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
42 static 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
49 static lba_t
ebr_metadata(u_int where,lba_t blk)50 ebr_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
57 static void
ebr_chs(u_char * cylp,u_char * hdp,u_char * secp,lba_t lba)58 ebr_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
68 static int
ebr_write(lba_t imgsz __unused,void * bootcode __unused)69 ebr_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
120 static 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
130 SCHEME_DEFINE(ebr_scheme);
131