LXR uboot/include/fat.h

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