ebr.c revision 272030 
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: stable/10/usr.bin/mkimg/ebr.c 272030 2014-09-23 16:05:23Z 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 "image.h"
39#include "mkimg.h"
40#include "scheme.h"
41
42#ifndef DOSPTYP_FAT32
43#define	DOSPTYP_FAT32	0x0b
44#endif
45
46static struct mkimg_alias ebr_aliases[] = {
47    {	ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
48    {	ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
49    {	ALIAS_NONE, 0 }
50};
51
52static lba_t
53ebr_metadata(u_int where, lba_t blk)
54{
55
56	blk += (where == SCHEME_META_PART_BEFORE) ? 1 : 0;
57	return (round_track(blk));
58}
59
60static void
61ebr_chs(u_char *cyl, u_char *hd, u_char *sec, uint32_t lba __unused)
62{
63
64	*cyl = 0xff;		/* XXX */
65	*hd = 0xff;		/* XXX */
66	*sec = 0xff;		/* XXX */
67}
68
69static int
70ebr_write(lba_t imgsz __unused, void *bootcode __unused)
71{
72	u_char *ebr;
73	struct dos_partition *dp;
74	struct part *part, *next;
75	lba_t block;
76	int error;
77
78	ebr = malloc(secsz);
79	if (ebr == NULL)
80		return (ENOMEM);
81	memset(ebr, 0, secsz);
82	le16enc(ebr + DOSMAGICOFFSET, DOSMAGIC);
83
84	error = 0;
85	STAILQ_FOREACH_SAFE(part, &partlist, link, next) {
86		block = part->block - nsecs;
87		dp = (void *)(ebr + DOSPARTOFF);
88		ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect, nsecs);
89		dp->dp_typ = ALIAS_TYPE2INT(part->type);
90		ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
91		    part->block + part->size - 1);
92		le32enc(&dp->dp_start, nsecs);
93		le32enc(&dp->dp_size, part->size);
94
95		/* Add link entry */
96		if (next != NULL) {
97			dp++;
98			ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
99			    next->block - nsecs);
100			dp->dp_typ = DOSPTYP_EXT;
101			ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
102			    next->block + next->size - 1);
103			le32enc(&dp->dp_start, next->block - nsecs);
104			le32enc(&dp->dp_size, next->size + nsecs);
105		}
106
107		error = image_write(block, ebr, 1);
108		if (error)
109			break;
110
111		memset(ebr + DOSPARTOFF, 0, 2 * DOSPARTSIZE);
112	}
113
114	free(ebr);
115	return (error);
116}
117
118static struct mkimg_scheme ebr_scheme = {
119	.name = "ebr",
120	.description = "Extended Boot Record",
121	.aliases = ebr_aliases,
122	.metadata = ebr_metadata,
123	.write = ebr_write,
124	.nparts = 4096,
125	.maxsecsz = 4096
126};
127
128SCHEME_DEFINE(ebr_scheme);
129