPhysical ADD SP,SP,#1024 LDMFD SP!,{R0-R3,PC}^ ] ; Virtual_TaskInfo ; Obtains information from the Virtual taskwindow module ; On entry ; R0 = 0 (actually we don't care) ; On exit ; R0 = 0 if not called from inside a virtual taskwindow, else non-zero TaskInfo MOV R0, #0 ; Always return not from here LDMFD SP!,{R0-R3,PC}^ ;R0 cmd string ;IP currently preferred instantiation IMPORT |__main| start SWI OS_EnterOS STR SP,svcstacktop ;record what a flat svcstack is TEQ PC,#0 NOP LDR ip,[IP] MOV R6,R0 SWI OS_GetEnv MOV sp,R1 ;stack at top of memory MOV R0,#&8000 LDR R2,=&AAAAAAAA [ OLD_VERSION TEQ R0,sp 00 STRNE R2,[R0],#4 TEQ R0,sp BNE %B00 | MOV R3, R2 MOV R4, R2 MOV R5, R2 ; TEQ R0,sp 00 STMIA R0!, {R2,R3,R4,R5} CMP R0,sp BLT %B00 MOV sp, #&10000 ; stack pointer at 32K to allow ; increasing wimpslot! ] MOV a2,R6 ;command tail MOV a1,ip ;worksp. MOV fp,#0 BL |__main| SWI OS_Exit ;**************** Start of Virtual mode interface routines ************* IMPORT CVSWIV EXPORT VSWIV VSWIV TST lr,#SVC_mode ;was it user mode? LDRNE pc,workOldSWIV ;no, goto old routine STR lr,templr LDR lr,svcstacktop TEQ lr,SP ;flat svcstack? LDRNE lr,templr LDRNE pc,workOldSWIV ;no, goto old routine MOV lr,#1 STR lr,worksemaphore TEQP pc,#SVC_mode ;Enable ints NOP LDR lr,workptr ;point at our workspace STMIA lr,{R0-lr}^ ;Save all user regs NOP MOV ip,lr LDR sp,stacktop LDR lr,templr STR lr,regs+15*4 MOV a1,ip BIC a2,lr,#&FC000003 LDR a2,[a2,#-4] MOV fp,#0 ADR lr,ToCode ORR lr,lr,#SVC_mode B CVSWIV ;must return w again EXPORT VPrefetchAbort VPrefetchAbort STR lr,templr MOV lr,#1 STR lr,worksemaphore TEQP pc,#SVC_mode ;Enable ints NOP LDR lr,workptr ;point at our workspace STMIA lr,{R0-lr}^ ;Save all user regs NOP MOV ip,lr LDR sp,stacktop LDR lr,templr SUB lr,lr,#4 ;adjust BIC R3,lr,#&FC000003 MOV R4,#4 B VWantAddr ;This is some static workspace, for when we don't have wksp ptr around. ;Used with care, we are still "reentrant" for use by different Wimp tasks. ;Set up anew each time we go into virtual mode. ;Its placed in the middle of the code that wants to use it to stay in ;addressing range. EXPORT workptr EXPORT workOldSWIV EXPORT worksemaphore EXPORT svcstacktop workptr & 0 ;Pointer to workspace workOldSWIV & 0 ;Place to forward SVC mode swi calls worksemaphore & 0 templr & 0 svcstacktop & 0 EXPORT VDataAbort VDataAbort STR lr,templr MOV lr,#1 STR lr,worksemaphore TEQP pc,#SVC_mode ;Enable ints NOP LDR lr,workptr ;point at our workspace STMIA lr,{R0-lr}^ ;Save all user regs NOP MOV ip,lr LDR sp,stacktop LDR lr,templr BIC R0,lr,#&FC000003 STR R0,regs+15*4 ;For use of pc-relative SUB lr,lr,#8 ;adjust BIC R0,lr,#&FC000003 LDR R1,[R0] ;instruction AND R2,R1,#&f0000 ;base register LDR R3,[ip,R2,LSR #16-2] ;get its contents TST R1,#(1:SHL:26) BNE isSTRLDR TST R1,#(1:SHL:23) ;direction MOVEQ R6,#-4 MOVNE R6,#4 MOV R4,#0 MOV R5,R1,LSL#16 02 MOVS R5,R5,LSL#1 ADDCS R4,R4,R6 BNE %BT02 TST R1,#(1:SHL:21) ;writeback ? SUBNE R3,R3,R4 STRNE R3,[ip,R2,LSR #16-2] B VWantAddr isSTRLDR TST R1,#(1:SHL:24) BEQ %FT01 ;post index MOV R4,R1,LSL#32-12 ;12 bits of offset MOV R4,R4,LSR#32-12 TST R1,#(1:SHL:25) BEQ %FT02 ;immed offset AND R5,R4,#2_1111 ;reg Rm LDR R5,[ip,R5,LSL#2] AND R6,R4,#2_1100000 ; ALU instruction types, no register specific shift amounts ; So we have to divide by 2 here to get the 4 instruction ; offsets 0x00, 0x10, 0x20, 0x30 ADD pc,pc,R6, ASR#1 & 0 MOV R6,R4,LSR#7 ;immed shift LSL 0x00 MOV R4,R5,LSL R6 B %FT02 & 0 MOVS R6,R4,LSR#7 ;immed shift LSR 0x10 ORREQ R6,R6,#32 MOV R4,R5,LSR R6 B %FT02 MOVS R6,R4,LSR#7 ;immed shift ASR 0x20 ORREQ R6,R6,#32 MOV R4,R5,ASR R6 B %FT02 MOVS R6,R4,LSR#7 ;immed shift ROR 0x30 BEQ itsRRX MOV R4,R5,ROR R6 B %FT02 itsRRX TEQ pc,lr,LSL#3 ;get aborted C flag MOV R4,R5,RRX 02 TST R1,#(1:SHL:23) SUBEQ R3,R3,R4 ;down ADDNE R3,R3,R4 ;up 01 MOV R4,#4 ; R3+R4 = access range, ip = worksp. ; resume to R0-R15 on stack IMPORT CVWantAddr VWantAddr STR lr,regs+15*4 ;now save proper pc [ DEBUG MOV R0,R3 ADR R1,addr MOV R2,#8 SWI XOS_ConvertHex8 LDR R0,[ip,#15*4] ADR R1,addr2 MOV R2,#8 SWI XOS_ConvertHex8 ADR R0,mesg SWI XOS_Write0 ] MOV a1,ip MOV a2,R3 MOV a3,R4 MOV fp,#0 ADR lr,ToCode+SVC_mode B CVWantAddr ;must return a1 again. [ DEBUG mesg = "Abort for addr &" addr = "00000000 at " addr2 = "00000000",13,10,0 ALIGN ] ;Return to user code, with callback semaphore zeroed. ;a1 points to workspace ToCode MOV lr,pc TST lr,#3 ADREQ R0,ToCodeErr SWIEQ OS_GenerateError TEQP pc,#SVC_mode+I_bit ;disable ints NOP LDR lr,worksemaphore SUBS lr,lr,#1 BNE VCallBack1 STR lr,worksemaphore MOV lr,a1 ;reg block to a SVC reg LDMIA lr,{R0-lr}^ ;load user regs NOP LDR lr,[lr,#15*4] ;user pc MOVS pc,lr ;into user mode and go! ToCodeErr & 0 = "Life is bad in ToCode",0 ALIGN IMPORT CVCallBack EXPORT VCallBack VCallBack MOV a1,IP MOV ip,a1 LDR sp,stacktop MOV lr,#1 VCallBack1 STR lr,worksemaphore TEQP pc,#SVC_mode ;enable ints NOP MOV fp,#0 ADR lr,ToCode+SVC_mode B CVCallBack ;must return a1 again. ;Regular Ticker CallEvery Centi-second EXPORT OurCallEvery OurCallEvery LDR IP,worksemaphore TEQ IP,#0 ADDNE IP,IP,#1 STRNE IP,worksemaphore MOVNES pc,lr STMFD SP!,{lr} MOV IP,pc TEQP pc,#I_bit+SVC_mode NOP STMFD SP!,{lr} SWI XOS_SetCallBack LDMFD SP!,{lr} TEQP IP,#0 NOP LDMFD SP!,{pc}^ ; Convert various sorts of events to C IMPORT CVUpCall EXPORT VUpCall VUpCall STMFD SP!,{R1-IP,LR} MOV a4,IP MOV sp,SP SUB SP,SP,#1024 MOV fp,#0 BL CVUpCall ADD SP,SP,#1024 LDMFD SP!,{R1-IP,PC}^ EXPORT VError VError SWI OS_GenerateError EXPORT VExit VExit SWI OS_Exit ;call in user mode to caught by VSWIV ; Convert various sorts of events to C IMPORT CExtUpCall EXPORT ExtUpCall ExtUpCall STMFD SP!,{R1-IP,LR} MOV a4,IP MOV sp,SP SUB SP,SP,#1024 MOV fp,#0 BL CExtUpCall ADD SP,SP,#1024 LDMFD SP!,{R1-IP,PC}^ IMPORT CExtError EXPORT ExtError ExtError MOV ip,R0 LDR sp,stacktop MOV fp,#0 BL CExtError SWI OS_GenerateError IMPORT CExtExit EXPORT ExtExit ExtExit MOV a1,IP MOV ip,a1 LDR sp,stacktop MOV fp,#0 BL CExtExit SWI OS_Exit IMPORT CExtWriteC K * &80000001 ;return K to pass vector on with input flag values ;return K-1 for VC CC ;return K+1 for VC CS ;return K-2 for VS CC EXPORT ExtWriteC ExtWriteC STMFD SP!,{R0-IP,LR} SUB SP,SP,#8 STMIA SP,{SP,LR}^ NOP MOV a2,IP MOV sp,SP SUB SP,SP,#1024 MOV fp,#0 BL CExtWriteC ADD SP,SP,#1024 LDMIA SP,{SP,LR}^ NOP ADD SP,SP,#8 CMP R0,#K LDMEQFD SP!,{R0-IP,PC}^ LDMFD SP!,{R0-IP,LR,PC} ; Convert various sorts of events to C IMPORT CNormWriteC ;return K to pass vector on with input flag values ;return K-1 for VC CC ;return K+1 for VC CS ;return K-2 for VS CC EXPORT NormWriteC NormWriteC STMFD SP!,{R0-IP,LR} SUB SP,SP,#8 STMIA SP,{SP,LR}^ NOP MOV a2,IP MOV sp,SP SUB SP,SP,#1024 MOV fp,#0 BL CNormWriteC ADD SP,SP,#1024 LDMIA SP,{SP,LR}^ NOP ADD SP,SP,#8 CMP R0,#K LDMEQFD SP!,{R0-IP,PC}^ LDMFD SP!,{R0-IP,LR,PC} IMPORT CNormUpCall EXPORT NormUpCall NormUpCall STMFD SP!,{R1-IP,LR} MOV a4,IP MOV sp,SP SUB SP,SP,#1024 MOV fp,#0 BL CNormUpCall ADD SP,SP,#1024 LDMFD SP!,{R1-IP,PC}^ IMPORT CNormError EXPORT NormError NormError MOV ip,R0 LDR sp,stacktop MOV fp,#0 BL CNormError SWI OS_GenerateError IMPORT CNormExit EXPORT NormExit NormExit MOV a1,IP MOV ip,a1 LDR sp,stacktop MOV fp,#0 BL CNormExit SWI OS_Exit ; Mode changing ; Now we use R12 as stack, less messy, and idempotent EXPORT usermode usermode MOV a2,lr TEQP pc,#USR_mode NOP MOV pc,a2 EXPORT svcmode svcmode MOV a2,lr SWI XOS_EnterOS MOV pc,a2 EXPORT CallEscapeHandler CallEscapeHandler MOV ip, sp STMFD sp!, {v1, v2, fp, ip, lr, pc} SUB fp, ip, #4 MOV v1, fp ; save fp and SP MOV v2, SP MOV SP, sp ; pass our stack on MOV ip, a3 ; R11 escape condition MOV sp, a2 ; R12 MOV lr, pc MOV pc, a1 ; call user escape handler MOV a1, sp ; R12 is return call back flag MOV SP, v2 ; restore fp and SP MOV fp, v1 LDMEA fp, {v1, v2, fp, sp, pc}^ END