cb13571dab
git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@204 6ac86273-5f31-0410-b378-82cca8765d1b
138 lines
4.2 KiB
NASM
138 lines
4.2 KiB
NASM
;
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; File:
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; execrh.asm
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; Description:
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; request handler for calling device drivers
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;
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; Copyright (c) 1995, 1998
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; Pasquale J. Villani
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; All Rights Reserved
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;
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; This file is part of DOS-C.
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;
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; DOS-C is free software; you can redistribute it and/or
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; modify it under the terms of the GNU General Public License
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; as published by the Free Software Foundation; either version
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; 2, or (at your option) any later version.
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;
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; DOS-C is distributed in the hope that it will be useful, but
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; WITHOUT ANY WARRANTY; without even the implied warranty of
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; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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; the GNU General Public License for more details.
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;
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; You should have received a copy of the GNU General Public
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; License along with DOS-C; see the file COPYING. If not,
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; write to the Free Software Foundation, 675 Mass Ave,
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; Cambridge, MA 02139, USA.
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;
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; $Logfile: C:/usr/patv/dos-c/src/kernel/execrh.asv $
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;
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; $Id$
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;
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; $Log$
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; Revision 1.7 2001/04/21 22:32:53 bartoldeman
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; Init DS=Init CS, fixed stack overflow problems and misc bugs.
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;
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; Revision 1.6 2001/04/15 03:21:50 bartoldeman
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; See history.txt for the list of fixes.
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;
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; Revision 1.5 2001/04/02 23:18:30 bartoldeman
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; Misc, zero terminated device names and redirector bugs fixed.
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;
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; Revision 1.4 2001/03/21 02:56:25 bartoldeman
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; See history.txt for changes. Bug fixes and HMA support are the main ones.
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;
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; Revision 1.3 2000/05/25 20:56:21 jimtabor
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; Fixed project history
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;
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; Revision 1.2 2000/05/08 04:30:00 jimtabor
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; Update CVS to 2020
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;
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; Revision 1.1.1.1 2000/05/06 19:34:53 jhall1
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; The FreeDOS Kernel. A DOS kernel that aims to be 100% compatible with
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; MS-DOS. Distributed under the GNU GPL.
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;
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; Revision 1.3 2000/03/09 06:07:11 kernel
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; 2017f updates by James Tabor
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;
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; Revision 1.2 1999/08/10 17:57:12 jprice
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; ror4 2011-02 patch
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;
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; Revision 1.1.1.1 1999/03/29 15:40:54 jprice
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; New version without IPL.SYS
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;
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; Revision 1.4 1999/02/08 05:55:57 jprice
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; Added Pat's 1937 kernel patches
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;
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; Revision 1.3 1999/02/01 01:48:41 jprice
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; 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)
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;
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; Revision 1.2 1999/01/22 04:13:25 jprice
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; Formating
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;
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; Revision 1.1.1.1 1999/01/20 05:51:01 jprice
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; Imported sources
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;
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;
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; Rev 1.3 06 Dec 1998 8:45:06 patv
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;Bug fixes.
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;
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; Rev 1.2 29 May 1996 21:03:30 patv
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;bug fixes for v0.91a
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;
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; Rev 1.1 01 Sep 1995 17:54:22 patv
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;First GPL release.
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;
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; Rev 1.0 02 Jul 1995 9:05:34 patv
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;Initial revision.
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; $EndLog$
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;
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%include "segs.inc"
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segment HMA_TEXT
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; _execrh
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; Execute Device Request
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;
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; execrh(rhp, dhp)
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; request far *rhp;
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; struct dhdr far *dhp;
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;
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;
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; The stack is very critical in here.
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;
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global _execrh
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_execrh:
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push bp ; perform c entry
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mov bp,sp
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; push bx ; random char on display
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push si
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push es ; sometimes it get lost
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push ds ; sp=bp-8
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lds si,[bp+8] ; ds:si = device header
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les bx,[bp+4] ; es:bx = request header
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push bp
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push ds
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push si ; needed later
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mov ax, [si+6]
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mov [bp+8], ax
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call far[bp+8] ; call far the strategy
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pop si ; these were saved
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pop ds
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pop bp
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mov ax, [si+8]
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mov [bp+8], ax
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call far[bp+8] ; call far the interrupt
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sti ; damm driver turn off ints
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cld ; has gone backwards
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pop ds
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pop es
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pop si
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; pop bx
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pop bp
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ret
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