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
40 static 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
52 static lba_t
mbr_metadata(u_int where,lba_t blk)53 mbr_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
60 static void
mbr_chs(u_char * cylp,u_char * hdp,u_char * secp,lba_t lba)61 mbr_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
71 static int
mbr_write(lba_t imgsz __unused,void * bootcode)72 mbr_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
112 static 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
123 SCHEME_DEFINE(mbr_scheme);
124