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