rockbox/firmware/export/fat.h

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by Linus Nielsen Feltzing
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#ifndef FAT_H
#define FAT_H

#include <stdbool.h>
#include "mv.h" /* for volume definitions */
#include "config.h"
#include "system.h"

/* This value can be overwritten by a target in config-[target].h, but
   that behaviour is still experimental */
#ifndef SECTOR_SIZE
#define SECTOR_SIZE 512
#endif

/* Number of bytes reserved for a file name (including the trailing \0).
   Since names are stored in the entry as UTF-8, we won't be able to
   store all names allowed by FAT. In FAT, a name can have max 255
   characters (not bytes!). Since the UTF-8 encoding of a char may take
   up to 4 bytes, there will be names that we won't be able to store
   completely. For such names, the short DOS name is used. */
#define FAT_FILENAME_BYTES 256

struct fat_direntry
{
    unsigned char name[FAT_FILENAME_BYTES]; /* UTF-8 encoded name plus \0 */
    unsigned short attr;            /* Attributes */
    unsigned char crttimetenth;     /* Millisecond creation
                                       time stamp (0-199) */
    unsigned short crttime;         /* Creation time */
    unsigned short crtdate;         /* Creation date */
    unsigned short lstaccdate;      /* Last access date */
    unsigned short wrttime;         /* Last write time */
    unsigned short wrtdate;         /* Last write date */
    unsigned long filesize;          /* File size in bytes */
    long firstcluster;               /* fstclusterhi<<16 + fstcluslo */
};

#define FAT_ATTR_READ_ONLY   0x01
#define FAT_ATTR_HIDDEN      0x02
#define FAT_ATTR_SYSTEM      0x04
#define FAT_ATTR_VOLUME_ID   0x08
#define FAT_ATTR_DIRECTORY   0x10
#define FAT_ATTR_ARCHIVE     0x20
#define FAT_ATTR_VOLUME      0x40 /* this is a volume, not a real directory */

struct fat_file
{
    long firstcluster;    /* first cluster in file */
    long lastcluster;     /* cluster of last access */
    long lastsector;      /* sector of last access */
    long clusternum;      /* current clusternum */
    long sectornum;       /* sector number in this cluster */
    unsigned int direntry;   /* short dir entry index from start of dir */
    unsigned int direntries; /* number of dir entries used by this file */
    long dircluster;      /* first cluster of dir */
    bool eof;
#ifdef HAVE_MULTIVOLUME
    int volume;          /* file resides on which volume */
#endif
};

struct fat_dir
{
    unsigned char sectorcache[SECTOR_SIZE] CACHEALIGN_ATTR;
    unsigned int entry;
    unsigned int entrycount;
    long sector;
    struct fat_file file;
    /* There are 2-bytes per characters. We don't want to bother too much, as LFN entries are
     * at much 255 characters longs, that's at most 20 LFN entries. Each entry hold at most
     * 13 characters, that a total of 260 characters. So we keep a buffer of that size.
     * Keep coherent with fat.c code. */
    unsigned char longname[260 * 2];
} CACHEALIGN_ATTR;

#ifdef HAVE_HOTSWAP
extern void fat_lock(void);
extern void fat_unlock(void);
#endif

extern void fat_init(void);
extern int fat_get_bytes_per_sector(IF_MV_NONVOID(int volume));
extern int fat_mount(IF_MV2(int volume,) IF_MD2(int drive,) long startsector);
extern int fat_unmount(int volume, bool flush);
extern void fat_size(IF_MV2(int volume,) /* public for info */
                     unsigned long* size,
                     unsigned long* free);
extern void fat_recalc_free(IF_MV_NONVOID(int volume)); /* public for debug info screen */
extern int fat_create_dir(const char* name,
                          struct fat_dir* newdir,
                          struct fat_dir* dir);
extern int fat_open(IF_MV2(int volume,)
                    long cluster,
                    struct fat_file* ent,
                    const struct fat_dir* dir);
extern int fat_create_file(const char* name,
                           struct fat_file* ent,
                           struct fat_dir* dir);
extern long fat_readwrite(struct fat_file *ent, long sectorcount, 
                         void* buf, bool write );
extern int fat_closewrite(struct fat_file *ent, long size, int attr);
extern int fat_seek(struct fat_file *ent, unsigned long sector );
extern int fat_remove(struct fat_file *ent);
extern int fat_truncate(const struct fat_file *ent);
extern int fat_rename(struct fat_file* file, 
                      struct fat_dir* dir,
                      const unsigned char* newname,
                      long size, int attr);

extern int fat_opendir(IF_MV2(int volume,)
                       struct fat_dir *ent, unsigned long startcluster,
                       const struct fat_dir *parent_dir);
extern int fat_getnext(struct fat_dir *ent, struct fat_direntry *entry);
extern unsigned int fat_get_cluster_size(IF_MV_NONVOID(int volume)); /* public for debug info screen */
extern bool fat_ismounted(int volume);
extern void* fat_get_sector_buffer(void);
extern void fat_release_sector_buffer(void);

#endif