libfat/libfat.h

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2004-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8  *   Boston MA 02111-1307, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 /*
  14  * libfat.h
  15  *
  16  * Headers for the libfat library
  17  */
  18
  19 #ifndef LIBFAT_H
  20 #define LIBFAT_H
  21
  22 #include <stddef.h>
  23 #include <inttypes.h>
  24
  25 #define LIBFAT_SECTOR_SHIFT     9
  26 #define LIBFAT_SECTOR_SIZE      512
  27 #define LIBFAT_SECTOR_MASK      511
  28
  29 typedef uint64_t libfat_sector_t;
  30 struct libfat_filesystem;
  31
  32 struct libfat_direntry {
  33     libfat_sector_t sector;
  34     int offset;
  35     unsigned char entry[32];
  36 };
  37
  38 /*
  39  * Open the filesystem.  The readfunc is the function to read
  40  * sectors, in the format:
  41  * int readfunc(intptr_t readptr, void *buf, size_t secsize,
  42  *              libfat_sector_t secno)
  43  *
  44  * ... where readptr is a private argument.
  45  *
  46  * A return value of != secsize is treated as error.
  47  */
  48 struct libfat_filesystem
  49     *libfat_open(int (*readfunc) (intptr_t, void *, size_t, libfat_sector_t),
  50                  intptr_t readptr);
  51
  52 void libfat_close(struct libfat_filesystem *);
  53
  54 /*
  55  * Convert a cluster number (or 0 for the root directory) to a
  56  * sector number.  Return -1 on failure.
  57  */
  58 libfat_sector_t libfat_clustertosector(const struct libfat_filesystem *fs,
  59                                        int32_t cluster);
  60
  61 /*
  62  * Get the next sector of either the root directory or a FAT chain.
  63  * Returns 0 on end of file and -1 on error.
  64  */
  65 libfat_sector_t libfat_nextsector(struct libfat_filesystem *fs,
  66                                   libfat_sector_t s);
  67
  68 /*
  69  * Flush all cached sectors for this filesystem.
  70  */
  71 void libfat_flush(struct libfat_filesystem *fs);
  72
  73 /*
  74  * Get a pointer to a specific sector.
  75  */
  76 void *libfat_get_sector(struct libfat_filesystem *fs, libfat_sector_t n);
  77
  78 /*
  79  * Search a FAT directory for a particular pre-mangled filename.
  80  * Copies the directory entry into direntry and returns 0 if found.
  81  */
  82 int32_t libfat_searchdir(struct libfat_filesystem *fs, int32_t dirclust,
  83                          const void *name, struct libfat_direntry *direntry);
  84
  85 #endif /* LIBFAT_H */