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