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#include <sys/errno.h>
29#include <stdint.h>
30#include <stdlib.h>
31#include <string.h>
32
33#include <mbr.h>
34
35#include "endian.h"
36#include "image.h"
37#include "mkimg.h"
38#include "scheme.h"
39
40static struct mkimg_alias ebr_aliases[] = {
41    {	ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16) },
42    {	ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
43    {	ALIAS_FAT32LBA, ALIAS_INT2TYPE(DOSPTYP_FAT32LBA) },
44    {	ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
45    {	ALIAS_NONE, 0 }
46};
47
48static lba_t
49ebr_metadata(u_int where, lba_t blk)
50{
51
52	blk += (where == SCHEME_META_PART_BEFORE) ? 1 : 0;
53	return (round_track(blk));
54}
55
56static void
57ebr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba)
58{
59	u_int cyl, hd, sec;
60
61	mkimg_chs(lba, 1023, &cyl, &hd, &sec);
62	*cylp = cyl;
63	*hdp = hd;
64	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
65}
66
67static int
68ebr_write(lba_t imgsz __unused, void *bootcode __unused)
69{
70	u_char *ebr;
71	struct dos_partition *dp;
72	struct part *part, *next;
73	lba_t block, size;
74	int error;
75
76	ebr = malloc(secsz);
77	if (ebr == NULL)
78		return (ENOMEM);
79	memset(ebr, 0, secsz);
80	le16enc(ebr + DOSMAGICOFFSET, DOSMAGIC);
81
82	error = 0;
83	TAILQ_FOREACH(part, &partlist, link) {
84		block = part->block - nsecs;
85		size = round_track(part->size);
86		dp = (void *)(ebr + DOSPARTOFF);
87		ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect, nsecs);
88		dp->dp_typ = ALIAS_TYPE2INT(part->type);
89		ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
90		    part->block + size - 1);
91		le32enc(&dp->dp_start, nsecs);
92		le32enc(&dp->dp_size, size);
93
94		/* Add link entry */
95		next = TAILQ_NEXT(part, link);
96		if (next != NULL) {
97			size = round_track(next->size);
98			dp++;
99			ebr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
100			    next->block - nsecs);
101			dp->dp_typ = DOSPTYP_EXT;
102			ebr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
103			    next->block + size - 1);
104			le32enc(&dp->dp_start, next->block - nsecs);
105			le32enc(&dp->dp_size, size + nsecs);
106		}
107
108		error = image_write(block, ebr, 1);
109		if (error)
110			break;
111
112		memset(ebr + DOSPARTOFF, 0, 2 * DOSPARTSIZE);
113	}
114
115	free(ebr);
116	return (error);
117}
118
119static struct mkimg_scheme ebr_scheme = {
120	.name = "ebr",
121	.description = "Extended Boot Record",
122	.aliases = ebr_aliases,
123	.metadata = ebr_metadata,
124	.write = ebr_write,
125	.nparts = 4096,
126	.maxsecsz = 4096
127};
128
129SCHEME_DEFINE(ebr_scheme);
130