2 * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
4 * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
5 * 2003-03-10 - kharris@nexus-tech.net - ported to u-boot
7 * SPDX-License-Identifier: GPL-2.0+
13 #include <asm/byteorder.h>
15 #define CONFIG_SUPPORT_VFAT
16 /* Maximum Long File Name length supported here is 128 UTF-16 code units */
17 #define VFAT_MAXLEN_BYTES 256 /* Maximum LFN buffer in bytes */
18 #define VFAT_MAXSEQ 9 /* Up to 9 of 13 2-byte UTF-16 entries */
19 #define PREFETCH_BLOCKS 2
21 #define MAX_CLUSTSIZE CONFIG_FS_FAT_MAX_CLUSTSIZE
23 #define DIRENTSPERBLOCK (mydata->sect_size / sizeof(dir_entry))
24 #define DIRENTSPERCLUST ((mydata->clust_size * mydata->sect_size) / \
27 #define FATBUFBLOCKS 6
28 #define FATBUFSIZE (mydata->sect_size * FATBUFBLOCKS)
29 #define FAT12BUFSIZE ((FATBUFSIZE*2)/3)
30 #define FAT16BUFSIZE (FATBUFSIZE/2)
31 #define FAT32BUFSIZE (FATBUFSIZE/4)
33 /* Maximum number of entry for long file name according to spec */
34 #define MAX_LFN_SLOT 20
36 /* Filesystem identifiers */
37 #define FAT12_SIGN "FAT12 "
38 #define FAT16_SIGN "FAT16 "
39 #define FAT32_SIGN "FAT32 "
50 #define ATTR_VFAT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
52 #define DELETED_FLAG ((char)0xe5) /* Marks deleted files when in name[0] */
53 #define aRING 0x05 /* Used as special character in name[0] */
56 * Indicates that the entry is the last long entry in a set of long
59 #define LAST_LONG_ENTRY_MASK 0x40
61 /* Flags telling whether we should read a file or list a directory */
67 #define ISDIRDELIM(c) ((c) == '/' || (c) == '\\')
69 #define FSTYPE_NONE (-1)
71 #if defined(__linux__) && defined(__KERNEL__)
72 #define FAT2CPU16 le16_to_cpu
73 #define FAT2CPU32 le32_to_cpu
76 #define FAT2CPU16(x) (x)
77 #define FAT2CPU32(x) (x)
79 #define FAT2CPU16(x) ((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
80 #define FAT2CPU32(x) ((((x) & 0x000000ff) << 24) | \
81 (((x) & 0x0000ff00) << 8) | \
82 (((x) & 0x00ff0000) >> 8) | \
83 (((x) & 0xff000000) >> 24))
87 #define START(dent) (FAT2CPU16((dent)->start) \
88 + (mydata->fatsize != 32 ? 0 : \
89 (FAT2CPU16((dent)->starthi) << 16)))
90 #define IS_LAST_CLUST(x, fatsize) ((x) >= ((fatsize) != 32 ? \
91 ((fatsize) != 16 ? 0xff8 : 0xfff8) : \
93 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
94 (x) >= ((fatsize) != 32 ? \
95 ((fatsize) != 16 ? 0xff0 : 0xfff0) : \
98 typedef struct boot_sector
{
99 __u8 ignored
[3]; /* Bootstrap code */
100 char system_id
[8]; /* Name of fs */
101 __u8 sector_size
[2]; /* Bytes/sector */
102 __u8 cluster_size
; /* Sectors/cluster */
103 __u16 reserved
; /* Number of reserved sectors */
104 __u8 fats
; /* Number of FATs */
105 __u8 dir_entries
[2]; /* Number of root directory entries */
106 __u8 sectors
[2]; /* Number of sectors */
107 __u8 media
; /* Media code */
108 __u16 fat_length
; /* Sectors/FAT */
109 __u16 secs_track
; /* Sectors/track */
110 __u16 heads
; /* Number of heads */
111 __u32 hidden
; /* Number of hidden sectors */
112 __u32 total_sect
; /* Number of sectors (if sectors == 0) */
115 __u32 fat32_length
; /* Sectors/FAT */
116 __u16 flags
; /* Bit 8: fat mirroring, low 4: active fat */
117 __u8 version
[2]; /* Filesystem version */
118 __u32 root_cluster
; /* First cluster in root directory */
119 __u16 info_sector
; /* Filesystem info sector */
120 __u16 backup_boot
; /* Backup boot sector */
121 __u16 reserved2
[6]; /* Unused */
124 typedef struct volume_info
126 __u8 drive_number
; /* BIOS drive number */
127 __u8 reserved
; /* Unused */
128 __u8 ext_boot_sign
; /* 0x29 if fields below exist (DOS 3.3+) */
129 __u8 volume_id
[4]; /* Volume ID number */
130 char volume_label
[11]; /* Volume label */
131 char fs_type
[8]; /* Typically FAT12, FAT16, or FAT32 */
132 /* Boot code comes next, all but 2 bytes to fill up sector */
133 /* Boot sign comes last, 2 bytes */
136 typedef struct dir_entry
{
137 char name
[8],ext
[3]; /* Name and extension */
138 __u8 attr
; /* Attribute bits */
139 __u8 lcase
; /* Case for base and extension */
140 __u8 ctime_ms
; /* Creation time, milliseconds */
141 __u16 ctime
; /* Creation time */
142 __u16 cdate
; /* Creation date */
143 __u16 adate
; /* Last access date */
144 __u16 starthi
; /* High 16 bits of cluster in FAT32 */
145 __u16 time
,date
,start
;/* Time, date and first cluster */
146 __u32 size
; /* File size in bytes */
149 typedef struct dir_slot
{
150 __u8 id
; /* Sequence number for slot */
151 __u8 name0_4
[10]; /* First 5 characters in name */
152 __u8 attr
; /* Attribute byte */
153 __u8 reserved
; /* Unused */
154 __u8 alias_checksum
;/* Checksum for 8.3 alias */
155 __u8 name5_10
[12]; /* 6 more characters in name */
156 __u16 start
; /* Unused */
157 __u8 name11_12
[4]; /* Last 2 characters in name */
161 * Private filesystem parameters
163 * Note: FAT buffer has to be 32 bit aligned
164 * (see FAT32 accesses)
167 __u8
*fatbuf
; /* Current FAT buffer */
168 int fatsize
; /* Size of FAT in bits */
169 __u32 fatlength
; /* Length of FAT in sectors */
170 __u16 fat_sect
; /* Starting sector of the FAT */
171 __u8 fat_dirty
; /* Set if fatbuf has been modified */
172 __u32 rootdir_sect
; /* Start sector of root directory */
173 __u16 sect_size
; /* Size of sectors in bytes */
174 __u16 clust_size
; /* Size of clusters in sectors */
175 int data_begin
; /* The sector of the first cluster, can be negative */
176 int fatbufnum
; /* Used by get_fatent, init to -1 */
177 int rootdir_size
; /* Size of root dir for non-FAT32 */
178 __u32 root_cluster
; /* First cluster of root dir for FAT32 */
181 /* TODO clean up places that are open-coding this: */
182 static inline u32
clust_to_sect(fsdata
*fsdata
, u32 clust
)
184 return fsdata
->data_begin
+ clust
* fsdata
->clust_size
;
187 typedef int (file_detectfs_func
)(void);
188 typedef int (file_ls_func
)(const char *dir
);
189 typedef int (file_read_func
)(const char *filename
, void *buffer
,
193 file_detectfs_func
*detect
;
195 file_read_func
*read
;
200 file_detectfs_func file_fat_detectfs
;
201 file_ls_func file_fat_ls
;
202 file_read_func file_fat_read
;
204 /* Currently this doesn't check if the dir exists or is valid... */
205 int file_cd(const char *path
);
206 int file_fat_detectfs(void);
207 int file_fat_ls(const char *dir
);
208 int fat_exists(const char *filename
);
209 int fat_size(const char *filename
, loff_t
*size
);
210 int file_fat_read_at(const char *filename
, loff_t pos
, void *buffer
,
211 loff_t maxsize
, loff_t
*actread
);
212 int file_fat_read(const char *filename
, void *buffer
, int maxsize
);
213 const char *file_getfsname(int idx
);
214 int fat_set_blk_dev(struct blk_desc
*rbdd
, disk_partition_t
*info
);
215 int fat_register_device(struct blk_desc
*dev_desc
, int part_no
);
217 int file_fat_write(const char *filename
, void *buf
, loff_t offset
, loff_t len
,
219 int fat_read_file(const char *filename
, void *buf
, loff_t offset
, loff_t len
,
221 void fat_close(void);