mbr.c revision 263653 
1/*-
2 * Copyright (c) 2014 Juniper Networks, Inc.
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: user/marcel/mkimg/mbr.c 263653 2014-03-23 01:10:05Z marcel $");
29
30#include <sys/types.h>
31#include <sys/diskmbr.h>
32#include <sys/endian.h>
33#include <sys/errno.h>
34#include <stdlib.h>
35#include <string.h>
36#include <unistd.h>
37
38#include "mkimg.h"
39#include "scheme.h"
40
41static struct mkimg_alias mbr_aliases[] = {
42    {	ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
43    {	ALIAS_NONE, 0 }		/* Keep last! */
44};
45
46static u_int
47mbr_metadata(u_int where)
48{
49	u_int secs;
50
51	secs = (where == SCHEME_META_IMG_START) ? 1 : 0;
52	return (secs);
53}
54
55static int
56mbr_write(int fd, lba_t imgsz __unused, void *bootcode)
57{
58	u_char *mbr;
59	struct dos_partition *dpbase, *dp;
60	struct part *part;
61	int error;
62
63	mbr = malloc(secsz);
64	if (mbr == NULL)
65		return (ENOMEM);
66	if (bootcode != NULL) {
67		memcpy(mbr, bootcode, DOSPARTOFF);
68		memset(mbr + DOSPARTOFF, 0, secsz - DOSPARTOFF);
69	} else
70		memset(mbr, 0, secsz);
71	dpbase = (void *)(mbr + DOSPARTOFF);
72	STAILQ_FOREACH(part, &partlist, link) {
73		dp = dpbase + part->index;
74		dp->dp_flag = (part->index == 0 && bootcode != NULL) ? 0x80 : 0;
75		dp->dp_shd = dp->dp_ssect = dp->dp_scyl = 0xff;	/* XXX */
76		dp->dp_typ = ALIAS_TYPE2INT(part->type);
77		dp->dp_ehd = dp->dp_esect = dp->dp_ecyl = 0xff;	/* XXX */
78		le32enc(&dp[part->index].dp_start, part->block);
79		le32enc(&dp[part->index].dp_size, part->size);
80	}
81	error = mkimg_seek(fd, 0);
82	if (error == 0) {
83		if (write(fd, mbr, secsz) != secsz)
84			error = errno;
85	}
86	free(mbr);
87	return (error);
88}
89
90static struct mkimg_scheme mbr_scheme = {
91	.name = "mbr",
92	.description = "Master Boot Record",
93	.aliases = mbr_aliases,
94	.metadata = mbr_metadata,
95	.write = mbr_write,
96	.bootcode = 512,
97	.nparts = NDOSPART
98};
99
100SCHEME_DEFINE(mbr_scheme);
101