1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * R/O (V)FAT 12/16/32 filesystem implementation by Marcus Sundberg
4 *
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
7 */
8
9 #ifndef _FAT_H_
10 #define _FAT_H_
11
12 #include <fs.h>
13 #include <asm/byteorder.h>
14 #include <asm/cache.h>
15
16 struct disk_partition;
17
18 /* Maximum Long File Name length supported here is 128 UTF-16 code units */
19 #define VFAT_MAXLEN_BYTES 256 /* Maximum LFN buffer in bytes */
20 #define VFAT_MAXSEQ 9 /* Up to 9 of 13 2-byte UTF-16 entries */
21 #define PREFETCH_BLOCKS 2
22
23 #define MAX_CLUSTSIZE CONFIG_FS_FAT_MAX_CLUSTSIZE
24
25 #define DIRENTSPERCLUST ((mydata->clust_size * mydata->sect_size) / \
26 sizeof(dir_entry))
27
28 #define FATBUFBLOCKS 6
29 #define FATBUFSIZE (mydata->sect_size * FATBUFBLOCKS)
30 #define FAT12BUFSIZE ((FATBUFSIZE*2)/3)
31 #define FAT16BUFSIZE (FATBUFSIZE/2)
32 #define FAT32BUFSIZE (FATBUFSIZE/4)
33
34 /* Maximum number of entry for long file name according to spec */
35 #define MAX_LFN_SLOT 20
36
37 /* Filesystem identifiers */
38 #define FAT12_SIGN "FAT12 "
39 #define FAT16_SIGN "FAT16 "
40 #define FAT32_SIGN "FAT32 "
41 #define SIGNLEN 8
42
43 /* File attributes */
44 #define ATTR_RO 1
45 #define ATTR_HIDDEN 2
46 #define ATTR_SYS 4
47 #define ATTR_VOLUME 8
48 #define ATTR_DIR 16
49 #define ATTR_ARCH 32
50
51 #define ATTR_VFAT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
52
53 #define DELETED_FLAG ((char)0xe5) /* Marks deleted files when in name[0] */
54 #define aRING 0x05 /* Used as special character in name[0] */
55
56 /*
57 * Indicates that the entry is the last long entry in a set of long
58 * dir entries
59 */
60 #define LAST_LONG_ENTRY_MASK 0x40
61
62 #define ISDIRDELIM(c) ((c) == '/' || (c) == '\\')
63
64 #define FSTYPE_NONE (-1)
65
66 #if defined(__linux__) && defined(__KERNEL__)
67 #define FAT2CPU16 le16_to_cpu
68 #define FAT2CPU32 le32_to_cpu
69 #else
70 #if __LITTLE_ENDIAN
71 #define FAT2CPU16(x) (x)
72 #define FAT2CPU32(x) (x)
73 #else
74 #define FAT2CPU16(x) ((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
75 #define FAT2CPU32(x) ((((x) & 0x000000ff) << 24) | \
76 (((x) & 0x0000ff00) << 8) | \
77 (((x) & 0x00ff0000) >> 8) | \
78 (((x) & 0xff000000) >> 24))
79 #endif
80 #endif
81
82 #define START(dent) (FAT2CPU16((dent)->start) \
83 + (mydata->fatsize != 32 ? 0 : \
84 (FAT2CPU16((dent)->starthi) << 16)))
85 #define IS_LAST_CLUST(x, fatsize) ((x) >= ((fatsize) != 32 ? \
86 ((fatsize) != 16 ? 0xff8 : 0xfff8) : \
87 0xffffff8))
88 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
89 (x) >= ((fatsize) != 32 ? \
90 ((fatsize) != 16 ? 0xff0 : 0xfff0) : \
91 0xffffff0))
92
93 typedef struct boot_sector {
94 __u8 ignored[3]; /* Bootstrap code */
95 char system_id[8]; /* Name of fs */
96 __u8 sector_size[2]; /* Bytes/sector */
97 __u8 cluster_size; /* Sectors/cluster */
98 __u16 reserved; /* Number of reserved sectors */
99 __u8 fats; /* Number of FATs */
100 __u8 dir_entries[2]; /* Number of root directory entries */
101 __u8 sectors[2]; /* Number of sectors */
102 __u8 media; /* Media code */
103 __u16 fat_length; /* Sectors/FAT */
104 __u16 secs_track; /* Sectors/track */
105 __u16 heads; /* Number of heads */
106 __u32 hidden; /* Number of hidden sectors */
107 __u32 total_sect; /* Number of sectors (if sectors == 0) */
108
109 /* FAT32 only */
110 __u32 fat32_length; /* Sectors/FAT */
111 __u16 flags; /* Bit 8: fat mirroring, low 4: active fat */
112 __u8 version[2]; /* Filesystem version */
113 __u32 root_cluster; /* First cluster in root directory */
114 __u16 info_sector; /* Filesystem info sector */
115 __u16 backup_boot; /* Backup boot sector */
116 __u16 reserved2[6]; /* Unused */
117 } boot_sector;
118
119 typedef struct volume_info
120 {
121 __u8 drive_number; /* BIOS drive number */
122 __u8 reserved; /* Unused */
123 __u8 ext_boot_sign; /* 0x29 if fields below exist (DOS 3.3+) */
124 __u8 volume_id[4]; /* Volume ID number */
125 char volume_label[11]; /* Volume label */
126 char fs_type[8]; /* Typically FAT12, FAT16, or FAT32 */
127 /* Boot code comes next, all but 2 bytes to fill up sector */
128 /* Boot sign comes last, 2 bytes */
129 } volume_info;
130
131 /* see dir_entry::lcase: */
132 #define CASE_LOWER_BASE 8 /* base (name) is lower case */
133 #define CASE_LOWER_EXT 16 /* extension is lower case */
134
135 struct nameext {
136 char name[8];
137 char ext[3];
138 };
139
140 typedef struct dir_entry {
141 struct nameext nameext; /* Name and extension */
142 __u8 attr; /* Attribute bits */
143 __u8 lcase; /* Case for name and ext (CASE_LOWER_x) */
144 __u8 ctime_ms; /* Creation time, milliseconds */
145 __u16 ctime; /* Creation time */
146 __u16 cdate; /* Creation date */
147 __u16 adate; /* Last access date */
148 __u16 starthi; /* High 16 bits of cluster in FAT32 */
149 __u16 time,date,start;/* Time, date and first cluster */
150 __u32 size; /* File size in bytes */
151 } dir_entry;
152
153 typedef struct dir_slot {
154 __u8 id; /* Sequence number for slot */
155 __u8 name0_4[10]; /* First 5 characters in name */
156 __u8 attr; /* Attribute byte */
157 __u8 reserved; /* Unused */
158 __u8 alias_checksum;/* Checksum for 8.3 alias */
159 __u8 name5_10[12]; /* 6 more characters in name */
160 __u16 start; /* Unused */
161 __u8 name11_12[4]; /* Last 2 characters in name */
162 } dir_slot;
163
164 /*
165 * Private filesystem parameters
166 *
167 * Note: FAT buffer has to be 32 bit aligned
168 * (see FAT32 accesses)
169 */
170 typedef struct {
171 __u8 *fatbuf; /* Current FAT buffer */
172 int fatsize; /* Size of FAT in bits */
173 __u32 fatlength; /* Length of FAT in sectors */
174 __u16 fat_sect; /* Starting sector of the FAT */
175 __u8 fat_dirty; /* Set if fatbuf has been modified */
176 __u32 rootdir_sect; /* Start sector of root directory */
177 __u16 sect_size; /* Size of sectors in bytes */
178 __u16 clust_size; /* Size of clusters in sectors */
179 int data_begin; /* The sector of the first cluster, can be negative */
180 int fatbufnum; /* Used by get_fatent, init to -1 */
181 int rootdir_size; /* Size of root dir for non-FAT32 */
182 __u32 root_cluster; /* First cluster of root dir for FAT32 */
183 u32 total_sect; /* Number of sectors */
184 int fats; /* Number of FATs */
185 } fsdata;
186
187 struct fat_itr;
188 typedef struct fat_itr fat_itr;
189
clust_to_sect(fsdata * fsdata,u32 clust)190 static inline u32 clust_to_sect(fsdata *fsdata, u32 clust)
191 {
192 return fsdata->data_begin + clust * fsdata->clust_size;
193 }
194
sect_to_clust(fsdata * fsdata,int sect)195 static inline u32 sect_to_clust(fsdata *fsdata, int sect)
196 {
197 return (sect - fsdata->data_begin) / fsdata->clust_size;
198 }
199
200 int file_fat_detectfs(void);
201 int fat_exists(const char *filename);
202 int fat_size(const char *filename, loff_t *size);
203 int file_fat_read_at(const char *filename, loff_t pos, void *buffer,
204 loff_t maxsize, loff_t *actread);
205 int file_fat_read(const char *filename, void *buffer, int maxsize);
206 int fat_set_blk_dev(struct blk_desc *rbdd, struct disk_partition *info);
207 int fat_register_device(struct blk_desc *dev_desc, int part_no);
208
209 int file_fat_write(const char *filename, void *buf, loff_t offset, loff_t len,
210 loff_t *actwrite);
211 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len,
212 loff_t *actread);
213 int fat_opendir(const char *filename, struct fs_dir_stream **dirsp);
214 int fat_readdir(struct fs_dir_stream *dirs, struct fs_dirent **dentp);
215 void fat_closedir(struct fs_dir_stream *dirs);
216 int fat_unlink(const char *filename);
217 int fat_mkdir(const char *dirname);
218 void fat_close(void);
219 void *fat_next_cluster(fat_itr *itr, unsigned int *nbytes);
220
221 /**
222 * fat_uuid() - get FAT volume ID
223 *
224 * The FAT volume ID returned in @uuid_str as hexadecimal number in XXXX-XXXX
225 * format.
226 *
227 * @uuid_str: caller allocated buffer of at least 10 bytes for the volume ID
228 * Return: 0 on success
229 */
230 int fat_uuid(char *uuid_str);
231
232 #endif /* _FAT_H_ */
233