xref: /minix3/sys/arch/i386/stand/lib/biosmemx.S (revision 58a2b0008e28f606a7f7f5faaeaba4faac57a1ea)
1/*	$NetBSD: biosmemx.S,v 1.9 2008/10/14 14:18:11 ad Exp $	*/
2
3/*
4 * Copyright (c) 1997, 1999
5 *	Matthias Drochner.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 */
28
29#include <machine/asm.h>
30
31	.text
32
33/* int getextmem2(int buffer[2])
34   return: 0=OK, -1=error
35   buffer[0]: extmem kBytes below 16M (max 15M/1024)
36   buffer[1]: extmem above 16M, in 64k units
37*/
38ENTRY(getextmem2)
39	pushl	%ebp
40	movl	%esp,%ebp
41	pushl	%ebx
42	pushl	%ecx
43	pushl	%edx
44	push	%esi
45	push	%edi
46
47	call	_C_LABEL(prot_to_real)
48	.code16
49
50	xorl	%ebx, %ebx
51	movl	$0xe801, %eax
52	int	$0x15
53	pushf
54
55	movw	%si, %ax
56	orw	%si, %bx
57	jz	1f		/* if zero use configured values */
58	movw	%cx, %ax	/* k below 16M (max 0x3c00 = 15MB) */
59	movw	%dx, %bx	/* 64k above 16M */
601:
61	popf
62	setc	%bl
63
64	calll	_C_LABEL(real_to_prot)
65	.code32
66
67	movl	8(%ebp), %edi
68	xorl	%eax, %eax
69	movw	%cx, %ax
70	stosl
71	movw	%dx, %ax
72	stosl
73	movb	%bl, %al
74	cbw
75
76	pop	%edi
77	pop	%esi
78	popl	%edx
79	popl	%ecx
80	popl	%ebx
81	popl	%ebp
82	ret
83
84/* int getmementry(int *iterator, buffer[5])
85   return: 0=ok, else error
86   buffer[0]: start of memory chunk
87   buffer[2]: length (bytes)
88   buffer[4]: type
89*/
90ENTRY(getmementry)
91	pushl	%ebp
92	movl	%esp,%ebp
93	pushl	%ebx
94	pushl	%ecx
95	pushl	%edx
96	push	%esi
97	push	%edi
98
99	movl	8(%ebp), %eax
100	movl	0(%eax), %ebx		/* index */
101	movl	$20, %ecx		/* Buffer size */
102	movl	$0x534d4150, %edx	/* "SMAP" */
103	movl	12(%ebp), %edi		/* buffer address */
104
105	call	_C_LABEL(prot_to_real)
106	.code16
107
108	push	%di
109	shrl	$4, %edi
110	mov	%ds, %ax
111	add	%di, %ax
112	mov	%ax, %es
113	pop	%di
114	and	$0xf, %di		/* buffer addres now in ES:DI */
115
116	movl	$0xe820, %eax		/* Some BIOS check EAX value */
117	int	$0x15
118
119	setc	%cl
120
121	calll	_C_LABEL(real_to_prot)
122	.code32
123
124	movl	8(%ebp), %eax
125	movl	%ebx, 0(%eax)		/* updated index */
126	xorl	%eax, %eax
127	movb	%cl, %al
128
129	pop	%edi
130	pop	%esi
131	popl	%edx
132	popl	%ecx
133	popl	%ebx
134	popl	%ebp
135	ret
136
137/* int biosA20(void)
138   return: 0=ok, else error
139*/
140ENTRY(biosA20)
141	pushl	%ebp
142	movl	%esp,%ebp
143	pushl	%ebx
144	pushl	%ecx
145	pushl	%edx
146	push	%esi
147	push	%edi
148
149	call	_C_LABEL(prot_to_real)
150	.code16
151
152	movl	$0x2401, %eax
153	int	$0x15
154	setc	%cl
155
156	calll	_C_LABEL(real_to_prot)
157	.code32
158
159	movzbl	%cl, %eax
160
161	pop	%edi
162	pop	%esi
163	popl	%edx
164	popl	%ecx
165	popl	%ebx
166	popl	%ebp
167	ret
168