xref: /minix3/sys/arch/i386/stand/lib/biosdelay.S (revision 58a2b0008e28f606a7f7f5faaeaba4faac57a1ea)
1*58a2b000SEvgeniy Ivanov/*	$NetBSD: biosdelay.S,v 1.4 2005/12/11 12:17:48 christos Exp $	*/
2*58a2b000SEvgeniy Ivanov
3*58a2b000SEvgeniy Ivanov/*
4*58a2b000SEvgeniy Ivanov * Copyright (c) 1996, 1997
5*58a2b000SEvgeniy Ivanov * 	Perry E. Metzger.  All rights reserved.
6*58a2b000SEvgeniy Ivanov *
7*58a2b000SEvgeniy Ivanov * Redistribution and use in source and binary forms, with or without
8*58a2b000SEvgeniy Ivanov * modification, are permitted provided that the following conditions
9*58a2b000SEvgeniy Ivanov * are met:
10*58a2b000SEvgeniy Ivanov * 1. Redistributions of source code must retain the above copyright
11*58a2b000SEvgeniy Ivanov *    notice, this list of conditions and the following disclaimer.
12*58a2b000SEvgeniy Ivanov * 2. Redistributions in binary form must reproduce the above copyright
13*58a2b000SEvgeniy Ivanov *    notice, this list of conditions and the following disclaimer in the
14*58a2b000SEvgeniy Ivanov *    documentation and/or other materials provided with the distribution.
15*58a2b000SEvgeniy Ivanov * 3. All advertising materials mentioning features or use of this software
16*58a2b000SEvgeniy Ivanov *    must display the following acknowledgements:
17*58a2b000SEvgeniy Ivanov *	This product includes software developed for the NetBSD Project
18*58a2b000SEvgeniy Ivanov *	by Perry E. Metzger.
19*58a2b000SEvgeniy Ivanov * 4. The names of the authors may not be used to endorse or promote products
20*58a2b000SEvgeniy Ivanov *    derived from this software without specific prior written permission.
21*58a2b000SEvgeniy Ivanov *
22*58a2b000SEvgeniy Ivanov * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23*58a2b000SEvgeniy Ivanov * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24*58a2b000SEvgeniy Ivanov * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25*58a2b000SEvgeniy Ivanov * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26*58a2b000SEvgeniy Ivanov * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27*58a2b000SEvgeniy Ivanov * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28*58a2b000SEvgeniy Ivanov * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29*58a2b000SEvgeniy Ivanov * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30*58a2b000SEvgeniy Ivanov * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31*58a2b000SEvgeniy Ivanov * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32*58a2b000SEvgeniy Ivanov *
33*58a2b000SEvgeniy Ivanov */
34*58a2b000SEvgeniy Ivanov
35*58a2b000SEvgeniy Ivanov#include <machine/asm.h>
36*58a2b000SEvgeniy Ivanov
37*58a2b000SEvgeniy Ivanov	.text
38*58a2b000SEvgeniy Ivanov
39*58a2b000SEvgeniy Ivanov/*
40*58a2b000SEvgeniy Ivanov * BIOS call "INT 15H Function 86H" to sleep for a set number of microseconds
41*58a2b000SEvgeniy Ivanov *	Call with	%ah = 0x86
42*58a2b000SEvgeniy Ivanov *			%cx = time interval (high)
43*58a2b000SEvgeniy Ivanov *			%dx = time interval (low)
44*58a2b000SEvgeniy Ivanov *	Return:
45*58a2b000SEvgeniy Ivanov *		If error
46*58a2b000SEvgeniy Ivanov *			CF  = set
47*58a2b000SEvgeniy Ivanov *		else
48*58a2b000SEvgeniy Ivanov *			CF  = clear
49*58a2b000SEvgeniy Ivanov */
50*58a2b000SEvgeniy IvanovENTRY(delay)
51*58a2b000SEvgeniy Ivanov	pushl	%ebp
52*58a2b000SEvgeniy Ivanov	pushl	%ebx
53*58a2b000SEvgeniy Ivanov	pushl	%esi
54*58a2b000SEvgeniy Ivanov	pushl	%edi
55*58a2b000SEvgeniy Ivanov
56*58a2b000SEvgeniy Ivanov	movw	20(%esp), %dx
57*58a2b000SEvgeniy Ivanov	movw	22(%esp), %cx
58*58a2b000SEvgeniy Ivanov
59*58a2b000SEvgeniy Ivanov	call	_C_LABEL(prot_to_real)
60*58a2b000SEvgeniy Ivanov	.code16
61*58a2b000SEvgeniy Ivanov
62*58a2b000SEvgeniy Ivanov	movb	$0x86, %ah
63*58a2b000SEvgeniy Ivanov	int	$0x15
64*58a2b000SEvgeniy Ivanov	setnc	%ah
65*58a2b000SEvgeniy Ivanov
66*58a2b000SEvgeniy Ivanov	movb	%ah, %bl	# real_to_prot uses %eax
67*58a2b000SEvgeniy Ivanov
68*58a2b000SEvgeniy Ivanov	calll	_C_LABEL(real_to_prot)
69*58a2b000SEvgeniy Ivanov	.code32
70*58a2b000SEvgeniy Ivanov
71*58a2b000SEvgeniy Ivanov	xorl	%eax, %eax
72*58a2b000SEvgeniy Ivanov	movb	%bl, %al
73*58a2b000SEvgeniy Ivanov
74*58a2b000SEvgeniy Ivanov	popl	%edi
75*58a2b000SEvgeniy Ivanov	popl	%esi
76*58a2b000SEvgeniy Ivanov	popl	%ebx
77*58a2b000SEvgeniy Ivanov	popl	%ebp
78*58a2b000SEvgeniy Ivanov	ret
79