firmware/fat.h

/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2002 by Linus Nielsen Feltzing
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

#ifndef FAT_H
#define FAT_H

#define FATTYPE_FAT12       0
#define FATTYPE_FAT16       1
#define FATTYPE_FAT32       2

#define BS_JMPBOOT          0
#define BS_OEMNAME          3
#define BPB_BYTSPERSEC      11
#define BPB_SECPERCLUS      13
#define BPB_RSVDSECCNT      14
#define BPB_NUMFATS         16
#define BPB_ROOTENTCNT      17
#define BPB_TOTSEC16        19
#define BPB_MEDIA           21
#define BPB_FATSZ16         22
#define BPB_SECPERTRK       24
#define BPB_NUMHEADS        26
#define BPB_HIDDSEC         28
#define BPB_TOTSEC32        32

#define BS_DRVNUM           36
#define BS_RESERVED1        37
#define BS_BOOTSIG          38
#define BS_VOLID            39
#define BS_VOLLAB           43
#define BS_FILSYSTYPE       54

#define BPB_FATSZ32          36

#define BPB_LAST_WORD       510

#define MIN(a,b) (((a) < (b))?(a):(b)))

struct bpb
{
        char bs_oemname[9];  /* OEM string, ending with \0 */
        int bpb_bytspersec;  /* Bytes per sectory, typically 512 */
        int bpb_secperclus;  /* Sectors per cluster */
        int bpb_rsvdseccnt;  /* Number of reserved sectors */
        int bpb_numfats;     /* Number of FAT structures, typically 2 */
        int bpb_rootentcnt;  /* Number of dir entries in the root */
        int bpb_totsec16;    /* Number of sectors on the volume (old 16-bit) */
        int bpb_media;       /* Media type (typically 0xf0 or 0xf8) */
        int bpb_fatsz16;     /* Number of used sectors per FAT structure */
        int bpb_secpertrk;   /* Number of sectors per track */
        int bpb_numheads;    /* Number of heads */
        int bpb_hiddsec;     /* Hidden sectors before the volume */
        unsigned int bpb_totsec32;    /* Number of sectors on the volume
                                         (new 32-bit) */
        /**** FAT12/16 specific *****/
        int bs_drvnum;       /* Drive number */
        int bs_bootsig;      /* Is 0x29 if the following 3 fields are valid */
        unsigned int bs_volid; /* Volume ID */
        char bs_vollab[12];  /* Volume label, 11 chars plus \0 */
        char bs_filsystype[9]; /* File system type, 8 chars plus \0 */

        /**** FAT32 specific *****/
        int bpb_fatsz32;
        
        int last_word;       /* Must be 0xaa55 */

        int fat_type;        /* What type of FAT is this? */
};

#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_LONG_NAME   (FAT_ATTR_READ_ONLY | FAT_ATTR_HIDDEN | \
                              FAT_ATTR_SYSTEM | FAT_ATTR_VOLUME_ID)


#define FATDIR_NAME          0
#define FATDIR_ATTR          11
#define FATDIR_NTRES         12
#define FATDIR_CRTTIMETENTH  13
#define FATDIR_CRTTIME       14
#define FATDIR_CRTDATE       16
#define FATDIR_LSTACCDATE    18
#define FATDIR_FSTCLUSHI     20
#define FATDIR_WRTTIME       22
#define FATDIR_WRTDATE       24
#define FATDIR_FSTCLUSLO     26
#define FATDIR_FILESIZE      28

struct fat_direntry
{
        unsigned char name[12];         /* 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 fstclushi;       /* High word of first cluster
                                           (0 for FAT12/16) */
        unsigned short wrttime;         /* Last write time */
        unsigned short wrtdate;         /* Last write date */
        unsigned short fstcluslo;       /* Low word of first cluster */
        unsigned int filesize;          /* File size in bytes */
};

struct fat_context
{
        unsigned int curr_dir_sec; /* Current directory sector */
        
};

struct disk_info
{
        int num_sectors;
        int sec_per_track;
        int num_heads;
        unsigned int hidden_sectors;
};

struct fat_dirent
{
        int entry;
        unsigned int cached_sec;
        unsigned int num_sec;
        char cached_buf[BLOCK_SIZE];
};

int fat_format(struct disk_info *di, char *vol_name);
int fat_create_file(struct bpb *bpb, unsigned int currdir, char *name);
int fat_opendir(struct bpb *bpb, struct fat_dirent *ent, unsigned int currdir);
int fat_getnext(struct bpb *bpb, struct fat_dirent *ent,
                struct fat_direntry *entry);

#endif