xref: /netbsd-src/sys/arch/i386/stand/lib/biosmemps2.S (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1/*	$NetBSD: biosmemps2.S,v 1.2 2003/02/05 21:50:25 dsl Exp $	*/
2
3/*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jaromir Dolecek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *        This product includes software developed by the NetBSD
21 *        Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#include <machine/asm.h>
40
41	.text
42
43/* int getextmemp2(void buffer)
44   call int 15 function 0xc7 - later PS/2s - RETURN MEMORY-MAP INFORMATION
45   return: 0=OK, nonzero=error
46   buffer: filled with memory-map table structure
47*/
48ENTRY(getextmemps2)
49	.code32
50	pushl	%ebp
51	movl	%esp,%ebp
52	pushl	%ebx
53	pushl	%ecx
54	pushl	%edx
55	push	%esi
56	push	%edi
57
58	movl	8(%ebp), %edx	# parameter
59
60	call	_C_LABEL(prot_to_real)
61	.code16
62
63	# do int15, function 0xc0 call to discover if C7h is supported
64	movb	$0xc0, %ah
65	int	$0x15
66	setc	%bl
67	jc	out		# 0xc0 not supported if carry set
68
69	# check feature byte 2, bit 4 to see if return memory map is supported
70	movb	%es:6(%bx), %al
71	andb	$0x10, %al
72	jnz	getmem		# 0xc7 supported
73
74	# set %bl to indicate failure, and exit
75	movb	$2, %bl
76	jmp	out
77
78getmem:
79	# move the parameter to right register
80	movl	%edx, %esi
81	andl	$0xf, %esi
82	shrl	$4, %edx
83	mov	%ds, %ax
84	add	%dx, %ax
85	mov	%ax, %ds
86
87	# actually call int15, function 0xc7 now
88	movb	$0xc7, %ah
89	int	$0x15
90	setc	%bl		# save carry
91
92out:
93	calll	_C_LABEL(real_to_prot)
94	.code32
95
96	xorl	%eax, %eax
97	movb	%bl, %al	# return value in %ax
98
99	pop	%edi
100	pop	%esi
101	popl	%edx
102	popl	%ecx
103	popl	%ebx
104	popl	%ebp
105	ret
106