PC Extra Super CD 1998 January

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Assembly Source File | 1997-02-22 | 33.8 KB | 1,017 lines

; Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details ; -*- asm -*- ; ;----------------------------------------------------------------------------- ; PMODE/DJ - A stub with an inbuilt DPMI dos extender. (like PMODE/W) ; ; PMODE/DJ includes PMODE V3.07, which is (c) by Thomas Phytel ; PMODE/DJ was written by m.grimrath@tu-bs.de. Changes were made both to ; stub.asm and pmode.asm. ; stub.asm - changed to compile with tasm and switches into PM via PMODE ; pmode.asm - added some features, like exceptionhandling and PIC ; reprogramming, etc. See pmodedj.doc for details ;----------------------------------------------------------------------------- ; ; KLUDGE-WARNING! ; ; So you say you want to change this file, right? Are you really sure ; that's a good idea? Let me tell you a bit about the pitfalls here: ; ; * Some code runs in protected mode, some in real-mode, some in both. ; * Some code must run on a 8088 without crashing it. ; * Registers and flags may be expected to survive for a long time. ; * The code is optimized for size, not for speed or readability. ; * Some comments are parsed by other programs. ; ; You still want to change it? Oh well, go ahead, but don't come ; crying back saying you weren't warned. ; ;----------------------------------------------------------------------------- ; djgpp stub loader ; ; (C) Copyright 1993-1995 DJ Delorie ; ; Redistribution and use in source and binary forms are permitted ; provided that: (1) source distributions retain this entire copyright ; notice and comment, (2) distributions including binaries display ; the following acknowledgement: ``This product includes software ; developed by DJ Delorie and contributors to the djgpp project'' ; in the documentation or other materials provided with the distribution ; and in all advertising materials mentioning features or use of this ; software, and (3) binary distributions include information sufficient ; for the binary user to obtain the sources for the binary and utilities ; required to built and use it. Neither the name of DJ Delorie nor the ; names of djgpp's contributors may be used to endorse or promote ; products derived from this software without specific prior written ; permission. ; ; THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR ; IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED ; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. ; ; Revision history: ; ; 93/12/05 DJ Delorie Initial version v2.00, requires DPMI 0.9 ; 94/10/13 CW Sandmann v2.01, accumlated changes: 60K load bug, limits, cwsdpmi, optimization ; 94/10/29 CW Sandmann v2.03, M Welinder changes; cwsdpmi load anywhere, size decrease ; ideal p386 assume cs:_TEXT, ds:DGROUP, es:nothing, ss:nothing, fs:_TEXT group DGROUP _DATA, _BSS SEGMENT _TEXT PUBLIC USE16 'CODE' ;***************************************************************************** ; structure definitions ; coff_magic = 0 ; from coff header aout_entry = 16 ; from aout header s_paddr = 8 ; from section headers s_vaddr = 12 s_size = 16 s_scnptr = 20 stack_sz = 180h ; must be a multiple of 16! SW_FLAGS = 0002h ; switch flags for PMODE EXCEPTION_HANDLER = 0 EXTRN pm_info:near, pm_init:near ;----------------------------------------------------------------------------- ; Interface to 32-bit executable: ; ; cs:eip according to COFF header ; ds 32-bit data segment for COFF program ; fs selector for our data segment (fs:0 is stubinfo) ; ss:sp our stack (ss to be freed) ; <others> All unspecified registers have unspecified values in them. ;----------------------------------------------------------------------------- ; This is the stubinfo structure. The presence of this structure ; indicates that the executable is a djgpp v2.00 executable. ; Fields will never be deleted from this structure, only obsoleted. ; label stubinfo byte stubinfo_magic \ ; char [16] db "go32stub, v 2.00" ; version may change, [0..7] won't stubinfo_size \ ; unsigned long dw stubinfo_end,0 ; bytes in structure stubinfo_minstack \ ; unsigned long dd 40000h ; minimum amount of DPMI stack space (256K) stubinfo_memory_handle \ ; unsigned long dd 0 ; DPMI memory handle stubinfo_initial_size \ ; unsigned long dd 0 ; size of initial segment stubinfo_minkeep \ ; unsigned short dw 16384 ; amount of automatic real-mode buffer stubinfo_ds_selector \ ; unsigned short dw 0 ; our DS selector (used for transfer buffer) stubinfo_ds_segment \ ; unsigned short dw 0 ; our DS segment (used for simulated calls) stubinfo_psp_selector \ ; unsigned short dw 0 ; PSP selector stubinfo_cs_selector \ ; unsigned short dw 0 ; to be freed stubinfo_env_size \ ; unsigned short dw 0 ; number of bytes of environment stubinfo_basename \ ; char [8] db 8 dup (0) ; base name of executable to load (asciiz if < 8) ;db "A",0,0,0,0,0,0,0 stubinfo_argv0 \ ; char [16] db 16 dup (0) ; used ONLY by the application (asciiz if < 16) stubinfo_dpmi_server \ ; char [16] db 16 dup (0) ; used by stub to load DPMI server if no DPMI ; already present. Not used by PMODEDJ align 4 label stubinfo_end byte ;***************************************************************************** ; CODE ; THIS IS NOW IN PADSEC! ; db "The PMODEDJ.EXE stub loader is Copyright (C) 1993-1995 DJ Delorie. ",13,10 ; db "Permission granted to use for any purpose provided this copyright ",13,10 ; db "remains present and unmodified. ",13,10 ; db "This only applies to the stub, and not neccessarily the whole program.",13,10 ;----------------------------------------------------------------------------- ; First, set up our memory and stack environment start: ; execution starts here push _DATA pop ds cld mov bp,_STACK + (stack_sz/16) ; end of needed memory sub bp,_TEXT ; bp = # of paragraphs without psp mov [dos_block_seg],es ; save psp ;----------------------------------------------------------------------------- ; Check that we have DOS 3.00 or later. (We need this because earlier ; versions don't supply argv[0] to us and will scrog registers on dpmi exec). mov ah, 030h int 021h mov [dos_major],al cmp al, 3 jae short dos3ok mov dx, offset msg_bad_dos jmp error dos3ok: ;----------------------------------------------------------------------------- ; Get DPMI information before doing anything 386-specific mov ax,SW_FLAGS call pm_info ; get protected mode info jnc short @@ok jmp error_in_modesw @@ok: mov [modesw_mem], bx push cs pop fs cmp ch,3 jz short @@dpmi ; PMODE/DJ is active - allocate a separate transferbuffer mov bx, bp add bx, 10h ; extra for psp mov es, [dos_block_seg] mov ah, 04ah int 021h ; resize our memory block jc error_no_dos_memory call include_umb mov ah,48h mov bx,[stubinfo_minkeep] shr bx,4 int 21h ; Allocate transbuffer jnc short @@w1 call restore_umb jmp error_no_dos_memory @@w1: mov [fs:stubinfo_ds_segment],ax call restore_umb jmp short @@cont ; A DPMI host is active - this loader can be overwritten @@dpmi: shl bp, 4 cmp bp, [stubinfo_minkeep] ja short @@w2 mov bp, [stubinfo_minkeep] @@w2: mov [fs:stubinfo_minkeep], bp mov bx, bp inc bh ; Add extra for psp shr bx, 4 mov es, [dos_block_seg] mov ah, 04ah int 021h ; resize our memory block jc error_no_dos_memory mov [fs:stubinfo_ds_segment], cs @@cont: ;----------------------------------------------------------------------------- ; Scan environment for the stub's full name after environment mov es, [dos_block_seg] mov es, [es:02ch] ; get environment segment xor di, di ; begin search for NUL/NUL (di = 0) mov cx, 0ff04h ; effectively `infinite' loop xor al, al scan_environment: repne scasb ; search for NUL scasb jne short scan_environment ; no, still environment scasw ; adjust pointer to point to prog name ;----------------------------------------------------------------------------- ; copy the filename to loadname sub al,al push di mov cx,-1 repne scasb not cx mov [fs:stubinfo_env_size], di pop si mov di,offset loadname push ds push es push ds pop es pop ds rep movsb pop ds mov bx,di @@lp2: dec bx cmp [byte ptr bx],'\' ; always succeeds, because filename jne short @@lp2 ; is qualified inc bx cmp [byte ptr stubinfo_basename+0], 0 je short no_symlink ;----------------------------------------------------------------------------- ; Replace the stub's file name with the link's name after the directory mov cx, 8 ; max length of basename mov di, offset stubinfo_basename ; pointer to new basename @@b11: mov al, [cs:di] ; get next character inc di or al, al ; end of basename? je short @@f12 mov [bx], al ; store character inc bx loop @@b11 ; eight characters? @@f12: mov [dword ptr bx+0], 04558452eh ; append ".EXE" add bx, 4 mov [byte ptr bx], 0 no_symlink: ;----------------------------------------------------------------------------- ; Load the COFF information from the file mov ax, 03d00h ; open file for reading mov dx, offset loadname int 021h jc error_no_progfile ; do rest of error message mov [program_file], ax ; store for future reference mov bx, ax mov cx, exe_header_length mov dx, offset exe_header mov ah, 03fh ; read EXE header int 021h xor dx, dx ; dx = 0 xor cx, cx ; offset of COFF header mov ax, [exe_magic] cmp ax, 0014ch ; COFF? je short file_is_just_coff cmp ax, 05a4dh ; EXE magic value jne error_not_exe mov dx, [exe_sectors] shl dx, 9 ; 512 bytes per sector mov bx, [exe_bytes_last_page] or bx, bx ; is bx = 0 ? je short @@f13 sub dh, 2 ; dx -= 512 add dx, bx @@f13: file_is_just_coff: ; cx:dx is offset mov [word ptr coff_offset+0], dx mov [word ptr coff_offset+2], cx mov ax, 04200h ; seek from beginning mov bx, [program_file] int 021h mov cx, coff_header_length mov dx, offset coff_header mov ah, 03fh ; read file (bx = handle) int 021h cmp ax, coff_header_length jne short @@f21 cmp [word ptr coff_header + coff_magic], 0014ch @@f21: jne error_not_coff mov eax, [dword ptr aout_header + aout_entry] mov [start_eip], eax mov ecx, [coff_offset] mov eax, [dword ptr text_section + s_scnptr] add eax, ecx mov [text_foffset], eax mov eax, [dword ptr data_section+ s_scnptr] add eax, ecx mov [data_foffset], eax mov ebx, [dword ptr bss_section + s_vaddr] mov eax, [dword ptr bss_section + s_size] add ebx, eax mov eax, 00010001h cmp ebx, eax jae short @@f1 mov ebx, eax ; ensure 32-bit segment @@f1: add ebx, 0000ffffh ; ensure 64K rounded xor bx, bx ; clear rounded bits mov [fs:stubinfo_initial_size], ebx ;----------------------------------------------------------------------------- ; Set up for the DPMI environment call include_umb mov bx, [modesw_mem] or bx, bx ; or clears carry jz short @@noa mov ah, 048h ; allocate memory for the DPMI host int 021h jnc short @@noa call restore_umb jmp error_no_dos_memory @@noa: push ax call restore_umb pop es mov ax,SW_FLAGS ; switch flags call pm_init ; attempt to switch jc error_in_modesw ;----------------------------------------------------------------------------- ; We're in protected mode at this point. IF EXCEPTION_HANDLER NE 0 push es ds mov bx,cs mov ax,000Ah int 31h ; create alias descriptor jc perror_no_selectors mov es,ax mov [es:offset exception_vector],ds mov bx,0 sub edx,edx mov dx,offset exception_code mov cx,cs @@ll: mov ax,203h int 31h add dx,EXCEPTION_SIZE inc bx cmp bx,32 jne @@ll pop ds es ENDIF mov bx,cs mov ax,000Ah int 31h ; create alias descriptor jc perror_no_selectors mov fs,ax mov [fs:stubinfo_psp_selector],es mov [fs:stubinfo_ds_selector],fs mov [fs:stubinfo_cs_selector],ds push ds pop es xor ax, ax ; AX = 0x0000 mov cx, 1 int 031h ; allocate LDT descriptor jc short @@f2 mov [client_cs], ax xor ax, ax ; AX = 0x0000 ; mov cx, 1 ; already set above int 031h ; allocate LDT descriptor @@f2: jc perror_no_selectors mov [client_ds], ax ; Try getting a DPMI 1.0 memory block first, then try DPMI 0.9 ; Note: This causes the Borland Windows VxD to puke, commented for now with ;* ;* mov ax, 0x0504 ;* xor ebx, ebx ; don't specify linear address mov ecx, [stubinfo_initial_size + 0] ;* mov edx, 1 ; allocate committed pages ;* int 0x31 ; allocate memory block ;* jc try_old_dpmi_alloc ;* mov client_memory[0], ebx ;* mov fs:stubinfo_memory_handle[0], esi ;* jmp got_dpmi_memory try_old_dpmi_alloc: mov ax, 00501h mov bx, [word ptr stubinfo_initial_size + 2] ; mov cx, stubinfo_initial_size[0] ;Set above int 031h ; allocate memory block jc perror_no_dpmi_memory mov [word ptr client_memory + 2], bx mov [word ptr client_memory + 0], cx mov [word ptr fs:stubinfo_memory_handle + 2], si mov [word ptr fs:stubinfo_memory_handle + 0], di got_dpmi_memory: mov ax, 00007h mov bx, [client_cs] ; initialize client CS mov cx, [word ptr client_memory + 2] mov dx, [word ptr client_memory + 0] int 031h ; set segment base address mov ax, 00009h ; mov bx, [client_cs] ; already set above mov cx, cs ; get CPL and cx, 00003h shl cx, 5 push cx ; save shifted CPL for below or cx, 0c09bh ; 32-bit, big, code, non-conforming, readable int 031h ; set descriptor access rights mov ax, 00008h ; mov bx, [client_cs] ; already set above mov cx, [word ptr stubinfo_initial_size + 2] dec cx mov dx, 0ffffh int 031h ; set segment limit mov ax, 00007h mov bx, [client_ds] ; initialize client DS mov cx, [word ptr client_memory + 2] mov dx, [word ptr client_memory + 0] int 031h ; set segment base address mov ax, 00009h ; mov bx, [client_ds] ; already set above pop cx ; shifted CPL from above or cx, 0c093h ; 32-bit, big, data, r/w, expand-up int 031h ; set descriptor access rights mov ax, 00008h ; mov bx, [client_ds] ; already set above mov cx, [word ptr stubinfo_initial_size + 2] dec cx mov dx, 0ffffh int 031h ; set segment limit ;----------------------------------------------------------------------------- ; Load the program data mov ax, 00100h mov bx, 00f00h ; 60K DOS block size int 031h ; allocate DOS memory jnc short @@f1 cmp ax, 00008h jne perror_no_dos_memory mov ax, 00100h ; try again with new value in bx int 031h ; allocate DOS memory jc perror_no_dos_memory @@f1: mov [dos_block_seg], ax mov [dos_block_sel], dx shl bx, 4 ; paragraphs to bytes mov [dos_block_size], bx mov esi, [text_foffset] ; load text section mov edi, [dword ptr text_section + s_vaddr] mov ecx, [dword ptr text_section + s_size] call read_section mov esi, [data_foffset] ; load data section mov edi, [dword ptr data_section + s_vaddr] mov ecx, [dword ptr data_section + s_size] call read_section mov es, [client_ds] ; clear the BSS section mov edi, [dword ptr bss_section + s_vaddr] mov ecx, [dword ptr bss_section + s_size] xor eax,eax shr ecx,2 rep stos [dword ptr es:edi] mov ah,03eh mov bx, [program_file] int 021h ; close the file mov ax, 00101h mov dx, [dos_block_sel] int 031h ; free the DOS memory push [dword ptr client_cs] push [dword ptr start_eip] ; push entry address push [client_ds] mov bx,fs movzx edx,[stubinfo_ds_segment] shl edx,4 shld ecx,edx,16 mov ax,007h int 31h ; set fs to transferbuffer mov bx,ds mov ax,007h int 31h ; set ds to buffer also push fs pop es sub si,si ; offset of stubinfo in codesegment sub di,di ; transferbuffer mov cx,(stubinfo_end - stubinfo) rep movs [byte ptr es:di],[byte ptr cs:si] ; copy stubinfo structure push ds di ; little wrapper mov [dword ptr es:di], 0CD0001B8h mov [dword ptr es:di+4], 0CB661F31h mov cx,cs ; set ds to 16 bit code and cx,3 shl cx,5 or cl,9Ah mov ax,009h int 31h mov bx,cs retf ; jump to wrapper ;----------------------------------------------------------------------------- ; Read a section from the program file read_section: mov eax, esi ; sector alignment by default and eax, 01ffh add ecx, eax sub si, ax ; sector align disk offset (can't carry) sub edi, eax ; memory maybe not aligned! mov [read_size], ecx ; store for later reference mov [read_soffset], edi call zero_regs mov [word ptr dpmi_regs + dr_dx], si ; store file offset shr esi, 16 mov [word ptr dpmi_regs + dr_cx], si mov bx, [program_file] mov [word ptr dpmi_regs + dr_bx], bx mov [word ptr dpmi_regs + dr_ax], 04200h call pm_dos ; seek to start of data ; Note, handle set above mov ax, [dos_block_seg] mov [word ptr dpmi_regs + dr_ds], ax mov [word ptr dpmi_regs + dr_dx], 0 ; store file offset read_loop: mov [byte ptr dpmi_regs + dr_ah], 03fh mov ax, [word ptr read_size + 2] ; see how many bytes to read or ax, ax jnz short read_too_big mov ax, [word ptr read_size + 0] cmp ax, [dos_block_size] jna short read_size_in_ax ; jna shorter than jmp read_too_big: mov ax, [dos_block_size] read_size_in_ax: mov [word ptr dpmi_regs + dr_cx], ax call pm_dos ; read the next chunk of file data xor ecx, ecx mov cx, [word ptr dpmi_regs + dr_ax] ; get byte count mov edi, [read_soffset] ; adjust pointers add [read_soffset], ecx sub [read_size], ecx xor esi, esi ; esi=0 offset for copy data shr cx, 2 ; ecx < 64K push ds push es mov es, [client_ds] mov ds, [dos_block_sel] rep movs [dword ptr es:edi],[dword ptr ds:esi] pop es pop ds add ecx, [read_size] ; ecx zero from the rep movsd jnz read_loop ret ;----------------------------------------------------------------------------- ; Most errors come here, early ones jump direct (8088 instructions) error_no_progfile: mov dx, offset msg_no_progfile jmp short error_fn error_not_exe: mov dx, offset msg_not_exe jmp short error_fn error_not_coff: mov dx, offset msg_not_coff ; jmp error_fn error_fn: push dx mov bx, offset loadname jmp short error_in error_no_dos_memory: mov dx, offset msg_no_dos_memory jmp short error error_in_modesw: mov dx, offset msg_error_in_modesw jmp short error perror_no_selectors: mov dx, offset msg_no_selectors jmp short error perror_no_dpmi_memory: mov dx, offset msg_no_dpmi_memory jmp short error perror_no_dos_memory: mov dx, offset msg_no_dos_memory ; jmp error error: push dx mov bx, offset err_string error_in: call printstr pop bx call printstr exit: mov bx, offset crlfdollar call printstr mov ax, 04cffh ; error exit int 021h printstr1: inc bx mov ah, 2 int 021h printstr: mov dl, [bx] cmp dl, 0 jne printstr1 ret ;----------------------------------------------------------------------------- ; DPMI utility functions zero_regs: push ax push cx push di xor ax, ax mov di, offset dpmi_regs mov cx, 019h rep stosw pop di pop cx pop ax ret pm_dos: mov ax, 00300h ; simulate interrupt mov bx, 00021h ; int 21, no flags xor cx, cx ; cx = 0x0000 (copy no args) sub edi,edi mov di, offset dpmi_regs int 031h ret include_umb: cmp [dos_major], 5 ; Won't work before dos 5 jb short @f1 mov ax, 05800h ; get allocation strategy int 021h mov [old_strategy],al mov ax, 05802h ; Get UMB status. int 021h mov [old_umb],al mov ax, 05801h mov bx, 00080h ; first fit, first high then low int 021h mov ax, 05803h mov bx, 00001h ; include UMB in memory chain int 021h @f1: ret restore_umb: cmp [dos_major], 5 ; Won't work before dos 5 jb short @f2 mov ax, 05803h ; restore UMB status. mov bl,[old_umb] xor bh, bh int 021h mov ax, 05801h ; restore allocation strategy mov bl,[old_strategy] xor bh, bh int 021h @f2: ret IF EXCEPTION_HANDLER NE 0 STRUC tRegs edi dd ? esi dd ? ebp dd ? res dd ? ebx dd ? edx dd ? ecx dd ? eax dd ? flags dw ? es dw ? ds dw ? fs dw ? gs dw ? ip dw ? cs dw ? sp dw ? ss dw ? esp dd ? ; My own extensions eip dd ? eflags dd ? cr2 dd ? ENDS exception_code: count = 0 REPT 32 DB 68h DW count ; push exception number DB 0E9h DW exception_handler - 2 - $ ; jmp exception_handler count = count +1 ENDM EXCEPTION_SIZE = ($ - exception_code) / 32 MACRO CONVW dst,num mov cl,4 mov dx,num mov bx,offset dst call conv_hex ENDM MACRO CONVD dst,num mov cl,8 mov edx,num mov bx,offset dst call conv_hex ENDM public exception_vector, exception_handler exception_handler: push ds ebp mov bp,0 exception_vector = $-2 mov ds,bp mov [exp_rg.eax],eax mov [exp_rg.ebx],ebx mov [exp_rg.ecx],ecx mov [exp_rg.edx],edx mov [exp_rg.esi],esi mov [exp_rg.edi],edi mov [exp_rg.es],es mov [exp_rg.fs],fs mov [exp_rg.gs],gs mov ebp,esp mov eax,[ebp] mov [exp_rg.ebp],eax mov ax,[ebp+4] mov [exp_rg.ds],ax mov eax,[ebp+8+3*4] ; Get cs:eip mov [exp_rg.eip],eax mov ax,[ebp+8+4*4] mov [exp_rg.cs],ax mov eax,[ebp+8+5*4] mov [exp_rg.eflags],eax ; Get eflags mov eax,[ebp+8+6*4] mov [exp_rg.esp],eax mov ax,[ebp+8+7*4] mov [exp_rg.ss],ax ; Get ss:esp mov eax,cr2 mov [exp_rg.cr2],eax push ds pop es CONVW exctype,[ebp+6] CONVW excerr,[ebp+8+2*4] CONVD exceax,[exp_rg.eax] CONVD excebx,[exp_rg.ebx] CONVD excecx,[exp_rg.ecx] CONVD excedx,[exp_rg.edx] CONVD excesi,[exp_rg.esi] CONVD excedi,[exp_rg.edi] CONVD excebp,[exp_rg.ebp] CONVW excds,[exp_rg.ds] CONVW exces,[exp_rg.es] CONVW excfs,[exp_rg.fs] CONVW excgs,[exp_rg.gs] CONVW exccs,[exp_rg.cs] CONVD exceip,[exp_rg.eip] CONVD excflgs,[exp_rg.eflags] CONVW excss,[exp_rg.ss] CONVD excesp,[exp_rg.esp] CONVD exccr2,[exp_rg.cr2] mov bx,offset excerror call printstr mov ax,04CFFh int 21h ; terminate ; in: es:bx = stringbuffer, cl = # of digits, edx = number ; out: ax,bx,cl,edx = trashed conv_hex: push si shl cl,2 ror edx,cl shr cl,2 @@ll: rol edx,4 ; get digit mov si,15 and si,dx ; mask out mov al,[hexbuffer + si] mov [es:bx],al ; store converted digit inc bx dec cl jne @@ll pop si ret ENDIF ENDS ;***************************************************************************** ; Data SEGMENT _DATA PUBLIC USE16 'DATA' IF EXCEPTION_HANDLER NE 0 align 4 ; Align ourselves to a paragraph exp_rg tRegs ? hexbuffer db '0123456789ABCDEF' label excerror byte db 'exception #' exctype db 'xxxx occured with error code ' excerr db 'xxxx',13,10 db 'eax=' exceax db 'xxxxxxxx ebx=' excebx db 'xxxxxxxx ecx=' excecx db 'xxxxxxxx edx=' excedx db 'xxxxxxxx',13,10,'esi=' excesi db 'xxxxxxxx edi=' excedi db 'xxxxxxxx ebp=' excebp db 'xxxxxxxx',13,10 db 'ds=' excds db 'xxxx es=' exces db 'xxxx fs=' excfs db 'xxxx gs=' excgs db 'xxxx',13,10 db 'cs:eip=' exccs db 'xxxx:' exceip db 'xxxxxxxx eflags=' excflgs db 'xxxxxxxx ss:esp=' excss db 'xxxx:' excesp db 'xxxxxxxx cr2=' exccr2 db 'xxxxxxxx',13,10 db 0 align 4 ENDIF ;----------------------------------------------------------------------------- ; Stored Data err_string db "Load error: ",0 msg_no_progfile db ": cannot open",0 msg_not_exe db ": not EXE",0 msg_not_coff db ": not COFF",0 msg_no_dpmi db "no DPMI",0 msg_no_dos_memory db "no DOS memory",0 msg_bad_dos db "need DOS 3",0 msg_error_in_modesw db "can't switch mode",0 msg_no_selectors db "no DPMI selectors",0 msg_no_dpmi_memory db "no DPMI memory",0 crlfdollar db 13,10,0 label last_generated_byte byte ; data after this isn't in file. ENDS ;----------------------------------------------------------------------------- ; Unstored Data, available during and after mode switch SEGMENT _BSS PUBLIC USE16 'BSS' modesw_mem dw ? ; amount of memory DPMI needs program_file dw ? ; file ID of program data text_foffset dd ? ; offset in file data_foffset dd ? ; offset in file start_eip dd ? ; EIP value to start at client_cs dw ? ; must follow start_eip client_ds dw ? client_memory dd ? dos_block_seg dw ? dos_block_sel dw ? dos_block_size dw ? read_soffset dd ? read_size dd ? dos_major db ? old_umb db ? old_strategy db ? ALIGN 2 dpmi_regs db 32h dup (?) dr_edi = 000h dr_di = 000h dr_esi = 004h dr_si = 004h dr_ebp = 008h dr_bp = 008h dr_ebx = 010h dr_bx = 010h dr_bl = 010h dr_bh = 011h dr_edx = 014h dr_dx = 014h dr_dl = 014h dr_dh = 015h dr_ecx = 018h dr_cx = 018h dr_cl = 018h dr_ch = 019h dr_eax = 01ch dr_ax = 01ch dr_al = 01ch dr_ah = 01dh dr_efl = 020h dr_es = 022h dr_ds = 024h dr_fs = 026h dr_gs = 028h dr_ip = 02ah dr_cs = 02ch dr_sp = 02eh dr_ss = 030h ;----------------------------------------------------------------------------- ; At one time real mode only data. Header stuff now used during image load. loadname db 81 dup (?) ; name of program file to load, if it ; gets really long ok to overwrite next label exe_header byte ; loaded from front of loadfile exe_magic dw ? exe_bytes_last_page dw ? exe_sectors dw ? exe_header_length = $ - exe_header coff_offset dd ? ; from start of file coff_header db 20 dup (?) ; loaded from after stub aout_header db 28 dup (?) text_section db 40 dup (?) data_section db 40 dup (?) bss_section db 40 dup (?) coff_header_length = $ - coff_header ENDS SEGMENT _STACK STACK 'STACK' db stack_sz dup (?) ENDS END start