saunders@hydra.unm.edu (07/10/90)
MSDOS/8086 gurus:
Thanks for the responses. Alas, most weren't what I needed. I'll come
clean right away: I am totally incompetent at 8086 assembly language! The
Novell IPX/SPX and Microsoft XMS interfaces are CALLed, but with parms in
the registers. Sort of a cross between a normal function call and a DOS
"int 21h" call. Both IPX/SPX and XMS hook into "multiplex interrupt" 2fh
and return their main address for the API (damn all these TLAs!) in ES:DI
or ES:BX. Then, Joe-Assembly-Programmer would just store the result
someplace and make indirect jumps through it. Here is an example from the
XMS docs:
mov ax,4310h ; XMS int 2fh signiture
int 2Fh
mov word ptr [XMSControl],bx ; XMSControl is a DWORD
mov word ptr [XMSControl+2],es
; We now have the XMS API entry point
; then we'de call an XMS function like this:
mov ah,00h ; function code for "Get XMS version number"
call [XMSControl]
Notice how weird that is. It's neither a int86() call nor a normal
function call. What I need is a general-purpose routine kind of like
int86x(), but I'm unable to write one. e.g.
void farcall(void far *api_entry,
union REGS regstuff,
struct SREGS sregstuff);
I hear some of the mega-optimizing compilers have ways of declaring
functions that take register parms, but I need something for MIX or MSC.
-- Rich Saundersshields@yunexus.YorkU.CA (Paul Shields) (07/11/90)
In article <1990Jul9.195959.13596@ariel.unm.edu>, saunders@hydra.unm.edu writes: > MSDOS/8086 gurus: > > Thanks for the responses. Alas, most weren't what I needed. I'll come > clean right away[...explanation deleted...] > > -- Rich Saunders Well, it took a couple hours, but here is the result that I think will work: call86() and call86x() They're analogous to the int86() and int86x() calls (which were built for microsoft C and a few other compilers.) I've tested them a little on MSC 5.1 and they seem to handle registers properly. Since I don't have the network software that Rich writes about I can't give them a throrough test. Anyway, here they are. I've increased the distribution from "na" to world since it could be useful to others, and included the .obj and .exe files as a uuencoded zip file (just for completeness.) Paul Shields shields@nccn.yorku.ca #! /bin/sh # This is a shell archive. Remove anything before this line, then unpack # it by saving it into a file and typing "sh file". To overwrite existing # files, type "sh file -c". You can also feed this as standard input via # unshar, or by typing "sh <file", e.g.. If this archive is complete, you # will see the following message at the end: # "End of shell archive." # Contents: COPYRIGHT REQUEST build.bat call86.asm call86.c call86.h # objects.z.uue test.c # Wrapped by shields@yunexus on Wed Jul 11 03:58:28 1990 PATH=/bin:/usr/bin:/usr/ucb ; export PATH if test -f 'COPYRIGHT' -a "${1}" != "-c" ; then echo shar: Will not clobber existing file \"'COPYRIGHT'\" else echo shar: Extracting \"'COPYRIGHT'\" \(483 characters\) sed "s/^X//" >'COPYRIGHT' <<'END_OF_FILE' XCopyright 1990 by Paul A. Shields. This software may be distributed Xand used in other works free of charge provided that all source code Xversions of this software and its derivatives contain this copyright Xnotice and license. As this software is distributed in source code Xform, the author shall not be held responsible for damages resulting Xfrom its use. If the software fails to perform as specified, you Xassume all costs of servicing it or repairing damages that it may Xcause. END_OF_FILE if test 483 -ne `wc -c <'COPYRIGHT'`; then echo shar: \"'COPYRIGHT'\" unpacked with wrong size! fi # end of 'COPYRIGHT' fi if test -f 'REQUEST' -a "${1}" != "-c" ; then echo shar: Will not clobber existing file \"'REQUEST'\" else echo shar: Extracting \"'REQUEST'\" \(2144 characters\) sed "s/^X//" >'REQUEST' <<'END_OF_FILE' XPath: yunexus!geac!torsqnt!news-server.csri.toronto.edu!rutgers!mephisto!ncar!unmvax!ariel.unm.edu!hydra.unm.edu!saunders XFrom: saunders@hydra.unm.edu XNewsgroups: comp.os.msdos.programmer,comp.sys.ibm.pc.programmer,alt.msdos.programmer XSubject: More "Far Call in C" XMessage-ID: <1990Jul9.195959.13596@ariel.unm.edu> XDate: 9 Jul 90 19:59:59 GMT XArticle-I.D.: ariel.1990Jul9.195959.13596 XPosted: Mon Jul 9 15:59:59 1990 XSender: usenet@ariel.unm.edu (USENET News System) XDistribution: na XOrganization: University of New Mexico, Albuquerque XLines: 32 XXref: yunexus comp.os.msdos.programmer:48 comp.sys.ibm.pc.programmer:2523 alt.msdos.programmer:1771 X X X MSDOS/8086 gurus: X X Thanks for the responses. Alas, most weren't what I needed. I'll come Xclean right away: I am totally incompetent at 8086 assembly language! The XNovell IPX/SPX and Microsoft XMS interfaces are CALLed, but with parms in Xthe registers. Sort of a cross between a normal function call and a DOS X"int 21h" call. Both IPX/SPX and XMS hook into "multiplex interrupt" 2fh Xand return their main address for the API (damn all these TLAs!) in ES:DI Xor ES:BX. Then, Joe-Assembly-Programmer would just store the result Xsomeplace and make indirect jumps through it. Here is an example from the XXMS docs: X X mov ax,4310h ; XMS int 2fh signiture X int 2Fh X mov word ptr [XMSControl],bx ; XMSControl is a DWORD X mov word ptr [XMSControl+2],es X ; We now have the XMS API entry point X ; then we'de call an XMS function like this: X mov ah,00h ; function code for "Get XMS version number" X call [XMSControl] X X Notice how weird that is. It's neither a int86() call nor a normal Xfunction call. What I need is a general-purpose routine kind of like Xint86x(), but I'm unable to write one. e.g. X void farcall(void far *api_entry, X union REGS regstuff, X struct SREGS sregstuff); X I hear some of the mega-optimizing compilers have ways of declaring Xfunctions that take register parms, but I need something for MIX or MSC. X X -- Rich Saunders X END_OF_FILE if test 2144 -ne `wc -c <'REQUEST'`; then echo shar: \"'REQUEST'\" unpacked with wrong size! fi # end of 'REQUEST' fi if test -f 'build.bat' -a "${1}" != "-c" ; then echo shar: Will not clobber existing file \"'build.bat'\" else echo shar: Extracting \"'build.bat'\" \(50 characters\) sed "s/^X//" >'build.bat' <<'END_OF_FILE' Xmasm /Ml call86.asm; Xcl -AL -Zi test.c call86.obj END_OF_FILE if test 50 -ne `wc -c <'build.bat'`; then echo shar: \"'build.bat'\" unpacked with wrong size! fi # end of 'build.bat' fi if test -f 'call86.asm' -a "${1}" != "-c" ; then echo shar: Will not clobber existing file \"'call86.asm'\" else echo shar: Extracting \"'call86.asm'\" \(2512 characters\) sed "s/^X//" >'call86.asm' <<'END_OF_FILE' X; Author: Paul A. Shields X; Hand-coded from MSC 5.1 output of call86.c stub. X; July 11, 1990 X X TITLE call86.c X NAME call86 X XCALL86_TEXT SEGMENT WORD PUBLIC 'CODE' XCALL86_TEXT ENDS X_DATA SEGMENT WORD PUBLIC 'DATA' X_DATA ENDS XCONST SEGMENT WORD PUBLIC 'CONST' XCONST ENDS X_BSS SEGMENT WORD PUBLIC 'BSS' X_BSS ENDS XDGROUP GROUP CONST, _BSS, _DATA X ASSUME CS: CALL86_TEXT, DS: DGROUP, SS: DGROUP XEXTRN __acrtused:ABS XCALL86_TEXT SEGMENT X ASSUME CS: CALL86_TEXT X; Line 24 X PUBLIC _call86 X_call86 PROC FAR X push bp X mov bp,sp X push si X; addr = 6 X; inreg = 10 X; outreg = 14 X X;inreg X les bx,DWORD PTR [bp+10] X push WORD PTR es:[bx] ; ax X mov ax,WORD PTR es:[bx+2] ; bx X mov cx,WORD PTR es:[bx+4] ; cx X mov dx,WORD PTR es:[bx+6] ; dx X mov si,WORD PTR es:[bx+8] ; si X mov di,WORD PTR es:[bx+10] ; di X mov bx,ax X pop ax X X call DWORD PTR [bp+6] ; addr X pushf X; outreg X push ax X mov ax,bx X les bx,DWORD PTR [bp+14] ;outreg X mov WORD PTR es:[bx+10],di ; di X mov WORD PTR es:[bx+8],si ; si X mov WORD PTR es:[bx+6],dx ; dx X mov WORD PTR es:[bx+4],cx ; cx X mov WORD PTR es:[bx+2],ax ; bx X pop WORD PTR es:[bx] ; ax X pop WORD PTR es:[bx+12] ; cflags X; Line 33 X pop si X pop bp X ret X nop X X_call86 ENDP X; Line 39 X PUBLIC _call86x X_call86x PROC FAR X push bp X mov bp,sp X push si X; addr = 6 X; inreg = 10 X; outreg = 14 X; segreg = 18 X X push ds ; save ds X X les bx,DWORD PTR [bp+18] ;segreg X mov ds,WORD PTR es:[bx+6] ; ds X push WORD PTR es:[bx] ; es X X les bx,DWORD PTR [bp+10] X push ax,WORD PTR es:[bx] ; ax X mov ax,WORD PTR es:[bx+2] ; bx X mov cx,WORD PTR es:[bx+4] ; cx X mov dx,WORD PTR es:[bx+6] ; dx X mov si,WORD PTR es:[bx+8] ; si X mov di,WORD PTR es:[bx+10] ; di X mov bx,ax X pop ax X pop es X X call DWORD PTR [bp+6] ; addr X pushf X push ax X mov ax,bx X X push es X les bx,DWORD PTR [bp+18] ;segreg X mov WORD PTR es:[bx+6],ds ; ds X pop WORD PTR es:[bx] ; es X X les bx,DWORD PTR [bp+14] ;outreg X mov WORD PTR es:[bx+10],di ; di X mov WORD PTR es:[bx+8],si ; si X mov WORD PTR es:[bx+6],dx ; dx X mov WORD PTR es:[bx+4],cx ; cx X mov WORD PTR es:[bx+2],ax ; bx X X pop WORD PTR es:[bx] ; ax X pop WORD PTR es:[bx+12] ; cflags X X pop ds ; restore ds X pop si X pop bp X ret X nop X X_call86x ENDP XCALL86_TEXT ENDS XEND END_OF_FILE if test 2512 -ne `wc -c <'call86.asm'`; then echo shar: \"'call86.asm'\" unpacked with wrong size! fi # end of 'call86.asm' fi if test -f 'call86.c' -a "${1}" != "-c" ; then echo shar: Will not clobber existing file \"'call86.c'\" else echo shar: Extracting \"'call86.c'\" \(1216 characters\) sed "s/^X//" >'call86.c' <<'END_OF_FILE' X/* call86.c - "stub" for calling an assembly language function from C. X X Author: Paul A. Shields X Date: July 11, 1990 X Features: Function calls were built to be analogous to X Microsoft C 5.x functions int86() and int86x(). X X **** NOTE! this file is provided for completeness only! X it is a stub which will not work as coded. X To make this work, I compiled as follows: X X cl -AL -Ox -Fa call86.c -c X X then edited the assembly output file as needed to insert X the proper code into the stubs. X */ X X#include <dos.h> X#include "call86.h" X X/* w/o setting up segment registers: */ Xint call86(void far *addr,union REGS *inreg, X union REGS *outreg) X{ X outreg->x.ax = inreg->x.ax; X outreg->x.bx = inreg->x.bx; X outreg->x.cx = inreg->x.cx; X outreg->x.dx = inreg->x.dx; X outreg->x.si = inreg->x.si; X outreg->x.di = inreg->x.di; X outreg->x.cflag = inreg->x.cflag; X X return inreg->x.ax; X} X X/* with setting up segment registers: */ Xint call86x(void far *addr,union REGS *inreg, X union REGS *outreg, struct SREGS *segreg) X{ X outreg->x.ax = segreg->es; X outreg->x.bx = segreg->cs; X outreg->x.cx = segreg->ss; X outreg->x.dx = segreg->ds; X return inreg->x.ax; X} END_OF_FILE if test 1216 -ne `wc -c <'call86.c'`; then echo shar: \"'call86.c'\" unpacked with wrong size! fi # end of 'call86.c' fi if test -f 'call86.h' -a "${1}" != "-c" ; then echo shar: Will not clobber existing file \"'call86.h'\" else echo shar: Extracting \"'call86.h'\" \(277 characters\) sed "s/^X//" >'call86.h' <<'END_OF_FILE' X/* call86.h - protoype statements for call86.c X Author: Paul A. Shields X X built to be analogous to Microsoft C 5.x functions int86() and X int86x(). 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broehl@watserv1.waterloo.edu (Bernie Roehl) (07/17/90)
In article <1990Jul9.195959.13596@ariel.unm.edu> saunders@hydra.unm.edu writes: >Here is an example from the XMS docs: > > mov ax,4310h ; XMS int 2fh signiture > int 2Fh > mov word ptr [XMSControl],bx ; XMSControl is a DWORD > mov word ptr [XMSControl+2],es > ; We now have the XMS API entry point > ; then we'de call an XMS function like this: > mov ah,00h ; function code for "Get XMS version number" > call [XMSControl] There are a couple of ways of doing this. In Turbo C 2.00: #include <dos.h> void far (*xmsfn)(); ... union REGS r; struct SREGS s; r.x.ax = 0x4310; int86x(0x2F, &r, &r, &s); xmsfn = MK_FP(s.es, r.x.bx); /* We now have the XMS API entry point */ _AX = 0; (*xmsfn)(); Note that in Turbo C (and presumably other C's), no registers are used in do the (*xmsfn)(); that line of code becomes the single instruction "call dword ptr DGROUP:_xxx" (assuming the xxx is declared globally, which it should be). Thus you can load up the _AX, _BX etc registers with whatever you like before the call, and (if you're careful) get most of them after the call. Not real elegant, but it works. The other way to do it is: #include <dos.h> void interrupt (*xmsfn)(); /* Note interrupt, not far */ int xxx = 0x??; /* pick some unused interrupt vector */ ... union REGS r; struct SREGS s; r.x.ax = 0x4310; int86x(0x2F, &r, &r, &s); xmsfn = MK_FP(s.es, r.x.bx); setvect(xxx, xmsfn); r.h.ah = 0; int86x(xxx, &r, &r, &s); The advantage to this approach is that it makes no assumptions about what code is generated by the compiler, and the technique should work similarly under any reasonable C compiler; the disadvantage is that you have to find one interrupt vector that you *know* isn't being used for anything else. (It would be very nice if there were a "standard" vector for this purpose; the best you can do is search (say, starting at 0x60 or so) for vectors pointing to an IRET instruction). -- Bernie Roehl, University of Waterloo Electrical Engineering Dept Mail: broehl@watserv1.waterloo.edu OR broehl@watserv1.UWaterloo.ca BangPath: {allegra,decvax,utzoo,clyde}!watmath!watserv1!broehl Voice: (519) 747-5056 [home] (519) 885-1211 x 2607 [work]