ack/plat/msdos386/libsys/sys_exists.s

#
! $Source$
! $State$
! $Revision$

#include "libsysasm.h"

! Say whether a file exists with the given name.

.define __sys_exists
__sys_exists:
	mov eax, 4(esp)
	call .sys_scpyout
	jc 9f
	xchg edx, eax
	mov eax, 0x4300
	call .sys_dpmidos
9:
	sbb eax, eax
	inc eax
	ret
Cut-and-paste the msdos86 libsys so the msdos386 stuff now at least builds. 2022-08-07 20:10:08 +00:00			`#`
			`! $Source$`
			`! $State$`
			`! $Revision$`

plat/msdos386: refactor, firm up, and optimize - refactor code for transfer buffer reads/writes, real mode int 0x21 calls, and assembler segment declarations - define transfer buffer size in one place - beef up error checking for transfer buffer operations (prevent buffer overflows) - also optimize such operations to transfer dword by dword where feasible 2022-08-26 17:20:56 +00:00			`#include "libsysasm.h"`
Cut-and-paste the msdos86 libsys so the msdos386 stuff now at least builds. 2022-08-07 20:10:08 +00:00
			`! Say whether a file exists with the given name.`

			`.define __sys_exists`
			`__sys_exists:`
plat/msdos386: refactor, firm up, and optimize - refactor code for transfer buffer reads/writes, real mode int 0x21 calls, and assembler segment declarations - define transfer buffer size in one place - beef up error checking for transfer buffer operations (prevent buffer overflows) - also optimize such operations to transfer dword by dword where feasible 2022-08-26 17:20:56 +00:00			`mov eax, 4(esp)`
			`call .sys_scpyout`
			`jc 9f`
			`xchg edx, eax`
Most of read and write now works; filename-based operations partially work; but there's a nasty memory corruption somewhere which needs investigating. 2022-08-18 22:08:57 +00:00			`mov eax, 0x4300`
plat/msdos386: refactor, firm up, and optimize - refactor code for transfer buffer reads/writes, real mode int 0x21 calls, and assembler segment declarations - define transfer buffer size in one place - beef up error checking for transfer buffer operations (prevent buffer overflows) - also optimize such operations to transfer dword by dword where feasible 2022-08-26 17:20:56 +00:00			`call .sys_dpmidos`
			`9:`
Most of read and write now works; filename-based operations partially work; but there's a nasty memory corruption somewhere which needs investigating. 2022-08-18 22:08:57 +00:00			`sbb eax, eax`
			`inc eax`
Cut-and-paste the msdos86 libsys so the msdos386 stuff now at least builds. 2022-08-07 20:10:08 +00:00			`ret`