FreeDOS/kernel/execrh.asm
2002-01-23 22:29:41 +00:00

107 lines
3.0 KiB
NASM

;
; File:
; execrh.asm
; Description:
; request handler for calling device drivers
;
; Copyright (c) 1995, 1998
; Pasquale J. Villani
; All Rights Reserved
;
; This file is part of DOS-C.
;
; DOS-C is free software; you can redistribute it and/or
; modify it under the terms of the GNU General Public License
; as published by the Free Software Foundation; either version
; 2, or (at your option) any later version.
;
; DOS-C is distributed in the hope that it will be useful, but
; WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
; the GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public
; License along with DOS-C; see the file COPYING. If not,
; write to the Free Software Foundation, 675 Mass Ave,
; Cambridge, MA 02139, USA.
;
; $Id$
;
%include "segs.inc"
segment HMA_TEXT
; _execrh
; Execute Device Request
;
; execrh(rhp, dhp)
; request far *rhp;
; struct dhdr far *dhp;
;
;
; The stack is very critical in here.
;
global _execrh
_execrh:
push bp ; perform c entry
mov bp,sp
push si
push ds ; sp=bp-8
lds si,[bp+8] ; ds:si = device header
les bx,[bp+4] ; es:bx = request header
mov ax, [si+6] ; construct strategy address
mov [bp+8], ax
call far[bp+8] ; call far the strategy
mov ax,[si+8] ; construct 'interrupt' address
mov [bp+8],ax ; construct interrupt address
call far[bp+8] ; call far the interrupt
sti ; damm driver turn off ints
cld ; has gone backwards
pop ds
pop si
pop bp
ret
; Log: execrh.asm,v
; Revision 1.3 2000/03/09 06:07:11 kernel
; 2017f updates by James Tabor
;
; Revision 1.2 1999/08/10 17:57:12 jprice
; ror4 2011-02 patch
;
; Revision 1.1.1.1 1999/03/29 15:40:54 jprice
; New version without IPL.SYS
;
; Revision 1.4 1999/02/08 05:55:57 jprice
; Added Pat's 1937 kernel patches
;
; Revision 1.3 1999/02/01 01:48:41 jprice
; Clean up; Now you can use hex numbers in config.sys. added config.sys screen function to change screen mode (28 or 43/50 lines)
;
; Revision 1.2 1999/01/22 04:13:25 jprice
; Formating
;
; Revision 1.1.1.1 1999/01/20 05:51:01 jprice
; Imported sources
;
;
; Rev 1.3 06 Dec 1998 8:45:06 patv
;Bug fixes.
;
; Rev 1.2 29 May 1996 21:03:30 patv
;bug fixes for v0.91a
;
; Rev 1.1 01 Sep 1995 17:54:22 patv
;First GPL release.
;
; Rev 1.0 02 Jul 1995 9:05:34 patv
;Initial revision.
; EndLog
;