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
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/*
* R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
*
* 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
* 2003-03-10 - kharris@nexus-tech.net - ported to u-boot
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _FAT_H_
#define _FAT_H_
#include <asm/byteorder.h>
#include <fs.h>
/* Maximum Long File Name length supported here is 128 UTF-16 code units */
#define VFAT_MAXLEN_BYTES 256 /* Maximum LFN buffer in bytes */
#define VFAT_MAXSEQ 9 /* Up to 9 of 13 2-byte UTF-16 entries */
#define PREFETCH_BLOCKS 2
#define MAX_CLUSTSIZE CONFIG_FS_FAT_MAX_CLUSTSIZE
#define DIRENTSPERBLOCK (mydata->sect_size / sizeof(dir_entry))
#define DIRENTSPERCLUST ((mydata->clust_size * mydata->sect_size) / \
sizeof(dir_entry))
#define FATBUFBLOCKS 6
#define FATBUFSIZE (mydata->sect_size * FATBUFBLOCKS)
#define FAT12BUFSIZE ((FATBUFSIZE*2)/3)
#define FAT16BUFSIZE (FATBUFSIZE/2)
#define FAT32BUFSIZE (FATBUFSIZE/4)
/* Maximum number of entry for long file name according to spec */
#define MAX_LFN_SLOT 20
/* Filesystem identifiers */
#define FAT12_SIGN "FAT12 "
#define FAT16_SIGN "FAT16 "
#define FAT32_SIGN "FAT32 "
#define SIGNLEN 8
/* File attributes */
#define ATTR_RO 1
#define ATTR_HIDDEN 2
#define ATTR_SYS 4
#define ATTR_VOLUME 8
#define ATTR_DIR 16
#define ATTR_ARCH 32
#define ATTR_VFAT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
#define DELETED_FLAG ((char)0xe5) /* Marks deleted files when in name[0] */
#define aRING 0x05 /* Used as special character in name[0] */
/*
* Indicates that the entry is the last long entry in a set of long
* dir entries
*/
#define LAST_LONG_ENTRY_MASK 0x40
#define ISDIRDELIM(c) ((c) == '/' || (c) == '\\')
#define FSTYPE_NONE (-1)
#if defined(__linux__) && defined(__KERNEL__)
#define FAT2CPU16 le16_to_cpu
#define FAT2CPU32 le32_to_cpu
#else
#if __LITTLE_ENDIAN
#define FAT2CPU16(x) (x)
#define FAT2CPU32(x) (x)
#else
#define FAT2CPU16(x) ((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
#define FAT2CPU32(x) ((((x) & 0x000000ff) << 24) | \
(((x) & 0x0000ff00) << 8) | \
(((x) & 0x00ff0000) >> 8) | \
(((x) & 0xff000000) >> 24))
#endif
#endif
#define START(dent) (FAT2CPU16((dent)->start) \
+ (mydata->fatsize != 32 ? 0 : \
(FAT2CPU16((dent)->starthi) << 16)))
#define IS_LAST_CLUST(x, fatsize) ((x) >= ((fatsize) != 32 ? \
((fatsize) != 16 ? 0xff8 : 0xfff8) : \
0xffffff8))
#define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
(x) >= ((fatsize) != 32 ? \
((fatsize) != 16 ? 0xff0 : 0xfff0) : \
0xffffff0))
typedef struct boot_sector {
__u8 ignored[3]; /* Bootstrap code */
char system_id[8]; /* Name of fs */
__u8 sector_size[2]; /* Bytes/sector */
__u8 cluster_size; /* Sectors/cluster */
__u16 reserved; /* Number of reserved sectors */
__u8 fats; /* Number of FATs */
__u8 dir_entries[2]; /* Number of root directory entries */
__u8 sectors[2]; /* Number of sectors */
__u8 media; /* Media code */
__u16 fat_length; /* Sectors/FAT */
__u16 secs_track; /* Sectors/track */
__u16 heads; /* Number of heads */
__u32 hidden; /* Number of hidden sectors */
__u32 total_sect; /* Number of sectors (if sectors == 0) */
/* FAT32 only */
__u32 fat32_length; /* Sectors/FAT */
__u16 flags; /* Bit 8: fat mirroring, low 4: active fat */
__u8 version[2]; /* Filesystem version */
__u32 root_cluster; /* First cluster in root directory */
__u16 info_sector; /* Filesystem info sector */
__u16 backup_boot; /* Backup boot sector */
__u16 reserved2[6]; /* Unused */
} boot_sector;
typedef struct volume_info
{
__u8 drive_number; /* BIOS drive number */
__u8 reserved; /* Unused */
__u8 ext_boot_sign; /* 0x29 if fields below exist (DOS 3.3+) */
__u8 volume_id[4]; /* Volume ID number */
char volume_label[11]; /* Volume label */
char fs_type[8]; /* Typically FAT12, FAT16, or FAT32 */
/* Boot code comes next, all but 2 bytes to fill up sector */
/* Boot sign comes last, 2 bytes */
} volume_info;
/* see dir_entry::lcase: */
#define CASE_LOWER_BASE 8 /* base (name) is lower case */
#define CASE_LOWER_EXT 16 /* extension is lower case */
typedef struct dir_entry {
char name[8],ext[3]; /* Name and extension */
__u8 attr; /* Attribute bits */
__u8 lcase; /* Case for name and ext (CASE_LOWER_x) */
__u8 ctime_ms; /* Creation time, milliseconds */
__u16 ctime; /* Creation time */
__u16 cdate; /* Creation date */
__u16 adate; /* Last access date */
__u16 starthi; /* High 16 bits of cluster in FAT32 */
__u16 time,date,start;/* Time, date and first cluster */
__u32 size; /* File size in bytes */
} dir_entry;
typedef struct dir_slot {
__u8 id; /* Sequence number for slot */
__u8 name0_4[10]; /* First 5 characters in name */
__u8 attr; /* Attribute byte */
__u8 reserved; /* Unused */
__u8 alias_checksum;/* Checksum for 8.3 alias */
__u8 name5_10[12]; /* 6 more characters in name */
__u16 start; /* Unused */
__u8 name11_12[4]; /* Last 2 characters in name */
} dir_slot;
/*
* Private filesystem parameters
*
* Note: FAT buffer has to be 32 bit aligned
* (see FAT32 accesses)
*/
typedef struct {
__u8 *fatbuf; /* Current FAT buffer */
int fatsize; /* Size of FAT in bits */
__u32 fatlength; /* Length of FAT in sectors */
__u16 fat_sect; /* Starting sector of the FAT */
__u8 fat_dirty; /* Set if fatbuf has been modified */
__u32 rootdir_sect; /* Start sector of root directory */
__u16 sect_size; /* Size of sectors in bytes */
__u16 clust_size; /* Size of clusters in sectors */
int data_begin; /* The sector of the first cluster, can be negative */
int fatbufnum; /* Used by get_fatent, init to -1 */
int rootdir_size; /* Size of root dir for non-FAT32 */
__u32 root_cluster; /* First cluster of root dir for FAT32 */
} fsdata;
static inline u32 clust_to_sect(fsdata *fsdata, u32 clust)
{
return fsdata->data_begin + clust * fsdata->clust_size;
}
static inline u32 sect_to_clust(fsdata *fsdata, u32 sect)
{
return (sect - fsdata->data_begin) / fsdata->clust_size;
}
int file_fat_detectfs(void);
int fat_exists(const char *filename);
int fat_size(const char *filename, loff_t *size);
int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
loff_t maxsize, loff_t *actread);
int file_fat_read(const char *filename, void *buffer, int maxsize);
int fat_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info);
int fat_register_device(struct blk_desc *dev_desc, int part_no);
int file_fat_write(const char *filename, void *buf, loff_t offset, loff_t len,
loff_t *actwrite);
int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
loff_t *actread);
int fat_opendir(const char *filename, struct fs_dir_stream **dirsp);
int fat_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp);
void fat_closedir(struct fs_dir_stream *dirs);
void fat_close(void);
#endif /* _FAT_H_ */
|
