xref: /netbsd-src/sys/arch/i386/stand/lib/biosmemx.S (revision 2dd295436a0082eb4f8d294f4aa73c223413d0f2)
1/*	$NetBSD: biosmemx.S,v 1.11 2021/08/02 12:56:23 andvar 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/*
34 * int getextmem2(int buffer[2])
35 *
36 * return: 0=OK, -1=error
37 * buffer[0]: extmem kBytes below 16M (max 15M/1024)
38 * buffer[1]: extmem above 16M, in 64k units
39 */
40ENTRY(getextmem2)
41	pushl	%ebp
42	movl	%esp,%ebp
43	pushl	%ebx
44	pushl	%ecx
45	pushl	%edx
46	push	%esi
47	push	%edi
48
49	call	_C_LABEL(prot_to_real)
50	.code16
51
52	xorl	%ebx,%ebx
53	movl	$0xe801,%eax
54	int	$0x15
55	pushf
56
57	movw	%si,%ax
58	orw	%si,%bx
59	jz	1f		/* if zero use configured values */
60	movw	%cx,%ax		/* k below 16M (max 0x3c00 = 15MB) */
61	movw	%dx,%bx		/* 64k above 16M */
621:
63	popf
64	setc	%bl
65
66	calll	_C_LABEL(real_to_prot)
67	.code32
68
69	movl	8(%ebp),%edi
70	xorl	%eax,%eax
71	movw	%cx,%ax
72	stosl
73	movw	%dx,%ax
74	stosl
75	movb	%bl,%al
76	cbw
77
78	pop	%edi
79	pop	%esi
80	popl	%edx
81	popl	%ecx
82	popl	%ebx
83	popl	%ebp
84	ret
85
86/*
87 * int getmementry(int *iterator, int buffer[5])
88 *
89 * return: 0=ok, else error
90 * buffer[0]: start of memory chunk
91 * buffer[2]: length (bytes)
92 * buffer[4]: type
93 */
94ENTRY(getmementry)
95	pushl	%ebp
96	movl	%esp,%ebp
97	pushl	%ebx
98	pushl	%ecx
99	pushl	%edx
100	push	%esi
101	push	%edi
102
103	movl	8(%ebp),%eax
104	movl	0(%eax),%ebx		/* index */
105	movl	$20,%ecx		/* Buffer size */
106	movl	$0x534d4150,%edx	/* "SMAP" */
107	movl	12(%ebp),%edi		/* buffer address */
108
109	call	_C_LABEL(prot_to_real)
110	.code16
111
112	push	%di
113	shrl	$4,%edi
114	mov	%ds,%ax
115	add	%di,%ax
116	mov	%ax,%es
117	pop	%di
118	and	$0xf,%di		/* buffer address now in ES:DI */
119
120	movl	$0xe820,%eax		/* Some BIOS check EAX value */
121	int	$0x15
122
123	setc	%cl
124
125	calll	_C_LABEL(real_to_prot)
126	.code32
127
128	movl	8(%ebp),%eax
129	movl	%ebx,0(%eax)		/* updated index */
130	xorl	%eax,%eax
131	movb	%cl,%al
132
133	pop	%edi
134	pop	%esi
135	popl	%edx
136	popl	%ecx
137	popl	%ebx
138	popl	%ebp
139	ret
140
141/*
142 * int biosA20(void)
143 *
144 * return: 0=ok, else error
145 */
146ENTRY(biosA20)
147	pushl	%ebp
148	movl	%esp,%ebp
149	pushl	%ebx
150	pushl	%ecx
151	pushl	%edx
152	push	%esi
153	push	%edi
154
155	call	_C_LABEL(prot_to_real)
156	.code16
157
158	movl	$0x2401,%eax
159	int	$0x15
160	setc	%cl
161
162	calll	_C_LABEL(real_to_prot)
163	.code32
164
165	movzbl	%cl,%eax
166
167	pop	%edi
168	pop	%esi
169	popl	%edx
170	popl	%ecx
171	popl	%ebx
172	popl	%ebp
173	ret
174