xref: /minix3/sys/arch/i386/stand/lib/biosgetrtc.S (revision 58a2b0008e28f606a7f7f5faaeaba4faac57a1ea)
1*58a2b000SEvgeniy Ivanov/*	$NetBSD: biosgetrtc.S,v 1.7 2011/06/16 13:27:59 joerg Exp $	*/
2*58a2b000SEvgeniy Ivanov
3*58a2b000SEvgeniy Ivanov/*
4*58a2b000SEvgeniy Ivanov * Copyright (c) 1996
5*58a2b000SEvgeniy Ivanov *	Matthias Drochner.  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 *
16*58a2b000SEvgeniy Ivanov * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17*58a2b000SEvgeniy Ivanov * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18*58a2b000SEvgeniy Ivanov * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19*58a2b000SEvgeniy Ivanov * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20*58a2b000SEvgeniy Ivanov * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21*58a2b000SEvgeniy Ivanov * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22*58a2b000SEvgeniy Ivanov * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23*58a2b000SEvgeniy Ivanov * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24*58a2b000SEvgeniy Ivanov * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25*58a2b000SEvgeniy Ivanov * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26*58a2b000SEvgeniy Ivanov *
27*58a2b000SEvgeniy Ivanov */
28*58a2b000SEvgeniy Ivanov
29*58a2b000SEvgeniy Ivanov#include <machine/asm.h>
30*58a2b000SEvgeniy Ivanov
31*58a2b000SEvgeniy IvanovENTRY(biosgetrtc)
32*58a2b000SEvgeniy Ivanov	pusha
33*58a2b000SEvgeniy Ivanov	pushl	%eax
34*58a2b000SEvgeniy Ivanov
35*58a2b000SEvgeniy Ivanov	xorl	%ebx, %ebx
36*58a2b000SEvgeniy Ivanov
37*58a2b000SEvgeniy Ivanov	call	_C_LABEL(prot_to_real)	# enter real mode
38*58a2b000SEvgeniy Ivanov	.code16
39*58a2b000SEvgeniy Ivanov
40*58a2b000SEvgeniy Ivanov	movb	$2, %ah
41*58a2b000SEvgeniy Ivanov	int	$0x1a
42*58a2b000SEvgeniy Ivanov	jnc	ok
43*58a2b000SEvgeniy Ivanov	movl	$-1, %ebx
44*58a2b000SEvgeniy Ivanov
45*58a2b000SEvgeniy Ivanovok:
46*58a2b000SEvgeniy Ivanov	calll	_C_LABEL(real_to_prot) # back to protected mode
47*58a2b000SEvgeniy Ivanov	.code32
48*58a2b000SEvgeniy Ivanov
49*58a2b000SEvgeniy Ivanov	popl	%eax
50*58a2b000SEvgeniy Ivanov	movb	%ch, (%eax)
51*58a2b000SEvgeniy Ivanov	movb	%cl, 1(%eax)
52*58a2b000SEvgeniy Ivanov	movb	%dh, 2(%eax)
53*58a2b000SEvgeniy Ivanov	movb	$0,  3(%eax)
54*58a2b000SEvgeniy Ivanov
55*58a2b000SEvgeniy Ivanov	movl	%ebx, 28(%esp)
56*58a2b000SEvgeniy Ivanov
57*58a2b000SEvgeniy Ivanov	popa
58*58a2b000SEvgeniy Ivanov	ret
59