source: mainline/uspace/lib/label/include/std/fat.h

/*
 * Copyright (c) 2008 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup liblabel
 * @{
 */

#ifndef FAT_FAT_H_
#define FAT_FAT_H_

#include <stdint.h>

#define BS_BLOCK                0
#define BS_SIZE                 512
#define DIRENT_SIZE             32

#define FAT12_CLST_MAX    4085
#define FAT16_CLST_MAX    65525

#define FATAUTO 0
#define FAT12   12
#define FAT16   16
#define FAT32   32

#define FAT_CLUSTER_DOUBLE_SIZE(a) ((a) / 4)

typedef struct fat_bs {
        /** Jump instruction */
        uint8_t         ji[3];
        uint8_t         oem_name[8];

        /* BIOS Parameter Block */

        /** Bytes per sector */
        uint16_t        bps;
        /** Sectors per cluster */
        uint8_t         spc;
        /** Reserved sector count */
        uint16_t        rscnt;
        /** Number of FATs */
        uint8_t         fatcnt;
        /** Maximum number of root directory entries */
        uint16_t        root_ent_max;
        /** Total sectors. 16-bit version */
        uint16_t        totsec16;
        /** Media descriptor */
        uint8_t         mdesc;
        /** Sectors per FAT12/FAT16 */
        uint16_t        sec_per_fat;
        /** Sectors per track */
        uint16_t        sec_per_track;
        /** Number of heads */
        uint16_t        headcnt;
        /** Hidden sectors */
        uint32_t        hidden_sec;
        /** Total sectors. 32-bit version */
        uint32_t        totsec32;

        union {
                struct {
                        /* FAT12/FAT16 only: Extended BIOS Parameter Block */
                        /** Physical drive number. */
                        uint8_t         pdn;
                        uint8_t         reserved;
                        /** Extended boot signature. */
                        uint8_t         ebs;
                        /** Serial number. */
                        uint32_t        id;
                        /** Volume label. */
                        uint8_t         label[11];
                        /** FAT type. */
                        uint8_t         type[8];
                        /** Boot code. */
                        uint8_t         boot_code[448];
                        /** Boot sector signature. */
                        uint16_t        signature;
                } __attribute__((packed));
                struct {
                        /* FAT32 only */
                        /** Sectors per FAT. */
                        uint32_t        sectors_per_fat;
                        /** FAT flags. */
                        uint16_t        flags;
                        /** Version. */
                        uint16_t        version;
                        /** Cluster number of root directory. */
                        uint32_t        root_cluster;
                        /** Sector number of file system information sector. */
                        uint16_t        fsinfo_sec;
                        /** Sector number of boot sector copy. */
                        uint16_t        bscopy_sec;
                        uint8_t         reserved1[12];
                        /** Physical drive number. */
                        uint8_t         pdn;
                        uint8_t         reserved2;
                        /** Extended boot signature. */
                        uint8_t         ebs;
                        /** Serial number. */
                        uint32_t        id;
                        /** Volume label. */
                        uint8_t         label[11];
                        /** FAT type. */
                        uint8_t         type[8];
                        /** Boot code. */
                        uint8_t         boot_code[420];
                        /** Signature. */
                        uint16_t        signature;
                } __attribute__((packed)) fat32;
        };
} __attribute__((packed)) fat_bs_t;

#endif

/**
 * @}
 */