3 * esd gmbh <www.esd-electronics.com>
4 * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
6 * based on code of fs/reiserfs/dev.c by
8 * (C) Copyright 2003 - 2004
9 * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
31 static block_dev_desc_t *ext2fs_block_dev_desc;
32 static disk_partition_t part_info;
34 int ext2fs_set_blk_dev(block_dev_desc_t *rbdd, int part)
36 ext2fs_block_dev_desc = rbdd;
39 /* disk doesn't use partition table */
41 part_info.size = rbdd->lba;
42 part_info.blksz = rbdd->blksz;
44 if (get_partition_info
45 (ext2fs_block_dev_desc, part, &part_info)) {
49 return part_info.size;
53 int ext2fs_devread(int sector, int byte_offset, int byte_len, char *buf)
55 char sec_buf[SECTOR_SIZE];
59 * Check partition boundaries
62 ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >=
64 /* errnum = ERR_OUTSIDE_PART; */
65 printf(" ** %s read outside partition sector %d\n",
72 * Get the read to the beginning of a partition.
74 sector += byte_offset >> SECTOR_BITS;
75 byte_offset &= SECTOR_SIZE - 1;
77 debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
79 if (ext2fs_block_dev_desc == NULL) {
80 printf(" ** %s Invalid Block Device Descriptor (NULL)\n",
85 if (byte_offset != 0) {
86 /* read first part which isn't aligned with start of sector */
87 if (ext2fs_block_dev_desc->
88 block_read(ext2fs_block_dev_desc->dev,
89 part_info.start + sector, 1,
90 (unsigned long *) sec_buf) != 1) {
91 printf(" ** %s read error **\n", __func__);
94 memcpy(buf, sec_buf + byte_offset,
95 min(SECTOR_SIZE - byte_offset, byte_len));
96 buf += min(SECTOR_SIZE - byte_offset, byte_len);
97 byte_len -= min(SECTOR_SIZE - byte_offset, byte_len);
101 /* read sector aligned part */
102 sectors = byte_len / SECTOR_SIZE;
105 if (ext2fs_block_dev_desc->block_read(
106 ext2fs_block_dev_desc->dev,
107 part_info.start + sector,
109 (unsigned long *) buf) != sectors) {
110 printf(" ** %s read error - block\n", __func__);
114 buf += sectors * SECTOR_SIZE;
115 byte_len -= sectors * SECTOR_SIZE;
120 /* read rest of data which are not in whole sector */
121 if (ext2fs_block_dev_desc->
122 block_read(ext2fs_block_dev_desc->dev,
123 part_info.start + sector, 1,
124 (unsigned long *) sec_buf) != 1) {
125 printf(" ** %s read error - last part\n", __func__);
128 memcpy(buf, sec_buf, byte_len);