biossmap.c revision 179631 
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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sys/boot/i386/libi386/biossmap.c 179631 2008-06-07 03:07:32Z jhb $");
29
30/*
31 * Obtain memory configuration information from the BIOS
32 */
33#include <stand.h>
34#include <sys/param.h>
35#include <sys/linker.h>
36#include <machine/metadata.h>
37#include <machine/pc/bios.h>
38#include "bootstrap.h"
39#include "libi386.h"
40#include "btxv86.h"
41
42static struct {
43	struct bios_smap _smap_entry;
44	char pad[8];		/* Bad BIOS writer, no cookie! */
45} smap;
46
47static struct bios_smap *smapbase;
48static int smaplen;
49
50void
51bios_getsmap(void)
52{
53	int n;
54
55	n = 0;
56	smaplen = 0;
57	/* Count up segments in system memory map */
58	v86.ebx = 0;
59	do {
60		v86.ctl = V86_FLAGS;
61		v86.addr = 0x15;		/* int 0x15 function 0xe820*/
62		v86.eax = 0xe820;
63		v86.ecx = sizeof(struct bios_smap);
64		v86.edx = SMAP_SIG;
65		v86.es = VTOPSEG(&smap);
66		v86.edi = VTOPOFF(&smap);
67		v86int();
68		if ((v86.efl & 1) || (v86.eax != SMAP_SIG))
69			break;
70		n++;
71	} while (v86.ebx != 0);
72	if (n == 0)
73		return;
74	n += 10;	/* spare room */
75	smapbase = malloc(n * sizeof(*smapbase));
76
77	/* Save system memory map */
78	v86.ebx = 0;
79	do {
80		v86.ctl = V86_FLAGS;
81		v86.addr = 0x15;		/* int 0x15 function 0xe820*/
82		v86.eax = 0xe820;
83		v86.ecx = sizeof(struct bios_smap);
84		v86.edx = SMAP_SIG;
85		v86.es = VTOPSEG(&smap);
86		v86.edi = VTOPOFF(&smap);
87		v86int();
88		bcopy(&smap, &smapbase[smaplen], sizeof(struct bios_smap));
89		smaplen++;
90		if ((v86.efl & 1) || (v86.eax != SMAP_SIG))
91			break;
92	} while (v86.ebx != 0 && smaplen < n);
93}
94
95void
96bios_addsmapdata(struct preloaded_file *kfp)
97{
98	int len;
99
100	if (smapbase == 0 || smaplen == 0)
101		return;
102	len = smaplen * sizeof(*smapbase);
103	file_addmetadata(kfp, MODINFOMD_SMAP, len, smapbase);
104}
105
106COMMAND_SET(smap, "smap", "show BIOS SMAP", command_smap);
107
108static int
109command_smap(int argc, char *argv[])
110{
111	int i;
112
113	if (smapbase == 0 || smaplen == 0)
114		return (CMD_ERROR);
115	for (i = 0; i < smaplen; i++)
116		printf("SMAP type=%02x base=%016llx len=%016llx\n",
117		    smapbase[i].type, smapbase[i].base, smapbase[i].length);
118	return (CMD_OK);
119}
120