include/fat.h

   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
  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
  20
  21 #define MAX_CLUSTSIZE   65536
  22 #define DIRENTSPERBLOCK (mydata->sect_size / sizeof(dir_entry))
  23 #define DIRENTSPERCLUST ((mydata->clust_size * mydata->sect_size) / \
  24                          sizeof(dir_entry))
  25
  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)
  31
  32
  33 /* Filesystem identifiers */
  34 #define FAT12_SIGN      "FAT12   "
  35 #define FAT16_SIGN      "FAT16   "
  36 #define FAT32_SIGN      "FAT32   "
  37 #define SIGNLEN         8
  38
  39 /* File attributes */
  40 #define ATTR_RO 1
  41 #define ATTR_HIDDEN     2
  42 #define ATTR_SYS        4
  43 #define ATTR_VOLUME     8
  44 #define ATTR_DIR        16
  45 #define ATTR_ARCH       32
  46
  47 #define ATTR_VFAT       (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
  48
  49 #define DELETED_FLAG    ((char)0xe5) /* Marks deleted files when in name[0] */
  50 #define aRING           0x05         /* Used as special character in name[0] */
  51
  52 /*
  53  * Indicates that the entry is the last long entry in a set of long
  54  * dir entries
  55  */
  56 #define LAST_LONG_ENTRY_MASK    0x40
  57
  58 /* Flags telling whether we should read a file or list a directory */
  59 #define LS_NO           0
  60 #define LS_YES          1
  61 #define LS_DIR          1
  62 #define LS_ROOT         2
  63
  64 #define ISDIRDELIM(c)   ((c) == '/' || (c) == '\\')
  65
  66 #define FSTYPE_NONE     (-1)
  67
  68 #if defined(__linux__) && defined(__KERNEL__)
  69 #define FAT2CPU16       le16_to_cpu
  70 #define FAT2CPU32       le32_to_cpu
  71 #else
  72 #if __LITTLE_ENDIAN
  73 #define FAT2CPU16(x)    (x)
  74 #define FAT2CPU32(x)    (x)
  75 #else
  76 #define FAT2CPU16(x)    ((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
  77 #define FAT2CPU32(x)    ((((x) & 0x000000ff) << 24)  |  \
  78                          (((x) & 0x0000ff00) << 8)  |   \
  79                          (((x) & 0x00ff0000) >> 8)  |   \
  80                          (((x) & 0xff000000) >> 24))
  81 #endif
  82 #endif
  83
  84 #define START(dent)     (FAT2CPU16((dent)->start) \
  85                         + (mydata->fatsize != 32 ? 0 : \
  86                           (FAT2CPU16((dent)->starthi) << 16)))
  87 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
  88                                 (x) >= ((fatsize) != 32 ? 0xfff0 : 0xffffff0))
  89
  90 typedef struct boot_sector {
  91         __u8    ignored[3];     /* Bootstrap code */
  92         char    system_id[8];   /* Name of fs */
  93         __u8    sector_size[2]; /* Bytes/sector */
  94         __u8    cluster_size;   /* Sectors/cluster */
  95         __u16   reserved;       /* Number of reserved sectors */
  96         __u8    fats;           /* Number of FATs */
  97         __u8    dir_entries[2]; /* Number of root directory entries */
  98         __u8    sectors[2];     /* Number of sectors */
  99         __u8    media;          /* Media code */
 100         __u16   fat_length;     /* Sectors/FAT */
 101         __u16   secs_track;     /* Sectors/track */
 102         __u16   heads;          /* Number of heads */
 103         __u32   hidden;         /* Number of hidden sectors */
 104         __u32   total_sect;     /* Number of sectors (if sectors == 0) */
 105
 106         /* FAT32 only */
 107         __u32   fat32_length;   /* Sectors/FAT */
 108         __u16   flags;          /* Bit 8: fat mirroring, low 4: active fat */
 109         __u8    version[2];     /* Filesystem version */
 110         __u32   root_cluster;   /* First cluster in root directory */
 111         __u16   info_sector;    /* Filesystem info sector */
 112         __u16   backup_boot;    /* Backup boot sector */
 113         __u16   reserved2[6];   /* Unused */
 114 } boot_sector;
 115
 116 typedef struct volume_info
 117 {
 118         __u8 drive_number;      /* BIOS drive number */
 119         __u8 reserved;          /* Unused */
 120         __u8 ext_boot_sign;     /* 0x29 if fields below exist (DOS 3.3+) */
 121         __u8 volume_id[4];      /* Volume ID number */
 122         char volume_label[11];  /* Volume label */
 123         char fs_type[8];        /* Typically FAT12, FAT16, or FAT32 */
 124         /* Boot code comes next, all but 2 bytes to fill up sector */
 125         /* Boot sign comes last, 2 bytes */
 126 } volume_info;
 127
 128 typedef struct dir_entry {
 129         char    name[8],ext[3]; /* Name and extension */
 130         __u8    attr;           /* Attribute bits */
 131         __u8    lcase;          /* Case for base and extension */
 132         __u8    ctime_ms;       /* Creation time, milliseconds */
 133         __u16   ctime;          /* Creation time */
 134         __u16   cdate;          /* Creation date */
 135         __u16   adate;          /* Last access date */
 136         __u16   starthi;        /* High 16 bits of cluster in FAT32 */
 137         __u16   time,date,start;/* Time, date and first cluster */
 138         __u32   size;           /* File size in bytes */
 139 } dir_entry;
 140
 141 typedef struct dir_slot {
 142         __u8    id;             /* Sequence number for slot */
 143         __u8    name0_4[10];    /* First 5 characters in name */
 144         __u8    attr;           /* Attribute byte */
 145         __u8    reserved;       /* Unused */
 146         __u8    alias_checksum;/* Checksum for 8.3 alias */
 147         __u8    name5_10[12];   /* 6 more characters in name */
 148         __u16   start;          /* Unused */
 149         __u8    name11_12[4];   /* Last 2 characters in name */
 150 } dir_slot;
 151
 152 /*
 153  * Private filesystem parameters
 154  *
 155  * Note: FAT buffer has to be 32 bit aligned
 156  * (see FAT32 accesses)
 157  */
 158 typedef struct {
 159         __u8    *fatbuf;        /* Current FAT buffer */
 160         int     fatsize;        /* Size of FAT in bits */
 161         __u32   fatlength;      /* Length of FAT in sectors */
 162         __u16   fat_sect;       /* Starting sector of the FAT */
 163         __u32   rootdir_sect;   /* Start sector of root directory */
 164         __u16   sect_size;      /* Size of sectors in bytes */
 165         __u16   clust_size;     /* Size of clusters in sectors */
 166         int     data_begin;     /* The sector of the first cluster, can be negative */
 167         int     fatbufnum;      /* Used by get_fatent, init to -1 */
 168 } fsdata;
 169
 170 typedef int     (file_detectfs_func)(void);
 171 typedef int     (file_ls_func)(const char *dir);
 172 typedef long    (file_read_func)(const char *filename, void *buffer,
 173                                  unsigned long maxsize);
 174
 175 struct filesystem {
 176         file_detectfs_func      *detect;
 177         file_ls_func            *ls;
 178         file_read_func          *read;
 179         const char              name[12];
 180 };
 181
 182 /* FAT tables */
 183 file_detectfs_func      file_fat_detectfs;
 184 file_ls_func            file_fat_ls;
 185 file_read_func          file_fat_read;
 186
 187 /* Currently this doesn't check if the dir exists or is valid... */
 188 int file_cd(const char *path);
 189 int file_fat_detectfs(void);
 190 int file_fat_ls(const char *dir);
 191 long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
 192                       unsigned long maxsize);
 193 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize);
 194 const char *file_getfsname(int idx);
 195 int fat_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info);
 196 int fat_register_device(block_dev_desc_t *dev_desc, int part_no);
 197
 198 int file_fat_write(const char *filename, void *buffer, unsigned long maxsize);
 199 int fat_read_file(const char *filename, void *buf, int offset, int len);
 200 void fat_close(void);
 201 #endif /* _FAT_H_ */