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TITLE LDHEADER - Load Exe Header procedure
.xlistinclude gpfix.incinclude kernel.incinclude newexe.inc.list
externA __AHINCR
externFP IGlobalAllocexternFP IGlobalFreeexternFP FarSetOwnerexternFP Int21HandlerexternFP FarMyUpperexternFP IsBadStringPtrexternFP _hread
DataBegin
externB fBootingexternB szBozoexternW winVerexternD pSErrProc
DataEnd externFP IGlobalLockexternFP IGlobalUnLock
sBegin NRESCODEassumes CS,NRESCODE
externNP NResGetPureName
;-----------------------------------------------------------------------;; LoadExeHeader ;; ;; Routine to read an EXE header and check for a new format EXE file. ;; Returns NULL if not a new format EXE. Otherwise reads the resident ;; portion of the new EXE header into allocated storage and returns ;; the segment address of the new EXE header. ;; ;; Arguments: ;; parmW fh ;; parmW isfh ;; parmD pfilename ;; ;; Returns: ;; AX = segment of exe header ;; DL = ne_exetyp ;; DH = ne_flagsothers ;; ;; Error Returns: ;;LME_MEM = 0 ; Out of memory ;;LME_VERS = 10 ; Wrong windows version ;;LME_INVEXE = 11 ; Invalid exe ;;LME_OS2 = 12 ; OS/2 app ;;LME_DOS4 = 13 ; DOS 4 app ;;LME_EXETYPE = 14 ; unknown exe type ;;LME_COMP = 19 ; Compressed EXE file ;;LME_PE = 21 ; Portable EXE ;; ;; Registers Preserved: ;; DI,SI ;; ;; Registers Destroyed: ;; AX,BX,CX,DS,ES ;; Calls: ;; ;; History: ;; ;; Thu Mar 19, 1987 08:35:32p -by- David N. Weise [davidw] ;; Added this nifty comment block. ;;-----------------------------------------------------------------------;
cProc LoadExeHeader,<PUBLIC,FAR>,<si,di> parmW fh parmW isfh parmD pfilename localW pnewexe localW exetype localW nchars localW pseg localW psegsrc localW hBlock localW pBlock localW NEFileOffset localD PreloadLen localW NEBase localW exeflags localW expver localW saveSP localB fast_fail ; 1 if we can't use fastload block localV hdrbuf,<SIZE EXE_HDR>
.errnz SIZE EXE_HDR - SIZE NEW_EXE
cBegin xor ax,ax mov pseg,ax mov hBlock, ax mov fast_fail, al cmp SEG_pfilename,ax je re0
IF KDEBUG ; LoadExeHeader is internal cCall IsBadStringPtr, <pfilename, 128> ; so we assume file pointer is OK or ax, ax jnz refailjENDIF lds si,pfilename mov al,ds:[si].opLen inc ax ; include null bytere0: mov nchars,ax mov bx,fh ; No, seek backwards over what cmp isfh,bx je refile mov ds,bx xor si,si jmp remem
refile: ; Here to load from a file push ss ; DS:SI points to I/O buffer pop ds lea si,hdrbuf ; Read beginning of file mov dx,si mov cx,SIZE EXE_HDR mov bx,fh mov ah,3Fh DOSFCALL jnc @Frefailj: jmps refail@@: cmp ax,cx ; Old EXE file, look for offset jb refailj ; to new exe header cmp ds:[si].e_magic,EMAGIC ; Check for old exe file je @F cmp ds:[si], 'ZS' ; Is it compressed? jne refail cmp ds:[si][2],'DD' jne refail cmp ds:[si][4],0F088h jne refail cmp ds:[si][6],03327h jne refail mov ax, LME_COMP ; Compressed EXE jmp reexit@@: mov ax,ds:[si].e_lfanew.hi mov dx,ds:[si].e_lfanew.lo mov pnewexe,dx ; To check for bound OS/2 apps. or ax,dx jz refail ; Fail if not there.
mov cx,ds:[si].e_lfanew.hi mov dx,ds:[si].e_lfanew.lo mov bx, fh mov ax,4200h DOSFCALL jc refail mov cx,SIZE NEW_EXE mov dx,si mov ah,3Fh DOSFCALL jc refail cmp ax,cx jne refail cmp ds:[si].ne_magic,NEMAGIC ; Did we get a valid new EXE header? je remem cmp ds:[si].ne_magic,PEMAGIC ; Did we find a Portable EXE (WIN32) jne refail mov ax, LME_PE jmps rejrefail: mov ax, LME_INVEXE ; invalid NEW EXE file formatrej: jmp reexit
remem: mov psegsrc,bx ; bx has either fh or seg address mov di,ds:[si].ne_enttab ; Compute size of resident new header add di,ds:[si].ne_cbenttab add di, 6 ; null entry space (bug #8414)
mov cx, ds:[si].ne_cbenttab mov bx, ds:[si].ne_cmovent shl bx, 1 sub cx, bx shl bx, 1 sub cx, bx ; Number of bytes not moveable entries shl cx, 1 ; Allow triple these bytes add di, cx
mov cx,ds:[si].ne_cseg ; + 3 * #segments
; Reserve space for ns_handle field in segment table
shl cx,1 add di,cx
.errnz 10 - SIZE NEW_SEG1
; Reserve space for file info block at end
add di,nchars ; + size of file info block
xor ax,ax ; Allocate a fixed block for header mov bx,GA_ZEROINIT or GA_MOVEABLE cCall IGlobalAlloc,<bx,ax,di> ; that isn't code or data. or ax,ax jnz @F jmps badformat@@: push ax cCall IGlobalLock,<ax> pop ax push dx cCall IGlobalUnlock,<ax> pop ax sub di,nchars mov pseg,ax mov es,ax ; ES:0 -> new header location cld ; DS:SI -> old header mov bx,psegsrc cmp isfh,bx ; Is header in memory? jne remem1 ; Yes, continue mov ax,ds:[si].ne_enttab ; No, read into high end add ax,ds:[si].ne_cbenttab ; of allocated block sub di,ax mov cx,SIZE NEW_EXE ; Copy part read so far sub ax,cx rep movsb mov cx,ax smov ds,es ; Read rest of header from file mov dx,di mov ah,3fh DOSFCALL mov bx,ax jc refail1 lea si,[di-SIZE NEW_EXE] ; DS:SI -> old header cmp bx,cx je remem1badformat: mov ax, LME_INVEXE ; don't change flagsrefail1: ; Here if error reading header push ax SetKernelDSNRes ; DS may be = pseg, prevent cCall IGlobalFree,<pseg> ; GP faults in pmode. pop ax jmp reexit
remem1: UnsetKernelDS test ds:[si].ne_flags,NEIERR ; Errors in EXE image? jnz badformat ; Yes, fail
cmp ds:[si].ne_ver,4 ; No, built by LINK4 or above? jl badformat ; No, error mov bx,ds:[si].ne_flags ; Make local copies of ne_flags & and bl,NOT NEPROT ; ne_expver which can be modified mov exeflags,bx ; (can't change ROM exe headers). mov bx,ds:[si].ne_expver mov expver,bx mov bx,word ptr ds:[si].ne_exetyp ; get exetyp and flagsothers mov exetype,bx
cmp bl,NE_UNKNOWN jz windows_exe cmp bl,NE_WINDOWS ; is it a Windows exe? jz windows_exe mov ax,LME_OS2 cmp bl,NE_OS2 ; is it an OS|2 exe? jnz not_os2 test bh,NEINPROT ; can it be run under Windows? jz @F and exeflags,NOT NEAPPLOADER or exeflags,NEPROT mov expver,0300h jmps windows_exe@@: cmp pnewexe,0800h ; is it a bound jb refail1 jmp badformatnot_os2: inc ax ; AX = 13 - LME_DOS4 cmp bl,NE_DOS4 ; is it a DOS 4 exe? jz refail1 inc ax ; AX = 14 - LME_EXETYPE jmp refail1
mgxlib DB 'MGXLIB'
windows_exe:
mov NEBase, si ; Offset of Source header xor di,di ; ES:DI -> new header location mov cx,SIZE NEW_EXE ; Copy fixed portion of header cld rep movsb mov ax,exeflags mov es:[ne_flags],ax mov ax,expver mov es:[ne_expver],ax mov si, NEBase add si, es:[ne_segtab] ; Real location of segment table mov cx,es:[ne_cseg] ; Copy segment table, adding mov es:[ne_segtab],di jcxz recopysegxrecopyseg:
movsw ; ns_sector movsw ; ns_cbseg lodsw ; ns_flags
.errnz 4 - ns_flags
and ax,not (NS286DOS XOR NSGETHIGH) ; Clear 286DOS bits; record in the segment flags if this module is a process, this is for EMS
test ax,NSTYPE ; NSCODE jnz not_code or ax,NSWINCODEnot_code: or ax,NSNOTP test es:[ne_flags],NSNOTP jnz not_a_process xor ax,NSNOTP or ax,NSMOVEnot_a_process: stosw ; ns_flags movsw ; ns_minalloc .errnz 8 - SIZE NEW_SEG xor ax,ax stosw ; one word for ns_handle field .errnz 10 - SIZE NEW_SEG1 loop recopyseg
recopysegx: test es:[ne_flagsothers], NEGANGLOAD jz no_gang_loadj mov bx, fh cmp bx, isfh jne no_gang_loadj
mov ax, es:[ne_gang_start] or ax, ax jz no_gang_loadj mov NEFileOffset, ax ; file offset of gang load area mov ax, es:[ne_gang_length] or ax, ax jz no_gang_loadj mov cx, es:[ne_align] xor dx, dxgl_len: ; find length of Gang Load area shl ax, 1 adc dx, dx loop gl_len
cmp dx, 10h ; Greater than 1Mb, forget it!! jb alloc_it ; PS: NEVER go bigger than 1Mbno_gang_loadj: jmp no_gang_load ; since LongPtrAdd is limited...
alloc_it: mov word ptr PreloadLen[0], ax mov word ptr PreloadLen[2], dx mov ch, GA_DISCARDABLE mov cl, GA_MOVEABLE+GA_NODISCARD+GA_NOCOMPACT push es cCall IGlobalAlloc,<cx,dx,ax> ; Allocate this much memory pop es or ax, ax jz no_gang_loadj mov hBlock, ax ; Have memory to read file into push es cCall IGlobalLock,<ax> pop es mov pBlock, dx mov dx, NEFileOffset mov cx, es:[ne_align] xor bx, bxgl_pos: ; find pos of Gang Load start shl dx, 1 adc bx, bx loop gl_pos
mov cx, bx
mov bx, fh mov ax,4200h DOSFCALL ; Seek to new exe header jc refailgang
mov ax, pBlock xor bx, bx farptr memadr,ax,bx cCall _hread, <fh, memadr, PreloadLen> cmp dx, word ptr PreloadLen[2] jnz refailgang cmp ax, word ptr PreloadLen[0] jz no_gang_load ; We're OK now; push ds; xor dx, dx; mov ax, pBlock
; push si; push di; mov si, word ptr PreloadLen[2]; mov di, word ptr PreloadLen[0];read_file:; mov cx, 08000h ; Must be factor 64k DON'T CHANGE THIS; or si, si; jnz big_read; cmp cx, di; jbe big_read; mov cx, di ; all that's left; jcxz done_read ; Nothing left, quit.;big_read:; mov ds, ax; mov ah, 3Fh; DOSFCALL ; Read chunk from file; jc refailgang; cmp ax, cx ; All we asked for?; jne refailgang ; no, file corrupted; sub di, cx; sbb si, 0; mov ax, ds; add dx, cx ; On to next block; jnc read_file; add ax, __AHINCR; jmps read_file;refailgang:; pop di; pop si; pop ds cCall IGlobalUnlock,<hBlock> cCall IGlobalFree,<hBlock> mov hBlock, 0 jmps no_gang_load
BadExeHeader: ; GP fault handler!!! mov sp, saveSP; fix_fault_stack jmp refail1 ; corrupt exe header (or our bug)
;done_read:; pop di; pop si; pop ds
no_gang_load: mov saveSP, spbeg_fault_trap BadExeHeader mov cx,es:[ne_restab] ; Copy resource table sub cx,es:[ne_rsrctab] mov si, NEBase ; Get correct source address add si, es:[ne_rsrctab] mov es:[ne_rsrctab],di rep movsb
rerestab: mov cx,es:[ne_modtab] ; Copy resident name table sub cx,es:[ne_restab] mov es:[ne_restab],di rep movsb
push di mov di, es:[ne_restab] ; Make the module name Upper Case xor ch, ch mov cl, es:[di] inc diuppercaseit: mov al, es:[di] call farMyUpper stosb loop uppercaseit pop di
mov cx,es:[ne_imptab] ; Copy module xref table sub cx,es:[ne_modtab] mov es:[ne_modtab],di rep movsb
mov es:[ne_psegrefbytes],di ; Insert segment reference byte table mov es:[ne_pretthunks],di ; Setup return thunks mov cx,es:[ne_enttab] ; Copy imported name table sub cx,es:[ne_imptab] mov es:[ne_imptab],di jcxz reenttab rep movsb
reenttab: mov es:[ne_enttab],di ; Scan current entry table xor ax, ax ; First entry in block mov bx, di ; Pointer to info for this block stosw ; Starts at 0 stosw ; Ends at 0 stosw ; And is not even here!
copy_next_block: lodsw ; Get # entries and type xor cx, cx mov cl, al jcxz copy_ent_done
mov al, ah cmp al, ENT_UNUSED jne copy_used_block
mov ax, es:[bx+2] ; Last entry in current block cmp ax, es:[bx] ; No current block? jne end_used_block
add es:[bx], cx add es:[bx+2], cx jmps copy_next_block
end_used_block: mov es:[bx+4], di ; Pointer to next block mov bx, di add ax, cx ; Skip unused entries stosw ; First in new block stosw ; Last in new block xor ax, ax stosw ; End of list jmps copy_next_block
copy_used_block: add es:[bx+2], cx ; Add entries in this block cmp al, ENT_MOVEABLE je copy_moveable_block
; absolutes end up here as well
copy_fixed_block: stosb ; Segno movsb ; Flag byte stosb ; segno again to match structure movsw ; Offset loop copy_fixed_block jmps copy_next_block
copy_moveable_block: stosb ; ENT_MOVEABLE movsb ; Flag byte add si, 2 ; Toss int 3Fh movsb ; Copy segment # movsw ; and offset loop copy_moveable_block jmps copy_next_block
copy_ent_done: xor bx,bx cmp es:[bx].ne_ver,5 ; Produced by version 5.0 LINK4 jae remem2a ; or above? mov es:[bx].ne_expver,bx ; No, clear uninitialized fields mov es:[bx].ne_swaparea,bx
; TEMPORARY BEGIN
push ax push cx push di push si mov si,es:[bx].ne_rsrctab cmp si,es:[bx].ne_restab jz prdone mov di,es:[si].rs_align add si,SIZE new_rsrcprtype: cmp es:[si].rt_id,0 je prdone mov cx,es:[si].rt_nres add si,SIZE rsrc_typeinfoprname: push cx mov ax,es:[si].rn_flags test ah,0F0h ; Is old discard field set? jz @F or ax,RNDISCARD ; Yes, convert to bit@@: and ax,not RNUNUSED ; Clear unused bits in 4.0 LINK files mov es:[si].rn_flags,ax pop cx add si,SIZE rsrc_nameinfo loop prname
jmp prtype
prdone: pop si pop di pop cx pop ax
; TEMPORARY END
FixFlags: ; label for debuggingpublic FixFlags, leh_slowpublic leh_code, leh_patchnext, leh_code_fixed, leh_patchdone, leh_dataremem2a: ; (bx == 0) mov es:[bx].ne_usage,bx mov es:[bx].ne_pnextexe,bx mov es:[bx].ne_pfileinfo,bx cmp es:[bx].ne_align,bx jne @F mov es:[bx].ne_align,NSALIGN@@: mov cx,nchars jcxz @F mov es:[bx].ne_pfileinfo,di lds si,pfilename rep movsb@@: ; Save pointer to seginfo record mov bx,es:[bx].ne_autodata ; of automatic data segment or bx,bx jz @F dec bx shl bx,1 mov cx,bx shl bx,1 shl bx,1 add bx,cx .errnz 10 - SIZE NEW_SEG1 add bx,es:[ne_segtab]@@: mov es:[ne_pautodata],bx
SetKernelDSNRes
; Scan seg table, marking nonautomatic DATA segments fixed, preload
mov ax,es:[ne_expver] ; Default expected version to or ax,ax jnz @F mov ax,201h mov es:[ne_expver],ax ; 2.01@@: cmp ax,winVer jbe @F cCall IGlobalFree,<pseg> mov ax, LME_VERS jmp reexit@@: mov bx,es:[ne_segtab] xor cx,cx sub bx,SIZE NEW_SEG1 jmps leh_patchnext
leh_test_preload: test byte ptr es:[bx].ns_flags, NSPRELOAD jnz leh_patchnext
or byte ptr es:[bx].ns_flags, NSPRELOAD
cmp es:[bx].ns_sector, 0 ; don't whine about empty segments je leh_patchnext
krDebugOut DEB_WARN, "Segment #CX of %ES0 must be preload" mov fast_fail, 1
leh_patchnext: add bx,SIZE NEW_SEG1 inc cx cmp cx,es:[ne_cseg] ja leh_patchdone test byte ptr es:[bx].ns_flags,NSDATA ; Is it a code segment? jz leh_code ; Yes, next segment .errnz NSCODEleh_data: ; Data must be non-discardable, preloadif KDEBUG test es:[bx].ns_flags, NSDISCARD jz @F krDebugOut DEB_WARN, "Data Segment #CX of %ES0 can't be discardable"@@:endif and es:[bx].ns_flags,not NSDISCARD ; Data segments not discardable jmps leh_test_preload
leh_code: test byte ptr es:[bx].ns_flags,NSMOVE; Moveable code? jz leh_code_fixed
; moveable code must be discardable, or must be preloadif KDEBUG test es:[ne_flags],NENOTP ; for 3.0 libraries can't have jz @F ; moveable only code cmp fBooting,0 ; If not booting jne @F test es:[bx].ns_flags,NSDISCARD jnz @F krDebugOut DEB_WARN, "Segment #CX of %ES0 was discardable under Win 3.0"@@:endif test es:[bx].ns_flags,NSDISCARD ; Is it discardable? jnz leh_patchnext jmp leh_test_preload
leh_code_fixed: ; fixed code must be preload cmp fBooting,0 ; If not booting jne leh_patchnext jmp leh_test_preload
leh_patchdone: mov bx,word ptr es:[ne_csip+2] ; Is there a start segment? or bx,bx jz @F ; No, continue dec bx shl bx,1 mov si,bx shl si,1 shl si,1 add si,bx .errnz 10 - SIZE NEW_SEG1 add si,es:[ne_segtab] ; Mark start segment as preloadif kdebug test byte ptr es:[si].ns_flags,NSPRELOAD jnz scs_pre krDebugOut DEB_WARN, "Starting Code Segment of %ES0 must be preload" mov fast_fail, 1scs_pre:endif or byte ptr es:[si].ns_flags,NSPRELOAD
cmp es:[ne_autodata],0 ; Is there a data segment? je @F or es:[si].ns_flags,NSUSESDATA ; Yes, then it needs it mov si,es:[ne_pautodata]if kdebug test byte ptr es:[si].ns_flags,NSPRELOAD jnz sds_pre cmp es:[bx].ns_sector, 0 ; don't whine about empty segments je sds_pre krDebugOut DEB_WARN, "Default Data Segment of %ES0 must be preload" mov fast_fail, 1sds_pre:endif or byte ptr es:[si].ns_flags,NSPRELOAD ; Mark DS as preload@@: test es:[ne_flags],NENOTP ; No stack if not a process jnz @F cmp es:[ne_stack],4096+1024 jae @F mov es:[ne_stack],4096+1024 ; 4k stack is not enough (raor)@@: mov cx, es:[ne_heap] ; If the module wants a heap jcxz leh_heapadjdone ; make sure it's big enough mov ax, 800h ; ; Environment variables have cmp cx, ax ; grown, so we need more heap jae leh_heapadjdone ; space for apps so we use 800h mov dx, ax test es:[ne_flags],NENOTP jnz @F add dx, es:[ne_stack] jc leh_heapadjmin @@: mov bx,es:[ne_autodata] ; set if no autodata segment or bx,bx ; we have to do this here jz leh_heapadjset ; because for certain dlls dec bx ; pautodata is not initialized shl bx,1 mov cx,bx shl bx,1 shl bx,1 add bx,cx add bx,es:[ne_segtab] add dx, es:[bx].ns_minalloc jnc leh_heapadjset leh_heapadjmin: ; if 800h is too big fallback toif KDEBUG ; what win9x code used as minimum mov ax, 100h + SIZE LocalStats ; heap size 100helse mov ax, 100h endif mov cx, es:[ne_heap] cmp cx, ax jae leh_heapadjdoneleh_heapadjset: mov es:[ne_heap], axleh_heapadjdone:
mov ax,es ; Set owner to be itself cCall FarSetOwner,<ax,ax>
mov dx,exetype test dh,NEINFONT ; save the font bit in exehdr jz reexit ; somewhere or es:[ne_flags],NEWINPROTend_fault_trap
reexit:; cmp ax, 20h ; translate error messages for ret; jae @F; mov bx, ax; xor ax, ax; cmp bl, 1 ; bx is 0, 1, 2, 19, other; jz @F ; 1 -> 0 (out of memory); mov al, 11; jb @F ; 0 -> 11 (invalid format); cmp bl, 3 ;; mov al, 10; jb @F ; 2 -> 10 (windows version); mov al, 19 ; 3 -> 19 (compressed EXE); jz @F ; others left alone; mov al, bl;@@: push dx mov bx, hBlock or bx, bx je noUnlock ; No block to unlock push ax cCall IGlobalUnlock,<bx> push ss pop ds ; might be freeing DS cmp fast_fail, 1 ; is fastload area invalid? jne @Fleh_slow: krDebugOut DEB_WARN, "FastLoad area ignored due to incorrect segment flags" cCall IGlobalFree,<hBlock> ; yes - free it, force slow-load mov hBlock, 0@@: pop ax cmp ax, LME_MAXERR jae noFree ; Success, return memory block in bx push ax cCall IGlobalFree,<hBlock> pop axnoFree: mov cx, NEFileOffset ; Return offset of header in CX mov bx, hBlocknoUnlock: pop dx UnSetKernelDScEnd
sEnd NRESCODE
end
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