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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 */
86