io Programmo 23

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Assembly Source File | 1998-10-26 | 8.9 KB | 396 lines

; ; GRDP ; ; Copyright(c) LADsoft ; ; David Lindauer, camille@bluegrass.net ; ; ; Regs.asm ; ; Function: Handle register display and input ; ;MASM MODE .model small .386 include eprints.inc include emtrap.inc include einput.inc include edis.inc include eoptions.inc include ehistory.inc PUBLIC DisplayRegisters, ModifyRegisters, ReadReg .code ; ; This is a list corresponding ASCII names for general purpose regs ; with the address the value can be found at; ; peax dw offset RegdumpEAX db 13,10,"eax:",0 pebx dw offset RegdumpEBX db "ebx:",0 pecx dw offset RegdumpECX db "ecx:",0 pedx dw offset RegdumpEDX db "edx:",0 pesi dw offset RegdumpESI db "esi:",0 pedi dw offset RegdumpEDI db "edi:",0 pebp dw offset RegdumpEBP db 13,10,"ebp:",0 pesp dw offset RegdumpESP db "esp:",0 peip dw offset RegdumpEIP db "eip:",0 dw 0 ; ; a list of 8-bit register names ; pal dw offset RegdumpEAX db 13,10,"al:",0 dw offset RegdumpEAX+1 db "ah:",0 dw offset RegdumpEBX db "bl:",0 dw offset RegdumpEBX+1 db "bh:",0 dw offset RegdumpECX db "cl:",0 dw offset RegdumpECX+1 db "ch:",0 dw offset RegdumpEDX db 13,10,"dl:",0 dw offset RegdumpEDX+1 db "dh:",0 dw 0 ; ; a list of 16-bit register names ; pax dw offset RegdumpEAX db 13,10,"ax:",0 dw offset RegdumpEBX db "bx:",0 dw offset RegdumpECX db "cx:",0 dw offset RegdumpEDX db "dx:",0 dw offset RegdumpESI db "si:",0 dw offset RegdumpEDI db "di:",0 dw offset RegdumpEBP db 13,10,"bp:",0 dw offset RegdumpESP db "sp:",0 dw offset RegdumpEIP db "ip:",0 pds dw offset RegdumpDS db 13,10,"ds: ",0 PES dw offset RegdumpES db "es:",0 pfs dw offset RegdumpFS db "fs:",0 pgs dw offset RegdumpGS db "gs:",0 Pss dw offset RegdumpSS db "ss:",0 pcs dw offset RegdumpCS db "cs:",0 dw 0 peflags dw offset RegdumpFLAGS db "eflags:",0 dw 0 flm label byte db 11 dd "NVOV" db 10 dd "UPDN" db 9 dd "DIEI" db 7 dd "PLMI" db 6 dd "NZZR" db 4 dd "NAAC" db 2 dd "POPE" db 0 dd "NCCY" db -1 db 0 ; ; Print a general purpose reg and it's value ; rPutDword PROC test [optdword],0ffh jz rPutWord lods word ptr cs:[si]; Get pointer to val mov bx,ax mov eax,[bx] ; Get val push eax ; mov bx,si ; Get text pointer call olMessage pop eax ; call printdword ; Print value call printspace ; ret rPutDword ENDP ; ; Print a segment reg and its value ; rPutWord PROC lods word ptr cs:[si]; Get pointer to value mov bx,ax mov ax,[bx] ; Get value push ax ; mov bx,si ; Pointer to text call olMessage pop ax ; call printword ; Print value call printspace ; ret rPutWord ENDP ; ; Print either the GP regs or the SEG regs ; INPUT: DX has the address of the appropriate print routine ; SI points to text ; By implication, two consecutive bytes of 0 exit the routine, else we ; print each string until we reach that 00 00 ; PrintaFew PROC call dx ; Call the print routine pf_lp: lods byte ptr cs:[si]; Wade past the text or al,al ; jnz pf_lp ; test WORD PTR cs:[si],-1 ; See if trailer found jnz PrintAFew ; Go print another ret PrintAFew ENDP ; ; try to find a match for a register spec ; INPUT: SI points at the input line where we might find a register by name ; DI points to an EAX structure consisting of a pointer to a bucket ; to put EAX into, followed by a display string of 'EAX' ; OUTPUT:SI is moved past the register if we found one, else same ; DI points to bucket to hold this register value if register found ; skimreg PROC push di ;save address of structure push si ;save address of input xchg si,di ;di now input, si is structure add si,2 ;go past EAX bucket pointer to str srlp: cmp byte ptr cs:[si],' ' ;anything below a space jnc oktry ;is OK, so skip 0D, 0A at EAX inc si ;goto next character jmp srlp ;until letter is found oktry: cmp byte ptr cs:[si],':' ;colon follows all register names jz match ;so if all alike, we found our reg cmps byte ptr cs:[si],es:[di] ;else do a character match jz oktry ;if a match, keep going to colon pop di ;else pop address of input to di add sp,2 ;clear struct address off stack srlp2: lods byte ptr cs:[si] ;find terminating 0, following colon or al,al ;is this it? jnz srlp2 ;keep looking until found test word ptr cs:[si],0ffffh ;table ends with word of 0 xchg si,di ;get our regs straightened out jnz skimreg ;and examine next struct sub al,al ;no find, so inc al ;return no carry ret match: add sp,2 ;clear input address off stack sub eax,eax ;clear out EAX xchg si,di ;SI now input past found register pop di ;di points to top struct mov di,cs:[di] ;point to his bucket stc ;indicate register found ret skimreg ENDP ; ; search all the name tables for a match ; INPUT: SI points at the input line where we expect to find a register ; OUTPUT: ZR if found a non-segment register, NZ if we didn't ; CY if the request was NOT for a segment register, NC if it was ; SI moved past the register on the input line ; FindRegister PROC mov di,offset cs:peax ;find pointer to EAX bucket call skimreg ;look for register string match mov cl,4 ;used for dword length jc frnoseg ;carry means we found dword reg mov di,offset cs:pal ;else look for byte reg call skimreg ;save technique mov cl,1 ;set byte length jc frnoseg ;in case we found it mov di,offset cs:peflags ;else maybe user doing flags? call skimreg ;try 'eflags' mov cl,4 ;say 4 bytes for this jc frnoseg ;if found mov bl,[si+1] ;else bl=2d char in input string mov di,offset cs:pax ;look for word regs call skimreg ;in the table mov cl,2 ;assume word jnc frnotfound ;if not found, bl is ??? cmp bl,'s' ;might it be a segment reg? stc ;assume not??? jnz frnoseg ;jmp if not clc ;else clear carry frnoseg: mov al,0ffH ;set ZF without affecting carry flag inc al ret ;and return success frnotfound: sub ax,ax ;set NZ inc ax stc ;and the carry ret FindRegister ENDP ; ; read the value of a reg (used by input routines) ; INPUT: SI points at the input line ; OUTPUT:If we found a byte or word register, EAX holds the zero-extended ; value that was in the corresponding bucket. ; If we found a dword register, EAX holds the dword value ; NZ if register not found by name, but still might be a number ; Else, NC if segment reg, CY if non-segment reg found ; SI moved past a register found by name, else not moved ; ReadReg PROC push ecx ;ECX holds ??? call FindRegister ;see if we found a non-segment reg jnz notreg ;if not, jmp pushf ;save flags (carry?) mov eax,[di] ;get value from bucket cmp cl,4 ;was it a dword? jz rr_exit ;if so, exit movzx eax,ax ;else zero extend into EAX cmp cl,2 ;was it a word register jz rr_exit ;if so, we have it movzx eax,al ;else zero extend EAX rr_exit: popf ;restore flags notreg: pop ecx ;and ECX ret ReadReg ENDP ; ; Read value for a register back into memory (R) command ; ReadRegValue PROC call WadeSpace jz doregprompt inc si cmp al,':' jz ReadRegValue cmp al,'=' jz ReadRegValue dec si call ReadNumber ret doregprompt: push bx ; Else put up prompt push cx ; PRINT_MESSAGE <13,10,": "> call histoff call GetInputLine ; Get input line call histon pop cx ; pop bx ; call WadeSpace ; Ignore spaces jz short rr_out ; Quit if so call ReadNumber ret rr_out: stc ret ReadRegValue ENDP ; ; main 'Reg' command ; ModifyRegisters PROC call wadespace ; Wade through spaces jz DisplayRegisters ; Display regs call FindRegister jnz badreg push di call ReadRegValue pop di jc badreg2 cmp cl,4 jnz wordreg mov [di],eax clc ret wordreg: cmp cl,2 jnz bytereg mov [di],ax badreg2: clc ret badreg: stc ret bytereg: mov [di],al ret ModifyRegisters ENDP putflags PROC mov si,offset cs:flm putflags2: lods byte ptr cs:[si] or al,al js pfdone movzx ax,al bt word ptr [RegdumpFLAGS],ax lods dword ptr cs:[si] mov edx,eax jc isclr shr edx,16 isclr: xchg dh,dl call PutChar xchg dl,dh call PutChar call PrintSpace jmp putflags2 pfdone: ret putflags ENDP ; ; Display the processor regs ; DisplayRegisters PROC mov word ptr [RegdumpEIP+2],0 ;clear high word of EIP pushfd ;move eflags pop eax ;to EAX shr eax,16 ;get upper 16 flagbits mov word ptr [RegdumpFLAGS+2],ax ;save in high flag bucket mov si, offset cs:peax ; Print GP regs mov dx,offset cs:rPutDword ; with the DWORD function call PrintAFew ; Print them mov si,offset cs:peflags ;Put the flags call rPutDword call putflags mov si,offset cs:pds ; Now put the segs mov dx,offset cs:rPutWord call PrintAFew mov bx,word ptr [RegdumpEIP] ; Dissassemble at current code pointer mov dx,[RegdumpCS] call DisOneLine clc ret DisplayRegisters ENDP END