blob: 58b441030c863dda0ce0ea202b949735e088d024 [file] [log] [blame]
Marek BehĂșn5994e8b2017-09-03 17:00:24 +02001/*
2 * 2017 by Marek Behun <marek.behun@nic.cz>
3 *
4 * Derived from code in ext4/dev.c, which was based on reiserfs/dev.c
5 *
6 * SPDX-License-Identifier: GPL-2.0
7 */
8
9#include <common.h>
10#include <compiler.h>
11#include <part.h>
12#include <memalign.h>
13
14int fs_devread(struct blk_desc *blk, disk_partition_t *partition,
15 lbaint_t sector, int byte_offset, int byte_len, char *buf)
16{
17 unsigned block_len;
18 int log2blksz = blk->log2blksz;
19 ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (blk ? blk->blksz : 0));
20 if (blk == NULL) {
21 printf("** Invalid Block Device Descriptor (NULL)\n");
22 return 0;
23 }
24
25 /* Check partition boundaries */
26 if ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
27 >= partition->size) {
28 printf("%s read outside partition " LBAFU "\n", __func__,
29 sector);
30 return 0;
31 }
32
33 /* Get the read to the beginning of a partition */
34 sector += byte_offset >> log2blksz;
35 byte_offset &= blk->blksz - 1;
36
37 debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
38
39 if (byte_offset != 0) {
40 int readlen;
41 /* read first part which isn't aligned with start of sector */
42 if (blk_dread(blk, partition->start + sector, 1,
43 (void *)sec_buf) != 1) {
44 printf(" ** %s read error **\n", __func__);
45 return 0;
46 }
47 readlen = min((int)blk->blksz - byte_offset,
48 byte_len);
49 memcpy(buf, sec_buf + byte_offset, readlen);
50 buf += readlen;
51 byte_len -= readlen;
52 sector++;
53 }
54
55 if (byte_len == 0)
56 return 1;
57
58 /* read sector aligned part */
59 block_len = byte_len & ~(blk->blksz - 1);
60
61 if (block_len == 0) {
62 ALLOC_CACHE_ALIGN_BUFFER(u8, p, blk->blksz);
63
64 block_len = blk->blksz;
65 blk_dread(blk, partition->start + sector, 1,
66 (void *)p);
67 memcpy(buf, p, byte_len);
68 return 1;
69 }
70
71 if (blk_dread(blk, partition->start + sector,
72 block_len >> log2blksz, (void *)buf) !=
73 block_len >> log2blksz) {
74 printf(" ** %s read error - block\n", __func__);
75 return 0;
76 }
77 block_len = byte_len & ~(blk->blksz - 1);
78 buf += block_len;
79 byte_len -= block_len;
80 sector += block_len / blk->blksz;
81
82 if (byte_len != 0) {
83 /* read rest of data which are not in whole sector */
84 if (blk_dread(blk, partition->start + sector, 1,
85 (void *)sec_buf) != 1) {
86 printf("* %s read error - last part\n", __func__);
87 return 0;
88 }
89 memcpy(buf, sec_buf, byte_len);
90 }
91 return 1;
92}