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 #define CONFIG_SUPPORT_VFAT 17 /* Maximum Long File Name length supported here is 128 UTF-16 code units */ 18 #define VFAT_MAXLEN_BYTES 256 /* Maximum LFN buffer in bytes */ 19 #define VFAT_MAXSEQ 9 /* Up to 9 of 13 2-byte UTF-16 entries */ 20 #define PREFETCH_BLOCKS 2 21 22 #define MAX_CLUSTSIZE CONFIG_FS_FAT_MAX_CLUSTSIZE 23 24 #define DIRENTSPERBLOCK (mydata->sect_size / sizeof(dir_entry)) 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 typedef struct dir_entry { 136 char name[8],ext[3]; /* Name and extension */ 137 __u8 attr; /* Attribute bits */ 138 __u8 lcase; /* Case for name and ext (CASE_LOWER_x) */ 139 __u8 ctime_ms; /* Creation time, milliseconds */ 140 __u16 ctime; /* Creation time */ 141 __u16 cdate; /* Creation date */ 142 __u16 adate; /* Last access date */ 143 __u16 starthi; /* High 16 bits of cluster in FAT32 */ 144 __u16 time,date,start;/* Time, date and first cluster */ 145 __u32 size; /* File size in bytes */ 146 } dir_entry; 147 148 typedef struct dir_slot { 149 __u8 id; /* Sequence number for slot */ 150 __u8 name0_4[10]; /* First 5 characters in name */ 151 __u8 attr; /* Attribute byte */ 152 __u8 reserved; /* Unused */ 153 __u8 alias_checksum;/* Checksum for 8.3 alias */ 154 __u8 name5_10[12]; /* 6 more characters in name */ 155 __u16 start; /* Unused */ 156 __u8 name11_12[4]; /* Last 2 characters in name */ 157 } dir_slot; 158 159 /* 160 * Private filesystem parameters 161 * 162 * Note: FAT buffer has to be 32 bit aligned 163 * (see FAT32 accesses) 164 */ 165 typedef struct { 166 __u8 *fatbuf; /* Current FAT buffer */ 167 int fatsize; /* Size of FAT in bits */ 168 __u32 fatlength; /* Length of FAT in sectors */ 169 __u16 fat_sect; /* Starting sector of the FAT */ 170 __u8 fat_dirty; /* Set if fatbuf has been modified */ 171 __u32 rootdir_sect; /* Start sector of root directory */ 172 __u16 sect_size; /* Size of sectors in bytes */ 173 __u16 clust_size; /* Size of clusters in sectors */ 174 int data_begin; /* The sector of the first cluster, can be negative */ 175 int fatbufnum; /* Used by get_fatent, init to -1 */ 176 int rootdir_size; /* Size of root dir for non-FAT32 */ 177 __u32 root_cluster; /* First cluster of root dir for FAT32 */ 178 } fsdata; 179 180 static inline u32 clust_to_sect(fsdata *fsdata, u32 clust) 181 { 182 return fsdata->data_begin + clust * fsdata->clust_size; 183 } 184 185 static inline u32 sect_to_clust(fsdata *fsdata, u32 sect) 186 { 187 return (sect - fsdata->data_begin) / fsdata->clust_size; 188 } 189 190 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); 198 199 int file_fat_write(const char *filename, void *buf, loff_t offset, loff_t len, 200 loff_t *actwrite); 201 int fat_read_file(const char *filename, void *buf, loff_t offset, loff_t len, 202 loff_t *actread); 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 void fat_close(void); 207 #endif /* _FAT_H_ */ 208