1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
|
#include <stdint.h>
#include <kernel/lib/stdlib.h>
#include <kernel/fs/ata_pio.h>
#include <kernel/fs/marfs/marfs.h>
uint8_t marfs_init(struct ata_interface *_interface)
{
interface = _interface;
uint16_t identify_data[256 * 2];
uint8_t ret = ata_identify(interface, identify_data);
max_lba = (identify_data[61] << 16) + identify_data[60];
return ret;
}
uint32_t marfs_get_max_lba(void)
{
return max_lba;
}
uint8_t marfs_write_mbr(uint8_t *mbr)
{
return ata_write28(interface, 0, mbr);
}
struct marfs_superblock *marfs_read_superblock()
{
struct marfs_superblock *p = (struct marfs_superblock *) ata_read28(interface, 1);
sb_cache = *p;
return p;
}
uint8_t marfs_write_superblock(struct marfs_superblock *sb)
{
sb_cache = *sb;
return ata_write28(interface, 1, (uint8_t *) sb);
}
uint32_t marfs_get_free_lba_block(void)
{
uint32_t offset = 2 + sb_cache.s_first_chunk;
uint8_t *p = 0;
for (uint32_t i = 0; i < sb_cache.n_chunks; i++) {
p = ata_read28(interface, offset);
if (!(*p & 0x80)) break;
kfree(p);
offset += 512;
}
offset++;
for (uint16_t i = 1; i < 512; i++) {
if (!p[i]) break;
offset++;
}
kfree(p);
ata_clear28(interface, offset);
return offset;
}
static uint8_t marfs_mark_block(uint32_t lba_sector, uint8_t mode)
{
lba_sector -= 2;
lba_sector -= sb_cache.s_first_chunk;
uint16_t block_in_chunk = lba_sector % 512;
lba_sector /= 512;
lba_sector = 2 + sb_cache.s_first_chunk + (512 * lba_sector);
uint8_t *p = ata_read28(interface, lba_sector);
p[block_in_chunk] = mode;
if (mode == 0) {
p[0] = 0;
} else {
uint8_t full_chunk = 1;
for (uint16_t i = 1; i < 512; i++) {
if (!p[i]) {
full_chunk = 0;
break;
}
}
p[0] = full_chunk;
}
uint8_t ret = ata_write28(interface, lba_sector, p);
kfree(p);
return ret;
}
uint8_t marfs_mark_block_as_free(uint32_t lba_sector)
{
return marfs_mark_block(lba_sector, 0);
}
uint8_t marfs_mark_block_as_used(uint32_t lba_sector)
{
return marfs_mark_block(lba_sector, 1);
}
uint32_t marfs_get_free_lba_inode(void)
{
uint32_t offset;
for (offset = 2; offset < 2 + sb_cache.n_inodes; offset++) {
struct marfs_inode *inode = (struct marfs_inode *) ata_read28(interface, offset);
uint8_t used = inode->is_used;
kfree(inode);
if (!used) break;
}
return offset;
}
void marfs_mark_inode_as_free(uint32_t lba_sector)
{
struct marfs_inode *inode = (struct marfs_inode *) ata_read28(interface, lba_sector);
inode->is_used = 0;
ata_write28(interface, lba_sector, (uint8_t *) inode);
kfree(inode);
}
|
