Fully synchronize sys/boot from FreeBSD-5.x, but add / to the module path
[dragonfly.git] / sys / boot / pc98 / libpc98 / biosmem.c
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1/*-
2 * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
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26 * $FreeBSD: src/sys/boot/pc98/libpc98/biosmem.c,v 1.6 2003/09/08 09:11:20 obrien Exp $
27 * $DragonFly: src/sys/boot/pc98/libpc98/Attic/biosmem.c,v 1.3 2003/11/10 06:08:39 dillon Exp $
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28 */
29
30/*
31 * Obtain memory configuration information from the BIOS
32 */
33#include <stand.h>
34#include "libi386.h"
35#include "btxv86.h"
36
37vm_offset_t memtop;
38u_int32_t bios_basemem, bios_extmem;
39
40#ifndef PC98
41#define SMAPSIG 0x534D4150
42
43struct smap {
44 u_int64_t base;
45 u_int64_t length;
46 u_int32_t type;
5ee58eed 47} __packed;
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48
49static struct smap smap;
50#endif
51
52void
53bios_getmem(void)
54{
55
56#ifdef PC98
57 bios_basemem = ((*(u_char *)PTOV(0xA1501) & 0x07) + 1) * 128 * 1024;
58 bios_extmem = *(u_char *)PTOV(0xA1401) * 128 * 1024 +
59 *(u_int16_t *)PTOV(0xA1594) * 1024 * 1024;
60#else
61 /* Parse system memory map */
62 v86.ebx = 0;
63 do {
64 v86.ctl = V86_FLAGS;
65 v86.addr = 0x15; /* int 0x15 function 0xe820*/
66 v86.eax = 0xe820;
67 v86.ecx = sizeof(struct smap);
68 v86.edx = SMAPSIG;
69 v86.es = VTOPSEG(&smap);
70 v86.edi = VTOPOFF(&smap);
71 v86int();
72 if ((v86.efl & 1) || (v86.eax != SMAPSIG))
73 break;
74 /* look for a low-memory segment that's large enough */
75 if ((smap.type == 1) && (smap.base == 0) && (smap.length >= (512 * 1024)))
76 bios_basemem = smap.length;
77 /* look for the first segment in 'extended' memory */
78 if ((smap.type == 1) && (smap.base == 0x100000)) {
79 bios_extmem = smap.length;
80 }
81 } while (v86.ebx != 0);
82
83 /* Fall back to the old compatibility function for base memory */
84 if (bios_basemem == 0) {
85 v86.ctl = 0;
86 v86.addr = 0x12; /* int 0x12 */
87 v86int();
88
89 bios_basemem = (v86.eax & 0xffff) * 1024;
90 }
91
92 /* Fall back through several compatibility functions for extended memory */
93 if (bios_extmem == 0) {
94 v86.ctl = V86_FLAGS;
95 v86.addr = 0x15; /* int 0x15 function 0xe801*/
96 v86.eax = 0xe801;
97 v86int();
98 if (!(v86.efl & 1)) {
99 bios_extmem = ((v86.ecx & 0xffff) + ((v86.edx & 0xffff) * 64)) * 1024;
100 }
101 }
102 if (bios_extmem == 0) {
103 v86.ctl = 0;
104 v86.addr = 0x15; /* int 0x15 function 0x88*/
105 v86.eax = 0x8800;
106 v86int();
107 bios_extmem = (v86.eax & 0xffff) * 1024;
108 }
109#endif
110
111 /* Set memtop to actual top of memory */
112 memtop = 0x100000 + bios_extmem;
113
114}
115