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 mbr_aliases[] = {
41    {	ALIAS_EBR, ALIAS_INT2TYPE(DOSPTYP_EXT) },
42    {	ALIAS_EFI, ALIAS_INT2TYPE(DOSPTYP_EFI) },
43    {	ALIAS_FAT16B, ALIAS_INT2TYPE(DOSPTYP_FAT16) },
44    {	ALIAS_FAT32, ALIAS_INT2TYPE(DOSPTYP_FAT32) },
45    {	ALIAS_FAT32LBA, ALIAS_INT2TYPE(DOSPTYP_FAT32LBA) },
46    {	ALIAS_FREEBSD, ALIAS_INT2TYPE(DOSPTYP_386BSD) },
47    {	ALIAS_NTFS, ALIAS_INT2TYPE(DOSPTYP_NTFS) },
48    {	ALIAS_PPCBOOT, ALIAS_INT2TYPE(DOSPTYP_PPCBOOT) },
49    {	ALIAS_NONE, 0 }		/* Keep last! */
50};
51
52static lba_t
53mbr_metadata(u_int where, lba_t blk)
54{
55
56	blk += (where == SCHEME_META_IMG_START) ? 1 : 0;
57	return (round_track(blk));
58}
59
60static void
61mbr_chs(u_char *cylp, u_char *hdp, u_char *secp, lba_t lba)
62{
63	u_int cyl, hd, sec;
64
65	mkimg_chs(lba, 1023, &cyl, &hd, &sec);
66	*cylp = cyl;
67	*hdp = hd;
68	*secp = (sec & 0x3f) | ((cyl >> 2) & 0xc0);
69}
70
71static int
72mbr_write(lba_t imgsz __unused, void *bootcode)
73{
74	u_char *mbr;
75	struct dos_partition *dpbase, *dp;
76	struct part *part;
77	lba_t size;
78	int error;
79
80	mbr = malloc(secsz);
81	if (mbr == NULL)
82		return (ENOMEM);
83	if (bootcode != NULL) {
84		memcpy(mbr, bootcode, DOSPARTOFF);
85		memset(mbr + DOSPARTOFF, 0, secsz - DOSPARTOFF);
86	} else
87		memset(mbr, 0, secsz);
88	le16enc(mbr + DOSMAGICOFFSET, DOSMAGIC);
89	dpbase = (void *)(mbr + DOSPARTOFF);
90	TAILQ_FOREACH(part, &partlist, link) {
91		size = round_track(part->size);
92		dp = dpbase + part->index;
93		if (active_partition != 0)
94			dp->dp_flag =
95			    (part->index + 1 == active_partition) ? 0x80 : 0;
96		else
97			dp->dp_flag =
98			    (part->index == 0 && bootcode != NULL) ? 0x80 : 0;
99		mbr_chs(&dp->dp_scyl, &dp->dp_shd, &dp->dp_ssect,
100		    part->block);
101		dp->dp_typ = ALIAS_TYPE2INT(part->type);
102		mbr_chs(&dp->dp_ecyl, &dp->dp_ehd, &dp->dp_esect,
103		    part->block + size - 1);
104		le32enc(&dp->dp_start, part->block);
105		le32enc(&dp->dp_size, size);
106	}
107	error = image_write(0, mbr, 1);
108	free(mbr);
109	return (error);
110}
111
112static struct mkimg_scheme mbr_scheme = {
113	.name = "mbr",
114	.description = "Master Boot Record",
115	.aliases = mbr_aliases,
116	.metadata = mbr_metadata,
117	.write = mbr_write,
118	.bootcode = 512,
119	.nparts = NDOSPART,
120	.maxsecsz = 4096
121};
122
123SCHEME_DEFINE(mbr_scheme);
124