2 * Copyright (c) 2015 Grzegorz Kostka (kostka.grzegorz@gmail.com)
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 /** @addtogroup lwext4
34 * @brief Master boot record parser
37 #include "ext4_config.h"
38 #include "ext4_types.h"
39 #include "ext4_debug.h"
45 #define MBR_SIGNATURE 0xAA55
47 struct ext4_part_entry {
54 } __attribute__((packed));
57 uint8_t bootstrap[446];
58 struct ext4_part_entry part_entry[4];
60 } __attribute__((packed));
63 int ext4_mbr_scan(struct ext4_blockdev *parent, struct ext4_mbr_bdevs *bdevs)
68 ext4_dbg(DEBUG_MBR, DBG_INFO "ext4_mbr_scan\n");
69 memset(bdevs, 0, sizeof(struct ext4_mbr_bdevs));
70 r = ext4_block_init(parent);
74 r = ext4_block_readbytes(parent, 0, parent->bdif->ph_bbuf, 512);
79 const struct ext4_mbr *mbr = (void *)parent->bdif->ph_bbuf;
81 if (to_le16(mbr->signature) != MBR_SIGNATURE) {
82 ext4_dbg(DEBUG_MBR, DBG_ERROR "ext4_mbr_scan: unknown "
83 "signature: 0x%x\n", to_le16(mbr->signature));
88 /*Show bootstrap code*/
89 ext4_dbg(DEBUG_MBR, "mbr_part: bootstrap:");
90 for (i = 0; i < sizeof(mbr->bootstrap); ++i) {
92 ext4_dbg(DEBUG_MBR | DEBUG_NOPREFIX, "\n");
93 ext4_dbg(DEBUG_MBR | DEBUG_NOPREFIX, "%02x, ", mbr->bootstrap[i]);
96 ext4_dbg(DEBUG_MBR | DEBUG_NOPREFIX, "\n\n");
97 for (i = 0; i < 4; ++i) {
98 const struct ext4_part_entry *pe = &mbr->part_entry[i];
99 ext4_dbg(DEBUG_MBR, "mbr_part: %d\n", (int)i);
100 ext4_dbg(DEBUG_MBR, "\tstatus: 0x%x\n", pe->status);
101 ext4_dbg(DEBUG_MBR, "\ttype 0x%x:\n", pe->type);
102 ext4_dbg(DEBUG_MBR, "\tfirst_lba: 0x%"PRIx32"\n", pe->first_lba);
103 ext4_dbg(DEBUG_MBR, "\tsectors: 0x%"PRIx32"\n", pe->sectors);
106 continue; /*Empty entry*/
108 if (pe->type != 0x83)
109 continue; /*Unsupported entry. 0x83 - linux native*/
111 bdevs->partitions[i].bdif = parent->bdif;
112 bdevs->partitions[i].part_offset =
113 (uint64_t)pe->first_lba * parent->bdif->ph_bsize;
114 bdevs->partitions[i].part_size =
115 (uint64_t)pe->sectors * parent->bdif->ph_bsize;
119 ext4_block_fini(parent);