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#ifndef DOSPTYP_EFI
49#define	DOSPTYP_EFI	0xef
50#endif
51
52static struct mkimg_alias mbr_aliases[] = {
53    {	ALIAS_EBR, ALIAS_INT2TYPE(DOSPTYP_EXT) },
54    {	ALIAS_EFI, ALIAS_INT2TYPE(DOSPTYP_EFI) },
55    {	ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16B) },
56    {	ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
57    {	ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
58    {	ALIAS_NTFS, ALIAS_INT2TYPE(DOSPTYP_NTFS) },
59    {	ALIAS_NONE, 0 }		/* Keep last! */
60};
61
62static lba_t
63mbr_metadata(u_int where, lba_t blk)
64{
65
66	blk += (where == SCHEME_META_IMG_START) ? 1 : 0;
67	return (round_track(blk));
68}
69
70static void
71mbr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba)
72{
73	u_int cyl, hd, sec;
74
75	mkimg_chs(lba, 1023, &cyl, &hd, &sec);
76	*cylp = cyl;
77	*hdp = hd;
78	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
79}
80
81static int
82mbr_write(lba_t imgsz __unused, void *bootcode)
83{
84	u_char *mbr;
85	struct dos_partition *dpbase, *dp;
86	struct part *part;
87	lba_t size;
88	int error;
89
90	mbr = malloc(secsz);
91	if (mbr == NULL)
92		return (ENOMEM);
93	if (bootcode != NULL) {
94		memcpy(mbr, bootcode, DOSPARTOFF);
95		memset(mbr + DOSPARTOFF, 0, secsz - DOSPARTOFF);
96	} else
97		memset(mbr, 0, secsz);
98	le16enc(mbr + DOSMAGICOFFSET, DOSMAGIC);
99	dpbase = (void *)(mbr + DOSPARTOFF);
100	STAILQ_FOREACH(part, &partlist, link) {
101		size = round_track(part->size);
102		dp = dpbase + part->index;
103		dp->dp_flag = (part->index == 0 && bootcode != NULL) ? 0x80 : 0;
104		mbr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
105		    part->block);
106		dp->dp_typ = ALIAS_TYPE2INT(part->type);
107		mbr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
108		    part->block + size - 1);
109		le32enc(&dp->dp_start, part->block);
110		le32enc(&dp->dp_size, size);
111	}
112	error = image_write(0, mbr, 1);
113	free(mbr);
114	return (error);
115}
116
117static struct mkimg_scheme mbr_scheme = {
118	.name = "mbr",
119	.description = "Master Boot Record",
120	.aliases = mbr_aliases,
121	.metadata = mbr_metadata,
122	.write = mbr_write,
123	.bootcode = 512,
124	.nparts = NDOSPART,
125	.maxsecsz = 4096
126};
127
128SCHEME_DEFINE(mbr_scheme);
129