ProfitPress Mega CDROM2 Shareware Freeware (MSDOS)(1992)(Eng)

home *** CD-ROM | disk | FTP | other *** search

/ ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng) / ProfitPress-MegaCDROM2.B6I / UTILITY / SYSTEM / XSPAWN34.ZIP / XSPAWN.ASM < prev next >

Wrap

Assembly Source File | 1991-05-04 | 50.4 KB | 1,394 lines

; ; XSPAWN ; Version 1.33 ; (C) Copyright 1990 Whitney Software, Inc. ; All Rights Reserved ; ; If you have increased the file handle table size so that more than 20 files ; may be open in the parent process, set FHTSZ to the new size. FHTSZ EQU 20 IFDEF LCODE ARG_1 EQU 6 ELSE ARG_1 EQU 4 ENDIF arena struc ; arena header sig db 0 ; 'M' or 'Z' if last block own dw 0 ; PSP of owner or 0 if free siz dw 0 ; size not including header arena ends vector struc number db 0 ; vector number flag db 0 ; 0-CURRENT,1-IRET,2-free,3-end vseg dw 0 ; vector segment voff dw 0 ; vector offset vector ends _TEXT SEGMENT word public 'CODE' ASSUME cs:_TEXT ASSUME ds:nothing ASSUME es:nothing ASSUME ss:nothing ; The code between slidetop and slidebot constitutes the XSPAWN kernel. The ; kernel is copied to the front of the parent process immediately following the ; parent's PSP. The environment passed to the child is copied to immediately ; following the kernel. slidetop: path db 'XSPAWN - (C) Copyright 1990 Whitney Software, Inc.' db ' All Rights Reserved' db 9 dup (0) ; 79 bytes total command db 128 dup (0) ; command-line file db 79 dup (0) ; swap file parmblk label byte ; parameter block environ dw 0 ; environment block cmd dw 0,0 ; command-line tail fcb1 dw 0,0 ; first file control block fcb2 dw 0,0 ; second file control block fcb5c db 10h dup (0) ; first file control block fcb6c db 10h dup (0) ; second file control block cntsvl dw 0 ; count save low cntsvh dw 0 ; count save high tmpcode dw 0 ; temporary return code env dw 0 ; environment segment envlen dw 0 ; environment length parsz dw 0 ; parent size ttlsz dw 0 ; total size oldsz dw 0 ; old size newsz dw 0 ; new size emsseg dw 0 ; EMS page frame segment handle dw 0 ; EMS handle useems db 0 ; if 0, use EMS save db 4 dup (0) ; save 4 bytes at DS:[2Eh] f1add dd 0 ; fnish1 address last db 0 ; if 0, last block swap IF FHTSZ - 20 fhtsv db FHTSZ dup (0) ; file handle table save ENDIF errmsg db 'XSPAWN error',0Dh,0Ah msglen EQU $-errmsg EVEN lclstk dw 64 dup (0) ; local stack stktop label word ; stack top slide1: mov ax,cs ; install local stack cli mov ss,ax mov sp,offset stktop - offset slidetop + 100h sti ; copy environment mov bx,offset slidebot - offset slidetop + 15 + 100h mov cl,4 shr bx,cl ; convert to paragraphs add bx,ax ; add CS (actually PSP) index = offset environ - offset slidetop + 100h mov cs:[index],bx ; parameter block mov es,bx xor di,di index = offset env - offset slidetop + 100h mov ds,cs:[index] xor si,si index = offset envlen - offset slidetop + 100h mov cx,cs:[index] shr cx,1 ; translate to word count rep movsw ; CF set if one byte left over adc cx,cx ; CX = 1 or 0, depending CF rep movsb ; possible final byte dec ax ; PSP segment mov es,ax ; program arena header mov bx,es:[siz] index = offset oldsz - offset slidetop + 100h mov cs:[index],bx ; old size mov byte ptr es:[sig],'M' ; not last index = offset newsz - offset slidetop + 100h mov bx,cs:[index] ; new size mov es:[siz],bx inc ax ; PSP segment add ax,bx ; add new size mov es,ax ; new last arena header mov byte ptr es:[sig],'Z' ; last index = offset last - offset slidetop + 100h cmp byte ptr cs:[index],0 je slide2 ; jump if last block swap mov byte ptr es:[sig],'M' ; not last slide2: mov word ptr es:[own],0 ; free index = offset ttlsz - offset slidetop + 100h mov ax,cs:[index] ; total size sub ax,bx ; subtract new size dec ax ; account for arena header mov es:[siz],ax ; save 4 bytes destroyed by DOS 2.0 at DS:2Eh mov ax,cs ; PSP segment mov es,ax mov bx,es:[2Eh] index = offset save - offset slidetop + 100h mov cs:[index],bx mov bx,es:[30h] index = offset save - offset slidetop + 102h mov cs:[index],bx mov bx,offset parmblk - offset slidetop + 100h mov ds,ax ; PSP segment mov dx,100h ; offset path mov ax,4B00h ; load and execute program int 21h jnc slide3 ; jump if no error index = offset tmpcode - offset slidetop + 100h mov cs:[index],ax ; temporary return code slide3: mov ax,cs ; install local stack cli mov ss,ax mov sp,offset stktop - offset slidetop + 100h sti ; restore 4 bytes destroyed by DOS 2.0 at DS:2Eh mov es,ax ; PSP segment index = offset save - offset slidetop + 100h mov bx,cs:[index] mov es:[2Eh],bx index = offset save - offset slidetop + 102h mov bx,cs:[index] mov es:[30h],bx index = offset oldsz - offset slidetop + 100h mov bx,cs:[index] ; old size mov ah,4Ah ; resize memory block int 21h jnc slide7 index = offset useems - offset slidetop + 100h slide4: cmp byte ptr cs:[index],0 jne slide6 ; jump if don't use EMS index = offset handle - offset slidetop + 100h mov dx,cs:[index] ; EMS handle slide5: mov ah,45h ; release handle and memory int 67h cmp ah,82h ; memory manager busy? je slide5 ; jump if busy slide6: jmp slide18 ; exit index = offset parsz - offset slidetop + 100h slide7: mov bx,cs:[index] ; parent size index = offset ttlsz - offset slidetop + 100h mov ax,cs:[index] ; total size sub ax,bx ; subtract parent size or ax,ax jz slide9 mov dx,cs ; PSP segment add dx,bx ; add parent size mov es,dx ; new last arena header mov byte ptr es:[sig],'Z' ; last index = offset last - offset slidetop + 100h cmp byte ptr cs:[index],0 je slide8 ; jump if last block swap mov byte ptr es:[sig],'M' ; not last slide8: mov word ptr es:[own],0 ; free dec ax ; account for arena header mov es:[siz],ax slide9: push cs ; PSP segment index = offset useems - offset slidetop + 100h cmp byte ptr cs:[index],0 jne slide14 ; jump if don't use EMS pop es ; PSP segment mov di,offset slidebot - offset slidetop + 100h index = offset emsseg - offset slidetop + 100h mov ds,cs:[index] ; EMS page frame segment mov si,offset slidebot - offset slidetop index = offset handle - offset slidetop + 100h mov dx,cs:[index] ; EMS handle xor bx,bx ; logical page number mov cx,16384 - ( offset slidebot - offset slidetop ) jmp short slide13 index = offset cntsvl - offset slidetop + 100h slide10: sub cs:[index],cx index = offset cntsvh - offset slidetop + 100h sbb word ptr cs:[index],0 xor al,al ; physical page number slide11: mov ah,44h ; map memory int 67h or ah,ah jz slide12 cmp ah,82h ; memory manager busy? je slide11 ; jump if busy jmp slide4 ; exit slide12: shr cx,1 ; translate to word count rep movsw ; CF set if one byte left over adc cx,cx ; CX = 1 or 0, depending CF rep movsb ; possible final byte xor si,si mov cx,16384 ; assume copy full block inc bx ; logical page number cmp bx,1 je slide13 mov ax,es add ax,1024 ; 16384 bytes mov es,ax mov di,16640 ; 16384 + 100h index = offset cntsvh - offset slidetop + 100h slide13: cmp word ptr cs:[index],0 jne slide10 ; jump if more than full block index = offset cntsvl - offset slidetop + 100h cmp cs:[index],cx jae slide10 ; jump if at least full block mov cx,cs:[index] ; CX = cntsvl cmp cx,0 jne slide10 ; jump if more left to copy jmp short slide17 slide14: pop ds ; PSP segment IF FHTSZ - 20 ; restore the file handle table from the kernel mov si,offset fhtsv - offset slidetop + 100h mov es,ds:[36h] ; file handle table segment mov di,ds:[34h] ; file handle table offset mov cx,FHTSZ ; file handle table size rep movsb ENDIF mov dx,offset file - offset slidetop + 100h mov ax,3D00h ; open file read only int 21h jc slide18 ; exit if error mov bx,ax ; handle xor cx,cx mov dx,offset slidebot - offset slidetop mov ax,4200h ; move file pointer int 21h ; from beginning of file mov dx,offset slidebot - offset slidetop + 100h mov cx,65520 ; assume read full block jmp short slide16 index = offset cntsvl - offset slidetop + 100h slide15: sub cs:[index],cx index = offset cntsvh - offset slidetop + 100h sbb word ptr cs:[index],0 mov ah,3Fh ; read file int 21h jc slide18 ; exit if error cmp ax,cx jne slide18 ; exit if not all read mov ax,ds add ax,4095 ; 65520 bytes mov ds,ax index = offset cntsvh - offset slidetop + 100h slide16: cmp word ptr cs:[index],0 jne slide15 ; jump if more than full block index = offset cntsvl - offset slidetop + 100h cmp word ptr cs:[index],65520 jae slide15 ; jump if at least full block mov cx,cs:[index] ; CX = cntsvl cmp cx,0 jne slide15 ; jump if more left to read index = offset tmpcode - offset slidetop + 100h slide17: mov ax,cs:[index] ; temporary return code index = offset f1add - offset slidetop + 100h jmp dword ptr cs:[index] slide18: push cs ; PSP segment pop ds mov dx,offset errmsg - offset slidetop + 100h mov cx,msglen ; errmsg length mov bx,2 ; standard error device handle mov ah,40h ; write error message int 21h mov ax,4C01h ; terminate with return code int 21h handler: iret ; interrupt handler slidebot: cntl dw 0 ; count low cnth dw 0 ; count high stks dw 0 ; original SS contents stkp dw 0 ; original SP contents psp dw 0 ; PSP segment s1add dd 0 ; slide1 address rcode dw 0 ; return code useems2 db 0 ; if 0, use EMS vtabseg dw 0 ; vectab1 segment vtaboff dw 0 ; vectab1 offset errmsg2 db 'XSPAWN error',0Dh,0Ah msglen2 EQU $-errmsg2 ; ; int _xspawn( char *, char *, char *, VECTOR *, int, int, char *, int ); ; PUBLIC __xspawn IFDEF LCODE __xspawn PROC far ELSE __xspawn PROC near ENDIF push bp mov bp,sp push di ; preserve register variables push si push ds IFDEF LDATA lds si,dword ptr [bp+ARG_1] ELSE mov si,word ptr [bp+ARG_1] ENDIF mov di,offset path start1: mov al,ds:[si] ; copy path string mov cs:[di],al ; to code segment inc si inc di or al,al ; null char? jnz start1 ; no, get next char IFDEF LDATA lds si,dword ptr [bp+ARG_1+4] ELSE mov si,word ptr [bp+ARG_1+2] ENDIF mov bx,si ; preserve si mov di,offset command mov cx,2 ; account for count and '\r' add cl,byte ptr ds:[bx] ; add count byte start2: mov al,ds:[bx] ; copy command mov cs:[di],al ; to code segment inc bx inc di loop start2 ; get next char inc si ; skip count byte push cs pop es mov di,offset fcb5c mov ax,2901h ; parse filename int 21h ; skip leading separators mov di,offset fcb6c mov al,1 ; parse filename int 21h ; skip leading separators IFDEF LDATA mov ax,word ptr [bp+ARG_1+8] ELSE mov ax,word ptr [bp+ARG_1+4] ENDIF mov cl,4 shr ax,cl ; convert to paragraphs IFDEF LDATA mov bx,word ptr [bp+ARG_1+10] ELSE mov bx,ds ENDIF add ax,bx mov cs:[env],ax ; environment segment IFDEF LDATA lds bx,dword ptr [bp+ARG_1+12] ; vectab1 ELSE mov bx,word ptr [bp+ARG_1+6] ; vectab1 ENDIF mov cs:[vtabseg],ds ; vectab1 segment mov cs:[vtaboff],bx ; vectab1 offset mov cs:[stks],ss ; original SS contents mov cs:[stkp],sp ; original SP contents mov cs:[rcode],0 ; assume success IFDEF LDATA mov ax,word ptr [bp+ARG_1+16] ELSE mov ax,word ptr [bp+ARG_1+8] ENDIF or ax,ax ; do swap? jz start3 ; yes, jump jmp noswap1 IFDEF LDATA start3: mov ax,word ptr [bp+ARG_1+18] ELSE start3: mov ax,word ptr [bp+ARG_1+10] ENDIF mov cs:[envlen],ax ; environment length add ax,offset slidebot - offset slidetop + 30 + 100h mov cl,4 shr ax,cl ; convert to paragraphs mov cs:[newsz],ax ; new size IFDEF LDATA lds si,dword ptr [bp+ARG_1+20] ELSE mov si,word ptr [bp+ARG_1+12] ENDIF mov di,offset file mov cs:[useems2],1 ; assume don't use EMS cmp byte ptr ds:[si],0 jne start4 mov cs:[useems2],0 ; use EMS start4: mov al,ds:[si] ; copy file string mov cs:[di],al ; to code segment inc si inc di or al,al ; null char? jnz start4 ; no, get next char ; save fnish1 address mov word ptr cs:[f1add+2],cs mov word ptr cs:[f1add],offset fnish1 ; initialize parameter block mov ax,cs:[psp] ; PSP segment mov cs:[cmd],offset command - offset slidetop + 100h mov cs:[cmd+2],ax mov cs:[fcb1],offset fcb5c - offset slidetop + 100h mov cs:[fcb1+2],ax mov cs:[fcb2],offset fcb6c - offset slidetop + 100h mov cs:[fcb2+2],ax cld ; left to right direction mov ds,ax ; PSP segment IFDEF LDATA mov dx,word ptr [bp+ARG_1+24] ELSE mov dx,word ptr [bp+ARG_1+14] ENDIF IF FHTSZ - 20 cmp word ptr ds:[32h],FHTSZ ; file handle table size je start5 ; jump if OK mov cs:[rcode],5 jmp short start6 ENDIF start5: mov ax,cs:[newsz] ; new size cmp ax,cs:[ttlsz] ; new size < total size? jb start8 ; yes, jump mov cs:[rcode],7 ; extremely unlikely start6: cmp cs:[useems2],0 jne start7 ; jump if don't use EMS jmp fnish2 start7: mov bx,dx ; file handle jmp fnish6 start8: cmp cs:[useems2],0 jne start12 ; jump if don't use EMS mov cs:[useems],0 ; use EMS mov cs:[handle],dx ; EMS handle mov es,cs:[emsseg] ; EMS page frame segment xor bx,bx ; logical page number jmp short start11 start9: sub cs:[cntl],cx sbb cs:[cnth],0 call mapems or ah,ah jz start10 ; jump if map succeeded jmp fnish2 start10: mov si,100h xor di,di shr cx,1 ; translate to word count rep movsw ; CF set if one byte left over adc cx,cx ; CX = 1 or 0, depending CF rep movsb ; possible final byte inc bx ; logical page number mov ax,ds add ax,1024 ; 16384 bytes mov ds,ax start11: mov cx,16384 ; assume copy full block cmp cs:[cnth],0 jne start9 ; jump if more than full block cmp cs:[cntl],16384 jae start9 ; jump if at least full block mov cx,cs:[cntl] cmp cx,0 jne start9 ; jump if more left to copy jmp short start17 start12: mov cs:[useems],1 ; don't use EMS mov bx,dx ; handle mov dx,100h ; DS:DX segment:offset buffer mov cx,65520 ; assume write full block jmp short start16 start13: sub cs:[cntl],cx sbb cs:[cnth],0 mov ah,40h ; write file int 21h jc start14 ; jump if error cmp ax,cx je start15 ; jump if all written start14: mov ah,3Eh ; close file int 21h mov cs:[rcode],5 jmp fnish7 start15: mov ax,ds add ax,4095 ; 65520 bytes mov ds,ax start16: cmp cs:[cnth],0 jne start13 ; jump if more than full block cmp cs:[cntl],65520 jae start13 ; jump if at least full block mov cx,cs:[cntl] cmp cx,0 jne start13 ; jump if more left to write mov ah,3Eh ; close file int 21h IF FHTSZ - 20 ; save the file handle table in the kernel mov es,cs:[psp] ; PSP segment mov ds,es:[36h] ; file handle table segment mov si,es:[34h] ; file handle table offset push cs pop es mov di,offset fhtsv ; file handle table save mov cx,FHTSZ ; file handle table size rep movsb ENDIF start17: mov cx,cs mov dx,offset handler ; interrupt handler offset call safevect ; set vectors in vectab1 ; time to copy the kernel mov es,cs:[psp] ; PSP segment mov di,100h mov ds,cx ; DS = CS mov si,offset slidetop mov cx,offset slidebot - offset slidetop shr cx,1 ; translate to word count rep movsw ; CF set if one byte left over adc cx,cx ; CX = 1 or 0, depending CF rep movsb ; possible final byte mov word ptr cs:[s1add+2],es ; PSP segment index = offset slide1 - offset slidetop + 100h mov word ptr cs:[s1add],index ; slide1 offset mov cx,es ; PSP segment index = offset handler - offset slidetop + 100h mov dx,index ; interrupt handler offset call safevect ; set vectors in vectab1 jmp dword ptr cs:[s1add] ; jump to the kernel ; If all goes well, this is where we come back to from the kernel. fnish1: mov cs:[rcode],ax ; return code cli ; restore original stack mov ss,cs:[stks] mov sp,cs:[stkp] sti push ds ; maybe EMS page frame segment push dx ; maybe EMS handle push bx ; maybe swap file handle mov cx,cs mov dx,offset handler ; interrupt handler offset call safevect ; set vectors in vectab1 pop bx pop dx pop ds cmp cs:[useems2],0 jne fnish4 ; jump if don't use EMS ; DS = EMS page frame segment ; DX = EMS handle mov cx,offset slidebot - offset slidetop mov es,cs:[psp] ; PSP segment mov di,100h xor si,si xor bx,bx ; logical page number call mapems or ah,ah jnz fnish3 ; jump if map failed shr cx,1 ; translate to word count rep movsw ; CF set if one byte left over adc cx,cx ; CX = 1 or 0, depending CF rep movsb ; possible final byte fnish2: mov ah,45h ; release handle and memory int 67h cmp ah,82h ; memory manager busy? je fnish2 ; jump if busy jmp short fnish7 fnish3: mov ah,45h ; release handle and memory int 67h cmp ah,82h ; memory manager busy? je fnish3 ; jump if busy jmp short fnish5 ; exit ; BX = swap file handle fnish4: xor cx,cx ; offset 0 xor dx,dx ; offset 0 mov ax,4200h ; move file pointer int 21h ; from beginning of file mov cx,offset slidebot - offset slidetop mov ds,cs:[psp] ; PSP segment mov dx,100h mov ah,3Fh ; read file int 21h jc fnish5 ; exit if error cmp ax,cx je fnish6 fnish5: push cs pop ds mov dx,offset errmsg2 mov cx,msglen2 ; errmsg2 length mov bx,2 ; standard error device handle mov ah,40h ; write error message int 21h mov ax,4C01h ; terminate with return code int 21h fnish6: mov ah,3Eh ; close file int 21h push cs pop ds mov dx,offset file mov ah,41h ; delete file int 21h fnish7: pop ds pop si ; restore register variables pop di pop bp mov ax,cs:[rcode] ; return code or ax,ax jz fnish11 push ax mov ax,3000h ; get DOS version number int 21h cmp al,3 ; major version number pop ax jb fnish8 cmp al,34 ; unknown error - 3.0 jae fnish9 cmp al,32 ; sharing violation jb fnish8 mov al,5 ; access denied jmp short fnish10 fnish8: cmp al,19 ; unknown error - 2.0 jbe fnish10 fnish9: mov al,19 ; unknown error - 2.0 fnish10: xor ah,ah fnish11: ret ; If we are not swapping, we jump here. noswap1: mov ax,cs ; initialize parameter block mov bx,cs:[env] mov cs:[environ],bx mov cs:[cmd],offset command mov cs:[cmd+2],ax mov cs:[fcb1],offset fcb5c mov cs:[fcb1+2],ax mov cs:[fcb2],offset fcb6c mov cs:[fcb2+2],ax ; save 4 bytes destroyed by DOS 2.0 at DS:2Eh mov si,cs:[2Eh] mov word ptr cs:[save],si mov si,cs:[30h] mov word ptr cs:[save+2],si mov cx,cs mov dx,offset handler ; interrupt handler offset call safevect ; set vectors in vectab1 mov es,cx ; ES = CS mov bx,offset parmblk mov ds,cx ; DS = CS mov dx,offset path mov ax,4B00h ; load and execute program int 21h jnc noswap2 ; jump if no error mov cs:[rcode],ax ; return code noswap2: cli ; restore original stack mov ss,cs:[stks] mov sp,cs:[stkp] sti ; restore 4 bytes destroyed by DOS 2.0 at DS:2Eh mov si,word ptr cs:[save] mov cs:[2Eh],si mov si,word ptr cs:[save+2] mov cs:[30h],si jmp fnish7 __xspawn ENDP mapems PROC near ; DX = handle ; BX = logical page number xor al,al ; physical page number map1: mov ah,44h ; map memory int 67h cmp ah,82h ; memory manager busy? je map1 ; jump if busy ret mapems ENDP setvectsub PROC near ; ES = vector table segment ; BX = vector table offset mov ah,25h ; set interrupt vector setvectsub1: mov al,es:[bx+flag] ; 0-CURRENT,1-IRET,2-free,3-end cmp al,3 ; is it the end? je setvectsub3 ; yes, jump cmp al,2 ; is it free? je setvectsub2 ; yes, jump mov al,es:[bx+number] ; vector number mov ds,es:[bx+vseg] ; vector segment mov dx,es:[bx+voff] ; vector offset int 21h ; set interrupt vector setvectsub2: add bx,6 ; size of vector structure jmp setvectsub1 ; next setvectsub3: ret setvectsub ENDP safevect PROC near ; CX = handler segment ; DX = handler offset mov es,cs:[vtabseg] ; vectab1 segment mov bx,cs:[vtaboff] ; vectab1 offset safevect1: mov al,es:[bx+flag] ; 0-CURRENT,1-IRET,2-free,3-end cmp al,3 ; is it the end? je safevect3 ; yes, jump cmp al,1 ; is it IRET? jne safevect2 ; no, jump mov es:[bx+vseg],cx ; handler segment mov es:[bx+voff],dx ; handler offset safevect2: add bx,6 ; size of vector structure jmp safevect1 ; next safevect3: mov bx,cs:[vtaboff] ; vectab1 offset call setvectsub ret safevect ENDP ; ; int _xsize( unsigned int, long *, long * ); ; PUBLIC __xsize IFDEF LCODE __xsize PROC far ELSE __xsize PROC near ENDIF push bp mov bp,sp push di ; preserve register variables push si push ds mov cs:[last],0 ; assume last block swap mov bx,word ptr [bp+ARG_1] ; PSP segment mov cs:[psp],bx mov dx,bx dec bx ; program arena header size1: mov es,bx ; current arena header mov ax,es:[own] or ax,ax ; is it free? jz size2 ; yes, count it cmp ax,dx ; do we own it? jne size4 ; no, jump mov cx,bx ; last owned block size2: inc bx add bx,es:[siz] ; block size jc size3 ; carry, arena is trashed mov al,es:[sig] ; get arena signature cmp al,'M' ; are we at end of memory? je size1 ; no, jump cmp al,'Z' je size5 size3: mov bx,-1 ; request maximum memory mov ah,48h ; allocate memory block int 21h mov cs:[rcode],7 jmp fnish7 size4: mov cs:[last],1 ; not last block swap size5: sub bx,dx ; subtract PSP segment mov ax,cx ; last owned block mov es,cx inc ax add ax,es:[siz] ; block size sub ax,dx ; subtract PSP segment mov cs:[parsz],ax ; parent size sub ax,10h ; subtract PSP size xor dx,dx ; convert to bytes mov cx,4 size6: shl ax,1 rcl dx,1 loop size6 IFDEF LDATA lds si,dword ptr [bp+ARG_1+2] ELSE mov si,word ptr [bp+ARG_1+2] ENDIF mov ds:[si],ax ; swap size requirement mov ds:[si+2],dx mov cs:[cntl],ax ; count low mov cs:[cnth],dx ; count high mov cx,offset slidebot - offset slidetop sub ax,cx sbb dx,0 mov cs:[cntsvl],ax ; count save low mov cs:[cntsvh],dx ; count save high mov cs:[ttlsz],bx ; total size xor dx,dx ; convert to bytes mov cx,4 size7: shl bx,1 rcl dx,1 loop size7 IFDEF LDATA lds si,dword ptr [bp+ARG_1+6] ELSE mov si,word ptr [bp+ARG_1+4] ENDIF mov ds:[si],bx ; parent and free memory mov ds:[si+2],dx pop ds pop si ; restore register variables pop di pop bp xor ax,ax ret __xsize ENDP ; ; int _chkems( char *, int * ); ; PUBLIC __chkems IFDEF LCODE __chkems PROC far ELSE __chkems PROC near ENDIF push bp mov bp,sp ; determine whether expanded memory is available IFDEF LDATA push ds lds dx,dword ptr [bp+ARG_1] ; EMM device driver name ELSE mov dx,word ptr [bp+ARG_1] ; EMM device driver name ENDIF mov ax,3D00h ; open file read only int 21h IFDEF LDATA pop ds ENDIF jc check2 ; expanded memory unavailable ; determine whether we opened the EMM device driver or a file mov bx,ax ; handle mov ax,4400h ; IOCTL - get device info int 21h jc check1 ; expanded memory unavailable test dx,80h ; test bit 7 jz check1 ; expanded memory unavailable mov ax,4407h ; IOCTL - get output status int 21h jc check1 ; expanded memory unavailable or al,al jz check1 ; expanded memory unavailable ; close EMM device driver to reclaim handle mov ah,3Eh ; close file int 21h ; determine whether the EMM is functional mov ah,40h ; get manager status int 67h or ah,ah jnz check2 ; expanded memory unavailable ; check EMM version mov ah,46h ; get EMM version int 67h or ah,ah jnz check2 ; expanded memory unavailable cmp al,32h ; version 3.2 jb check2 ; expanded memory unavailable ; get page frame segment mov ah,41h ; get page frame segment int 67h or ah,ah jnz check2 ; expanded memory unavailable mov cs:[emsseg],bx ; segment ; get size of page map information mov ax,4E03h ; get size of page map info int 67h or ah,ah jnz check2 ; expanded memory unavailable IFDEF LDATA les bx,dword ptr [bp+ARG_1+4] ; mapsize address mov es:[bx],ax ELSE mov bx,word ptr [bp+ARG_1+2] ; mapsize address mov ds:[bx],ax ENDIF xor ax,ax ; expanded memory available pop bp ret ; close EMM device driver or file to reclaim handle check1: mov ah,3Eh ; close file int 21h check2: mov ax,1 ; expanded memory unavailable pop bp ret __chkems ENDP ; ; int _savemap( char * ); ; PUBLIC __savemap IFDEF LCODE __savemap PROC far ELSE __savemap PROC near ENDIF push bp mov bp,sp push di ; preserve register variable IFDEF LDATA les di,dword ptr [bp+ARG_1] ; buffer address ELSE mov di,word ptr [bp+ARG_1] ; buffer address push ds pop es ENDIF mov ax,4E00h ; save page map int 67h pop di ; restore register variable pop bp ret __savemap ENDP ; ; int _restmap( char * ); ; PUBLIC __restmap IFDEF LCODE __restmap PROC far ELSE __restmap PROC near ENDIF push bp mov bp,sp push ds push si ; preserve register variable IFDEF LDATA lds si,dword ptr [bp+ARG_1] ; buffer address ELSE mov si,word ptr [bp+ARG_1] ; buffer address ENDIF mov ax,4E01h ; restore page map int 67h xor al,al pop si ; restore register variable pop ds pop bp ret __restmap ENDP ; ; int _getems( int, int * ); ; PUBLIC __getems IFDEF LCODE __getems PROC far ELSE __getems PROC near ENDIF push bp mov bp,sp mov bx,word ptr [bp+ARG_1] ; number of pages mov ah,43h ; get handle and allocate ; memory int 67h IFDEF LDATA les bx,dword ptr [bp+ARG_1+2] ; handle address mov es:[bx],dx ; handle ELSE mov bx,word ptr [bp+ARG_1+2] ; handle address mov ds:[bx],dx ; handle ENDIF xor al,al pop bp ret __getems ENDP ; ; int _dskspace( int, unsigned int *, unsigned int * ); ; PUBLIC __dskspace IFDEF LCODE __dskspace PROC far ELSE __dskspace PROC near ENDIF push bp mov bp,sp push di ; preserve register variable mov ah,36h ; get free disk space mov dl,byte ptr [bp+ARG_1] ; drive code (0=default, 1=A) int 21h cmp ax,0FFFFh ; was drive invalid? je space1 ; yes, jump mul cx ; bytes per sector * ; sectors per cluster IFDEF LDATA les di,dword ptr [bp+ARG_1+2] mov es:[di],ax ; bytes per cluster ELSE mov di,word ptr [bp+ARG_1+2] mov ds:[di],ax ; bytes per cluster ENDIF IFDEF LDATA les di,dword ptr [bp+ARG_1+6] mov es:[di],bx ; number of available clusters ELSE mov di,word ptr [bp+ARG_1+4] mov ds:[di],bx ; number of available clusters ENDIF xor ax,ax space1: pop di ; restore register variable pop bp ret __dskspace ENDP ; ; int _getrc( void ); ; PUBLIC __getrc IFDEF LCODE __getrc PROC far ELSE __getrc PROC near ENDIF mov ah,4Dh ; get child return code int 21h ret __getrc ENDP ; ; int _create( char *, int * ); ; PUBLIC __create IFDEF LCODE __create PROC far ELSE __create PROC near ENDIF push bp mov bp,sp IFDEF LDATA push ds ENDIF mov ax,3000h ; get DOS version number int 21h IFDEF LDATA lds dx,dword ptr [bp+ARG_1] ; file ELSE mov dx,word ptr [bp+ARG_1] ; file ENDIF xor cx,cx ; normal attribute mov ah,5Bh ; create new file cmp al,3 ; major version number jae create1 mov ah,3Ch ; create file create1: int 21h jc create2 IFDEF LDATA lds bx,dword ptr [bp+ARG_1+4] ; handle address ELSE mov bx,word ptr [bp+ARG_1+2] ; handle address ENDIF mov ds:[bx],ax xor ax,ax create2: IFDEF LDATA pop ds ENDIF pop bp ret __create ENDP ; ; int _getcd( int, char * ); ; PUBLIC __getcd IFDEF LCODE __getcd PROC far ELSE __getcd PROC near ENDIF push bp mov bp,sp push si ; preserve register variable IFDEF LDATA push ds ENDIF mov dl,byte ptr [bp+ARG_1] ; drive code (0=default, 1=A) IFDEF LDATA lds si,dword ptr [bp+ARG_1+2] ; buffer ELSE mov si,word ptr [bp+ARG_1+2] ; buffer ENDIF mov ah,47h ; get current directory int 21h jc getcd1 xor ax,ax getcd1: IFDEF LDATA pop ds ENDIF pop si ; restore register variable pop bp ret __getcd ENDP ; ; int _getdrv( void ); ; PUBLIC __getdrv IFDEF LCODE __getdrv PROC far ELSE __getdrv PROC near ENDIF mov ah,19h ; get default disk drive int 21h xor ah,ah ; AX = drive (0 = A, 1 = B, etc.) ret __getdrv ENDP ; ; void _getvect( int, unsigned int *, unsigned int * ); ; PUBLIC __getvect IFDEF LCODE __getvect PROC far ELSE __getvect PROC near ENDIF push bp mov bp,sp push ds push si ; preserve register variable mov ah,35h ; get interrupt vector mov al,byte ptr [bp+ARG_1] ; interrupt number int 21h IFDEF LDATA lds si,dword ptr [bp+ARG_1+2] ELSE mov si,word ptr [bp+ARG_1+2] ENDIF mov ds:[si],es ; segment IFDEF LDATA lds si,dword ptr [bp+ARG_1+6] ELSE mov si,word ptr [bp+ARG_1+4] ENDIF mov ds:[si],bx ; offset pop si ; restore register variable pop ds pop bp ret __getvect ENDP ; ; void _setvect( VECTOR * ); ; PUBLIC __setvect IFDEF LCODE __setvect PROC far ELSE __setvect PROC near ENDIF push bp mov bp,sp push ds ; modified in setvectsub IFDEF LDATA les bx,dword ptr [bp+ARG_1] ; vector table ELSE mov bx,word ptr [bp+ARG_1] ; vector table push ds pop es ENDIF call setvectsub pop ds pop bp ret __setvect ENDP _TEXT ENDS END