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
|
#include "sysincludes.h"
#include "old_dos.h"
static struct OldDos_t old_dos[]={
{ 40, 9, 1, 4, 1, 2, 0xfc }, /* 180 KB */
{ 40, 9, 2, 7, 2, 2, 0xfd }, /* 360 KB */
{ 40, 8, 1, 4, 1, 1, 0xfe }, /* 160 KB */
{ 40, 8, 2, 7, 2, 1, 0xff }, /* 320 KB */
{ 80, 9, 2, 7, 2, 3, 0xf9 }, /* 720 KB */
{ 80, 15, 2,14, 1, 7, 0xf9 }, /* 1200 KB */
{ 80, 18, 2,14, 1, 9, 0xf0 }, /* 1440 KB */
{ 80, 36, 2,15, 2, 9, 0xf0 }, /* 2880 KB */
/* Source: https://en.wikipedia.org/w/index.php?title=File_Allocation_Table&oldid=560606333#Exceptions : */
/* https://www.win.tue.nl/~aeb/linux/fs/fat/fat-1.html */
{ 80, 8, 2, 7, 2, 2, 0xfb }, /* 640 KB */
{ 80, 8, 1, 7, 2, 2, 0xfa }, /* 320 KB */
{ 80, 9, 1, 7, 2, 2, 0xf8 }, /* 360 KB */
};
/**
* Get Old Dos parameters for a filesystem of size KBytes (assuming
* 512 byte sectors), i.e. number of sectors is double the size
*/
struct OldDos_t *getOldDosBySize(size_t size) {
size_t i;
size = size * 2;
for(i=0; i < sizeof(old_dos) / sizeof(old_dos[0]); i++){
if (old_dos[i].sectors *
old_dos[i].tracks *
old_dos[i].heads == size)
return &old_dos[i];
}
return NULL;
}
struct OldDos_t *getOldDosByMedia(int media) {
size_t i;
for(i=0; i < sizeof(old_dos) / sizeof(old_dos[0]); i++){
if (old_dos[i].media == media)
return &old_dos[i];
}
fprintf(stderr, "Unknown media type %02x\n", media);
return NULL;
}
struct OldDos_t *getOldDosByParams(unsigned int tracks,
unsigned int heads,
unsigned int sectors,
unsigned int dir_len,
unsigned int cluster_size) {
size_t i;
for(i=0; i < sizeof(old_dos) / sizeof(old_dos[0]); i++){
if (sectors == old_dos[i].sectors &&
tracks == old_dos[i].tracks &&
heads == old_dos[i].heads &&
(dir_len == 0 || dir_len == old_dos[i].dir_len) &&
(cluster_size == 0 ||
cluster_size == old_dos[i].cluster_size)) {
return &old_dos[i];
}
}
return NULL;
}
int setDeviceFromOldDos(int media, struct device *dev) {
struct OldDos_t *params=getOldDosByMedia(media);
if(params == NULL)
return -1;
dev->heads = params->heads;
dev->tracks = params->tracks;
dev->sectors = params->sectors;
dev->ssize = 0x80;
dev->use_2m = ~1u;
return 0;
}
|
