minix/sys/arch/i386/stand/lib/biosdelay.S
2012-02-09 18:48:13 +01:00

78 lines
2.3 KiB
ArmAsm

/* $NetBSD: biosdelay.S,v 1.4 2005/12/11 12:17:48 christos Exp $ */
/*
* Copyright (c) 1996, 1997
* Perry E. Metzger. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgements:
* This product includes software developed for the NetBSD Project
* by Perry E. Metzger.
* 4. The names of the authors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <machine/asm.h>
.text
/*
* BIOS call "INT 15H Function 86H" to sleep for a set number of microseconds
* Call with %ah = 0x86
* %cx = time interval (high)
* %dx = time interval (low)
* Return:
* If error
* CF = set
* else
* CF = clear
*/
ENTRY(delay)
pushl %ebp
pushl %ebx
pushl %esi
pushl %edi
movw 20(%esp), %dx
movw 22(%esp), %cx
call _C_LABEL(prot_to_real)
.code16
movb $0x86, %ah
int $0x15
setnc %ah
movb %ah, %bl # real_to_prot uses %eax
calll _C_LABEL(real_to_prot)
.code32
xorl %eax, %eax
movb %bl, %al
popl %edi
popl %esi
popl %ebx
popl %ebp
ret