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("$FreeBSD$");
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_FAT16B
43#define	DOSPTYP_FAT16B	0x06
44#endif
45#ifndef DOSPTYP_FAT32
46#define	DOSPTYP_FAT32	0x0b
47#endif
48
49static struct mkimg_alias ebr_aliases[] = {
50    {	ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16B) },
51    {	ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
52    {	ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
53    {	ALIAS_NONE, 0 }
54};
55
56static lba_t
57ebr_metadata(u_int where, lba_t blk)
58{
59
60	blk += (where == SCHEME_META_PART_BEFORE) ? 1 : 0;
61	return (round_track(blk));
62}
63
64static void
65ebr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba)
66{
67	u_int cyl, hd, sec;
68
69	mkimg_chs(lba, 1023, &cyl, &hd, &sec);
70	*cylp = cyl;
71	*hdp = hd;
72	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
73}
74
75static int
76ebr_write(lba_t imgsz __unused, void *bootcode __unused)
77{
78	u_char *ebr;
79	struct dos_partition *dp;
80	struct part *part, *next;
81	lba_t block, size;
82	int error;
83
84	ebr = malloc(secsz);
85	if (ebr == NULL)
86		return (ENOMEM);
87	memset(ebr, 0, secsz);
88	le16enc(ebr + DOSMAGICOFFSET, DOSMAGIC);
89
90	error = 0;
91	STAILQ_FOREACH_SAFE(part, &partlist, link, next) {
92		block = part->block - nsecs;
93		size = round_track(part->size);
94		dp = (void *)(ebr + DOSPARTOFF);
95		ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect, nsecs);
96		dp->dp_typ = ALIAS_TYPE2INT(part->type);
97		ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
98		    part->block + size - 1);
99		le32enc(&dp->dp_start, nsecs);
100		le32enc(&dp->dp_size, size);
101
102		/* Add link entry */
103		if (next != NULL) {
104			size = round_track(next->size);
105			dp++;
106			ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
107			    next->block - nsecs);
108			dp->dp_typ = DOSPTYP_EXT;
109			ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
110			    next->block + size - 1);
111			le32enc(&dp->dp_start, next->block - nsecs);
112			le32enc(&dp->dp_size, size + nsecs);
113		}
114
115		error = image_write(block, ebr, 1);
116		if (error)
117			break;
118
119		memset(ebr + DOSPARTOFF, 0, 2 * DOSPARTSIZE);
120	}
121
122	free(ebr);
123	return (error);
124}
125
126static struct mkimg_scheme ebr_scheme = {
127	.name = "ebr",
128	.description = "Extended Boot Record",
129	.aliases = ebr_aliases,
130	.metadata = ebr_metadata,
131	.write = ebr_write,
132	.nparts = 4096,
133	.maxsecsz = 4096
134};
135
136SCHEME_DEFINE(ebr_scheme);
137