Liren Large Software Subsidy 7

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Assembly Source File | 1991-08-20 | 16.6 KB | 515 lines

;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ;% Copyright (C) 1991, by WATCOM Systems Inc. All rights % ;% reserved. No part of this software may be reproduced % ;% in any form or by any means - graphic, electronic or % ;% mechanical, including photocopying, recording, taping % ;% or information storage and retrieval systems - except % ;% with the written permission of WATCOM Systems Inc. % ;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ; ; startup code for WATCOM C 386 Version 8.5 ; ; This must be assembled using the following command: ; 386asm cstart ; ; NOTE: All C library data should be defined in CRWDATA.ASM -- That way ; it's also available to ADS applications (who use ADSSTART.ASM). ; name cstart .387 .386p assume nothing extrn __CMain : near extrn __DOSseg__ : near extrn _edata : byte ; end of DATA (start of BSS) extrn _end : byte ; end of BSS (start of STACK) extrn _dynend : dword extrn _curbrk : dword extrn _psp : word extrn _osmajor : byte extrn _osminor : byte extrn _STACKLOW : dword extrn _STACKTOP : dword extrn _child : dword extrn __no87 : word extrn _Extender : byte extrn _Envptr : dword extrn _Envseg : word extrn __FPE_handler : dword extrn ___FPE_handler : dword DGROUP group _NULL,_AFTERNULL,CONST,_DATA,DATA,_emu_inits,_emu_init,_emu_inite,EXEC_S,EXEC,EXEC_E,XIB,XI,XIE,_BSS,STACK ; this guarantees that no function pointer will equal NULL ; (WLINK will keep segment 'BEGTEXT' in front) ; This segment must be at least 4 bytes in size to avoid confusing the ; signal function. BEGTEXT segment use32 word public 'CODE' assume cs:BEGTEXT forever: jmp short forever nop nop nop nop assume cs:nothing BEGTEXT ends _TEXT segment use32 word public 'CODE' assume ds:DGROUP _NULL segment para public 'BEGDATA' __nullarea label word db 01h,01h,01h,00h public __nullarea _NULL ends _AFTERNULL segment word public 'BEGDATA' _AFTERNULL ends CONST segment word public 'DATA' CONST ends _emu_inits segment word public 'DATA' _emu_start label word _emu_inits ends _emu_init segment word public 'DATA' __emulator label word ;; dd __init87emu ;; dd __fini87emu _emu_init ends _emu_inite segment word public 'DATA' _emu_end label word _emu_inite ends EXEC_S segment word public 'DATA' EXEC_S ends EXEC segment word public 'DATA' EXEC ends EXEC_E segment word public 'DATA' EXEC_E ends XIB segment word public 'DATA' xistart label byte XIB ends XI segment word public 'DATA' XI ends XIE segment word public 'DATA' xiend label byte XIE ends _DATA segment word public 'DATA' X_ERGO equ 0 X_RATIONAL equ 1 X_PHARLAP_V2 equ 2 X_PHARLAP_V3 equ 3 X_PHARLAP_V4 equ 4 X_INTEL equ 5 __GDAptr dd 0 ; IGC and Intel Code Builder GDA address __D16Infoseg dw 0020h ; DOS/4G kernel segment public __GDAptr public __D16Infoseg _DATA ends DATA segment word public 'DATA' DATA ends _BSS segment word public 'BSS' _BSS ends STACK_SIZE equ 1000h STACK segment para stack 'STACK' db (STACK_SIZE) dup(?) STACK ends assume nothing public _cstart_ public __exit assume cs:_TEXT _cstart_ proc near jmp short around ; ; copyright message ; db "WATCOM C 386 Run-Time system. " db "(c) Copyright by WATCOM Systems Inc. 1989, 1991." db " All rights reserved." ; ; miscellaneous code-segment messages ; ConsoleName db "con",00h __saved_DS dw 0 ; save area for DS for interrupt routines around: sti ; enable interrupts assume ds:DGROUP PSP_SEG equ 24h ENV_SEG equ 2ch and esp,0fffffffch ; make sure stack is on a 4 byte bdry mov ebx,esp ; get sp mov _STACKTOP,ebx ; set stack top mov _curbrk,ebx ; set first available memory location mov ax,PSP_SEG ; get segment address of PSP mov _psp,ax ; save segment address of PSP ; ; get DOS & Extender version number ; mov ebx,'PHAR' ; set ebx to 0 sub eax,eax ; set eax to 0 mov ah,30h int 21h ; modifies eax,ebx,ecx,edx mov _osmajor,al mov _osminor,ah mov ecx,eax ; remember DOS version number sub esi,esi ; offset 0 for environment strings mov edi,81H ; DOS command buffer es:edi shr eax,16 ; get top 16 bits of eax cmp ax,'DX' ; if top 16 bits = "DX" jne not_pharlap ; then its pharlap sub bl,'0' ; - save major version number mov al,bl ; - (was in ascii) mov bx,14h ; - get value of Phar Lap data segment mov cx,ENV_SEG ; - PharLap environment segment jmp short know_ext1 ; else not_pharlap: ; - see if Intel Code Builder cmp ax,'BC' ; - if Intel Code Builder jne not_Intel ; - ... then GDA_PSPA equ 16 ; - offset into GDA to PSP address GDA_LDPT equ 28 ; - offset into GDA to load address mov __GDAptr,edx ; - save address of GDA mov esi,edx ; - get address of GDA mov edx,GDA_LDPT[esi] ; - get application load point address mov ebx,esp ; - calc amount of memory to keep sub ebx,edx ; - ... mov ah,4Ah ; - resize to minimum memory int 21h ; - ... mov bx,ds ; - just use ds (FLAT model) mov _psp,ds ; - save segment address of PSP mov eax,GDA_PSPA[esi] ; - get address of PSP add edi,eax ; - add address of PSP sub esi,esi ; - zero esi mov si,02ch[eax] ; - get environment segment into si shl esi,4 ; - convert to flat address mov cx,ds ; - segment to access environment area mov al,X_INTEL ; - indicate Intel Code Builder know_ext1:jmp short know_extender ; else not_Intel: ; - mov dx,78h ; - see if Rational DOS/4G mov ax,0FF00h ; - ... int 21h ; - ... cmp al,0 ; - ... je short not_DOS4G ; - quit if not Rational DOS/4G mov ax,gs ; - get segment address of kernel cmp ax,0 ; - if not zero je short rat9 ; - then mov __D16Infoseg,ax ; - - remember it rat9: ; - endif mov al,X_RATIONAL ; - indicate Rational 32-bit Extender mov bx,ds ; - just use ds (FLAT model) mov _psp,es ; - save segment address of PSP mov cx,es:[02ch] ; - get environment segment into cx jmp short know_extender ; else not_DOS4G: ; - mov dx,ds ; - save ds mov cx,PSP_SEG ; - get PSP segment descriptor mov ds,cx ; - ... into ds mov cx,ds:[02ch] ; - get environment segment into cx mov ds,dx ; - restore ds mov bx,17h ; - get writeable code segment for Ergo mov al,X_ERGO ; - indicate Ergo OS/386 know_extender: ; endif mov _Extender,al ; record extender type mov es,bx ; get access to code segment mov es:__saved_DS,ds ; save DS value mov _Envptr,esi ; save address of environment strings mov _Envseg,cx ; save segment of environment area push esi ; save address of environment strings ; ; copy command line into bottom of stack ; mov es, _psp ; point to PSP mov edx,offset DGROUP:_end add edx,0FH and dl,0F0H sub ecx,ecx mov cl,es:[edi-1] ; get length of command cld ; set direction forward mov al,' ' rep scasb lea esi,-1[edi] mov edi,edx mov bx,es mov dx,ds mov ds,bx mov es,dx ; es:edi is destination je noparm inc ecx rep movsb noparm: sub al,al stosb ; store NULLCHAR stosb ; assume no pgm name pop esi ; restore address of environment strings dec edi ; back up pointer 1 push edi ; save pointer to pgm name push edx ; save ds(stored in dx) mov ds,es: _Envseg ; get segment addr of environment area sub ebp,ebp ; assume "no87" env. var. not present L1: mov eax,[esi] ; get first 4 characters or eax,20202020h ; map to lower case cmp eax,'78on' ; check for "no87" jne short L2 ; skip if not "no87" cmp byte ptr 4[esi],'=' ; make sure next char is "=" jne short L2 ; no inc ebp ; - indicate "no87" was present L2: cmp byte ptr [esi],0 ; end of string ? lodsb jne L2 ; until end of string cmp byte ptr [esi],0 ; end of all strings ? jne L1 ; if not, then skip next string lodsb inc esi ; point to program name inc esi ; . . . ; ; copy the program name into bottom of stack ; L3: cmp byte ptr [esi],0 ; end of pgm name ? movsb ; copy a byte jne L3 ; until end of pgm name pop ds ; restore ds pop esi ; restore address of pgm name mov ebx,esp ; end of stack in data segment assume ds:DGROUP mov __no87,bp ; set state of "no87" enironment var mov _STACKLOW,edi ; save low address of stack mov _dynend,ebx ; set top of dynamic memory area mov ecx,offset DGROUP:_end ; end of _BSS segment (start of STACK) mov edi,offset DGROUP:_edata; start of _BSS segment sub ecx,edi ; calc # of bytes in _BSS segment mov dl,cl ; save bottom 2 bits of count in edx shr ecx,2 ; calc # of dwords sub eax,eax ; zero the _BSS segment rep stosd ; ... mov cl,dl ; get bottom 2 bits of count and cl,3 ; ... rep stosb ; ... mov eax,offset DGROUP:_emu_start mov edx,offset DGROUP:_emu_end cmp edx,eax ; if 387 emulator present je short no_emu ; then call [eax] ; - initialize emulator no_emu: ; endif call initrtns ; call initializer routines mov eax,offset DGROUP:_end ; cmd buffer pointed at by EAX add eax,0FH and al,0F0H mov edx,esi ; point EDX at program name sub ebp,ebp ; ebp=0 indicate end of ebp chain call __CMain _cstart_ endp ; don't touch AL in __exit_, it has the return code __exit proc near jmp short ok public __exit_with_msg ; input: EAX - pointer to message to print ; EDX - exit code __exit_with_msg: push edx ; save return code push eax ; save address of msg mov edx,offset ConsoleName mov ax,03d01h ; write-only access to screen int 021h mov bx,ax ; get file handle pop edx ; restore address of msg mov esi,edx ; get address of msg cld ; make sure direction forward L4: lodsb ; get char cmp al,0 ; end of string? jne L4 ; no mov ecx,esi ; calc length of string sub ecx,edx ; . . . dec ecx ; . . . mov ah,040h ; write out the string int 021h ; . . . pop eax ; restore return code ok: push eax ; save return code mov eax,offset DGROUP:_emu_start mov edx,offset DGROUP:_emu_end cmp edx,eax ; if 387 emulator present je no_emu1 ; then call 4[eax] ; - finalize emulator no_emu1: ; endif pop eax ; restore return code mov ah,04cH ; DOS call to exit with return code int 021h ; back to DOS __exit endp initrtns proc near push esi ; save esi mov esi,offset DGROUP:xistart; get start addr of table mov edi,offset DGROUP:xiend ; get end addr of table init1: cmp esi,edi ; loop through the table jae init9 ; - quit if done sub edi,4 ; - point to start of entry mov eax,[edi] ; - get address of routine or eax,eax ; - check for null entry je init1 ; - try next one if it is null call eax ; - call initializer routine jmp init1 ; endloop init9: pop esi ; restore esi ret ; return initrtns endp public __GETDS __GETDS proc near mov ds,cs:__saved_DS ; load saved DS value ret ; return __GETDS endp _TEXT ends end _cstart_