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/errno.h>
31#include <stdint.h>
32#include <stdlib.h>
33#include <string.h>
34
35#include <mbr.h>
36
37#include "endian.h"
38#include "image.h"
39#include "mkimg.h"
40#include "scheme.h"
41
42static struct mkimg_alias ebr_aliases[] = {
43    {	ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16) },
44    {	ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
45    {	ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
46    {	ALIAS_NONE, 0 }
47};
48
49static lba_t
50ebr_metadata(u_int where, lba_t blk)
51{
52
53	blk += (where == SCHEME_META_PART_BEFORE) ? 1 : 0;
54	return (round_track(blk));
55}
56
57static void
58ebr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba)
59{
60	u_int cyl, hd, sec;
61
62	mkimg_chs(lba, 1023, &cyl, &hd, &sec);
63	*cylp = cyl;
64	*hdp = hd;
65	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
66}
67
68static int
69ebr_write(lba_t imgsz __unused, void *bootcode __unused)
70{
71	u_char *ebr;
72	struct dos_partition *dp;
73	struct part *part, *next;
74	lba_t block, size;
75	int error;
76
77	ebr = malloc(secsz);
78	if (ebr == NULL)
79		return (ENOMEM);
80	memset(ebr, 0, secsz);
81	le16enc(ebr + DOSMAGICOFFSET, DOSMAGIC);
82
83	error = 0;
84	TAILQ_FOREACH(part, &partlist, link) {
85		block = part->block - nsecs;
86		size = round_track(part->size);
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 + size - 1);
92		le32enc(&dp->dp_start, nsecs);
93		le32enc(&dp->dp_size, size);
94
95		/* Add link entry */
96		next = TAILQ_NEXT(part, link);
97		if (next != NULL) {
98			size = round_track(next->size);
99			dp++;
100			ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
101			    next->block - nsecs);
102			dp->dp_typ = DOSPTYP_EXT;
103			ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
104			    next->block + size - 1);
105			le32enc(&dp->dp_start, next->block - nsecs);
106			le32enc(&dp->dp_size, size + nsecs);
107		}
108
109		error = image_write(block, ebr, 1);
110		if (error)
111			break;
112
113		memset(ebr + DOSPARTOFF, 0, 2 * DOSPARTSIZE);
114	}
115
116	free(ebr);
117	return (error);
118}
119
120static struct mkimg_scheme ebr_scheme = {
121	.name = "ebr",
122	.description = "Extended Boot Record",
123	.aliases = ebr_aliases,
124	.metadata = ebr_metadata,
125	.write = ebr_write,
126	.nparts = 4096,
127	.maxsecsz = 4096
128};
129
130SCHEME_DEFINE(ebr_scheme);
131