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  * See file CREDITS for list of people who contributed to this
   8  * project.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of
  13  * the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23  * MA 02111-1307 USA
  24  *
  25  */
  26
  27 #ifndef _FAT_H_
  28 #define _FAT_H_
  29
  30 #include <asm/byteorder.h>
  31
  32 #define CONFIG_SUPPORT_VFAT
  33 /* Maximum Long File Name length supported here is 128 UTF-16 code units */
  34 #define VFAT_MAXLEN_BYTES       256 /* Maximum LFN buffer in bytes */
  35 #define VFAT_MAXSEQ             9   /* Up to 9 of 13 2-byte UTF-16 entries */
  36 #define PREFETCH_BLOCKS         2
  37
  38 #define MAX_CLUSTSIZE   65536
  39 #define DIRENTSPERBLOCK (mydata->sect_size / sizeof(dir_entry))
  40 #define DIRENTSPERCLUST ((mydata->clust_size * mydata->sect_size) / \
  41                          sizeof(dir_entry))
  42
  43 #define FATBUFBLOCKS    6
  44 #define FATBUFSIZE      (mydata->sect_size * FATBUFBLOCKS)
  45 #define FAT12BUFSIZE    ((FATBUFSIZE*2)/3)
  46 #define FAT16BUFSIZE    (FATBUFSIZE/2)
  47 #define FAT32BUFSIZE    (FATBUFSIZE/4)
  48
  49
  50 /* Filesystem identifiers */
  51 #define FAT12_SIGN      "FAT12   "
  52 #define FAT16_SIGN      "FAT16   "
  53 #define FAT32_SIGN      "FAT32   "
  54 #define SIGNLEN         8
  55
  56 /* File attributes */
  57 #define ATTR_RO 1
  58 #define ATTR_HIDDEN     2
  59 #define ATTR_SYS        4
  60 #define ATTR_VOLUME     8
  61 #define ATTR_DIR        16
  62 #define ATTR_ARCH       32
  63
  64 #define ATTR_VFAT       (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)
  65
  66 #define DELETED_FLAG    ((char)0xe5) /* Marks deleted files when in name[0] */
  67 #define aRING           0x05         /* Used as special character in name[0] */
  68
  69 /*
  70  * Indicates that the entry is the last long entry in a set of long
  71  * dir entries
  72  */
  73 #define LAST_LONG_ENTRY_MASK    0x40
  74
  75 /* Flags telling whether we should read a file or list a directory */
  76 #define LS_NO           0
  77 #define LS_YES          1
  78 #define LS_DIR          1
  79 #define LS_ROOT         2
  80
  81 #define ISDIRDELIM(c)   ((c) == '/' || (c) == '\\')
  82
  83 #define FSTYPE_NONE     (-1)
  84
  85 #if defined(__linux__) && defined(__KERNEL__)
  86 #define FAT2CPU16       le16_to_cpu
  87 #define FAT2CPU32       le32_to_cpu
  88 #else
  89 #if __LITTLE_ENDIAN
  90 #define FAT2CPU16(x)    (x)
  91 #define FAT2CPU32(x)    (x)
  92 #else
  93 #define FAT2CPU16(x)    ((((x) & 0x00ff) << 8) | (((x) & 0xff00) >> 8))
  94 #define FAT2CPU32(x)    ((((x) & 0x000000ff) << 24)  |  \
  95                          (((x) & 0x0000ff00) << 8)  |   \
  96                          (((x) & 0x00ff0000) >> 8)  |   \
  97                          (((x) & 0xff000000) >> 24))
  98 #endif
  99 #endif
 100
 101 #define START(dent)     (FAT2CPU16((dent)->start) \
 102                         + (mydata->fatsize != 32 ? 0 : \
 103                           (FAT2CPU16((dent)->starthi) << 16)))
 104 #define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
 105                                 (x) >= ((fatsize) != 32 ? 0xfff0 : 0xffffff0))
 106
 107 typedef struct boot_sector {
 108         __u8    ignored[3];     /* Bootstrap code */
 109         char    system_id[8];   /* Name of fs */
 110         __u8    sector_size[2]; /* Bytes/sector */
 111         __u8    cluster_size;   /* Sectors/cluster */
 112         __u16   reserved;       /* Number of reserved sectors */
 113         __u8    fats;           /* Number of FATs */
 114         __u8    dir_entries[2]; /* Number of root directory entries */
 115         __u8    sectors[2];     /* Number of sectors */
 116         __u8    media;          /* Media code */
 117         __u16   fat_length;     /* Sectors/FAT */
 118         __u16   secs_track;     /* Sectors/track */
 119         __u16   heads;          /* Number of heads */
 120         __u32   hidden;         /* Number of hidden sectors */
 121         __u32   total_sect;     /* Number of sectors (if sectors == 0) */
 122
 123         /* FAT32 only */
 124         __u32   fat32_length;   /* Sectors/FAT */
 125         __u16   flags;          /* Bit 8: fat mirroring, low 4: active fat */
 126         __u8    version[2];     /* Filesystem version */
 127         __u32   root_cluster;   /* First cluster in root directory */
 128         __u16   info_sector;    /* Filesystem info sector */
 129         __u16   backup_boot;    /* Backup boot sector */
 130         __u16   reserved2[6];   /* Unused */
 131 } boot_sector;
 132
 133 typedef struct volume_info
 134 {
 135         __u8 drive_number;      /* BIOS drive number */
 136         __u8 reserved;          /* Unused */
 137         __u8 ext_boot_sign;     /* 0x29 if fields below exist (DOS 3.3+) */
 138         __u8 volume_id[4];      /* Volume ID number */
 139         char volume_label[11];  /* Volume label */
 140         char fs_type[8];        /* Typically FAT12, FAT16, or FAT32 */
 141         /* Boot code comes next, all but 2 bytes to fill up sector */
 142         /* Boot sign comes last, 2 bytes */
 143 } volume_info;
 144
 145 typedef struct dir_entry {
 146         char    name[8],ext[3]; /* Name and extension */
 147         __u8    attr;           /* Attribute bits */
 148         __u8    lcase;          /* Case for base and extension */
 149         __u8    ctime_ms;       /* Creation time, milliseconds */
 150         __u16   ctime;          /* Creation time */
 151         __u16   cdate;          /* Creation date */
 152         __u16   adate;          /* Last access date */
 153         __u16   starthi;        /* High 16 bits of cluster in FAT32 */
 154         __u16   time,date,start;/* Time, date and first cluster */
 155         __u32   size;           /* File size in bytes */
 156 } dir_entry;
 157
 158 typedef struct dir_slot {
 159         __u8    id;             /* Sequence number for slot */
 160         __u8    name0_4[10];    /* First 5 characters in name */
 161         __u8    attr;           /* Attribute byte */
 162         __u8    reserved;       /* Unused */
 163         __u8    alias_checksum;/* Checksum for 8.3 alias */
 164         __u8    name5_10[12];   /* 6 more characters in name */
 165         __u16   start;          /* Unused */
 166         __u8    name11_12[4];   /* Last 2 characters in name */
 167 } dir_slot;
 168
 169 /*
 170  * Private filesystem parameters
 171  *
 172  * Note: FAT buffer has to be 32 bit aligned
 173  * (see FAT32 accesses)
 174  */
 175 typedef struct {
 176         __u8    *fatbuf;        /* Current FAT buffer */
 177         int     fatsize;        /* Size of FAT in bits */
 178         __u32   fatlength;      /* Length of FAT in sectors */
 179         __u16   fat_sect;       /* Starting sector of the FAT */
 180         __u32   rootdir_sect;   /* Start sector of root directory */
 181         __u16   sect_size;      /* Size of sectors in bytes */
 182         __u16   clust_size;     /* Size of clusters in sectors */
 183         int     data_begin;     /* The sector of the first cluster, can be negative */
 184         int     fatbufnum;      /* Used by get_fatent, init to -1 */
 185 } fsdata;
 186
 187 typedef int     (file_detectfs_func)(void);
 188 typedef int     (file_ls_func)(const char *dir);
 189 typedef long    (file_read_func)(const char *filename, void *buffer,
 190                                  unsigned long maxsize);
 191
 192 struct filesystem {
 193         file_detectfs_func      *detect;
 194         file_ls_func            *ls;
 195         file_read_func          *read;
 196         const char              name[12];
 197 };
 198
 199 /* FAT tables */
 200 file_detectfs_func      file_fat_detectfs;
 201 file_ls_func            file_fat_ls;
 202 file_read_func          file_fat_read;
 203
 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 long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
 209                       unsigned long maxsize);
 210 long file_fat_read(const char *filename, void *buffer, unsigned long maxsize);
 211 const char *file_getfsname(int idx);
 212 int fat_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info);
 213 int fat_register_device(block_dev_desc_t *dev_desc, int part_no);
 214
 215 int file_fat_write(const char *filename, void *buffer, unsigned long maxsize);
 216 #endif /* _FAT_H_ */