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 *
26 * $FreeBSD: src/sys/boot/i386/libi386/biossmap.c,v 1.2 2003/08/25 23:28:31 obrien Exp $
27 */
28
29 /*
30 * Obtain memory configuration information from the BIOS
31 */
32 #include <stand.h>
33 #include <sys/param.h>
34 #include <sys/linker.h>
35 #include <machine/metadata.h>
36 #include <machine/pc/bios.h>
37 #include <machine/psl.h>
38 #include "bootstrap.h"
39 #include "libi386.h"
40 #include "btxv86.h"
41
42 static struct bios_smap smap;
43
44 static struct bios_smap *smapbase;
45 static int smaplen;
46
47 void
bios_getsmap(void)48 bios_getsmap(void)
49 {
50 int n;
51
52 n = 0;
53 smaplen = 0;
54 /* Count up segments in system memory map */
55 v86.ebx = 0;
56 do {
57 v86.ctl = V86_FLAGS;
58 v86.addr = 0x15; /* int 0x15 function 0xe820*/
59 v86.eax = 0xe820;
60 v86.ecx = sizeof(struct bios_smap);
61 v86.edx = SMAP_SIG;
62 v86.es = VTOPSEG(&smap);
63 v86.edi = VTOPOFF(&smap);
64 v86int();
65 if ((v86.efl & PSL_C) || (v86.eax != SMAP_SIG))
66 break;
67 n++;
68 } while (v86.ebx != 0);
69 if (n == 0)
70 return;
71 n += 10; /* spare room */
72 smapbase = malloc(n * sizeof(*smapbase));
73
74 /* Save system memory map */
75 v86.ebx = 0;
76 do {
77 v86.ctl = V86_FLAGS;
78 v86.addr = 0x15; /* int 0x15 function 0xe820*/
79 v86.eax = 0xe820;
80 v86.ecx = sizeof(struct bios_smap);
81 v86.edx = SMAP_SIG;
82 v86.es = VTOPSEG(&smap);
83 v86.edi = VTOPOFF(&smap);
84 v86int();
85
86 /*
87 * Our heap is now in high memory and must be removed from
88 * the smap so the kernel does not blow away passed-in
89 * arguments, smap, kenv, etc.
90 *
91 * This wastes a little memory.
92 */
93 if (smap.type == SMAP_TYPE_MEMORY &&
94 smap.base + smap.length > heapbase &&
95 smap.base < memtop) {
96 if (smap.base <= heapbase) {
97 if (heapbase - smap.base) {
98 smapbase[smaplen] = smap;
99 smapbase[smaplen].length =
100 heapbase - smap.base;
101 ++smaplen;
102 }
103 }
104 if (smap.base + smap.length >= memtop) {
105 if (smap.base + smap.length - memtop) {
106 smapbase[smaplen] = smap;
107 smapbase[smaplen].base = memtop;
108 smapbase[smaplen].length =
109 smap.base + smap.length -
110 memtop;
111 ++smaplen;
112 }
113 }
114 } else {
115 smapbase[smaplen] = smap;
116 ++smaplen;
117 }
118 if ((v86.efl & PSL_C) || (v86.eax != SMAP_SIG))
119 break;
120 } while (v86.ebx != 0 && smaplen < n);
121 }
122 void
bios_addsmapdata(struct preloaded_file * kfp)123 bios_addsmapdata(struct preloaded_file *kfp)
124 {
125 int len;
126
127 if (smapbase == NULL || smaplen == 0)
128 return;
129 len = smaplen * sizeof(*smapbase);
130 file_addmetadata(kfp, MODINFOMD_SMAP, len, smapbase);
131 /* Temporary compatibility with older development kernels */
132 file_addmetadata(kfp, 0x0009, len, smapbase);
133 }
134