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/****************************************************************************
* fs_fat.h
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name Gregory Nutt nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
#ifndef __FS_FAT_H
#define __FS_FAT_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <semaphore.h>
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* These offsets describes the master boot record.
*
* The folowing fields are common to FAT12/16/32 (but all value descriptions
* refer to the interpretation under FAT32.
*/
#define BS_JUMP 0 /* 3@0: Jump instruction to boot code (ignored) */
#define BS_OEMNAME 3 /* 8@3: Usually "MSWIN4.1" */
#define BS_BYTESPERSEC 11 /* 2@11: Bytes per sector: 512, 1024, 2048, 4096 */
#define BS_SECPERCLUS 13 /* 1@13: Sectors per allocation unit: 2**n, n=0..7 */
#define BS_RESVDSECCOUNT 14 /* 2@14: Reserved sector count: Usually 32 */
#define BS_NUMFATS 16 /* 1@16: Number of FAT data structures: always 2 */
#define BS_ROOTENTCNT 17 /* 2@17: FAT12/16: Must be 0 for FAT32 */
#define BS_TOTSEC16 19 /* 2@19: FAT12/16: Must be 0, see BS32_totsec32 */
#define BS_MEDIA 21 /* 1@21: Media code: f0, f8, f9-fa, fc-ff */
#define BS_FATSZ16 22 /* 2@22: FAT12/16: Must be 0, see BS32_fatsz32 */
#define BS_SECPERTRK 24 /* 2@24: Sectors per track geometry value */
#define BS_NUMHEADS 26 /* 2@26: Number of heads geometry value */
#define BS_HIDSEC 28 /* 4@28: Count of hidden sectors preceding FAT */
#define BS_TOTSEC32 32 /* 4@32: Total count of sectors on the volume */
/* The following fields are only valid for FAT12/16 */
#define BS16_DRVNUM 36 /* 1@36: Drive number for MSDOS bootstrap */
/* 1@37: Reserverd (zero) */
#define BS16_BOOTSIG 38 /* 1@38: Extended boot signature: 0x29 if following valid */
#define BS16_VOLID 39 /* 4@39: Volume serial number */
#define BS16_VOLLAB 43 /* 11@43: Volume label */
#define BS16_FILESYSTYPE 54 /* 8@54: "FAT12 ", "FAT16 ", or "FAT " */
/* The following fields are only valid for FAT32 */
#define BS32_FATSZ32 36 /* 4@36: Count of sectors occupied by one FAT */
#define BS32_EXTFLAGS 40 /* 2@40: 0-3:Active FAT, 7=0 both FATS, 7=1 one FAT */
#define BS32_FSVER 42 /* 2@42: MSB:Major LSB:Minor revision number (0.0) */
#define BS32_ROOTCLUS 44 /* 4@44: Cluster no. of 1st cluster of root dir */
#define BS32_FSINFO 48 /* 2@48: Sector number of fsinfo structure. Usually 1. */
#define BS32_BKBOOTSEC 50 /* 2@50: Sector number of boot record. Usually 6 */
/* 12@52: Reserved (zero) */
#define BS32_DRVNUM 64 /* 1@64: Drive number for MSDOS bootstrap */
/* 1@65: Reserverd (zero) */
#define BS32_BOOTSIG 66 /* 1@66: Extended boot signature: 0x29 if following valid */
#define BS32_VOLID 67 /* 4@67: Volume serial number */
#define BS32_VOLLAB 71 /* 11@71: Volume label */
#define BS32_FILESYSTYPE 82 /* 8@82: "FAT12 ", "FAT16 ", or "FAT " */
/* If the sector is not an MBR, then it could have a partition table at
* this offset.
*/
#define MBR_TABLE 446
/* The magic bytes at the end of the MBR are common to FAT12/16/32 */
#define BS_SIGNATURE 510 /* 2@510: Valid MBRs have 0x55aa here */
/* File system types */
#define FSTYPE_FAT12 0
#define FSTYPE_FAT16 1
#define FSTYPE_FAT32 2
/****************************************************************************
* These offset describe the FSINFO sector
*/
#define FSI_LEADSIG 0 /* 4@0: 0x41615252 */
/* 480@4: Reserved (zero) */
#define FSI_STRUCTSIG 484 /* 4@484: 0x61417272 */
#define FSI_FREECOUNT 488 /* 4@488: Last free cluster count on volume */
#define FSI_NXTFREE 492 /* 4@492: Cluster number of 1st free cluster */
/* 12@496: Reserved (zero) */
#define FSI_TRAILSIG 508 /* 4@508: 0xaa550000 */
/****************************************************************************
* Public Types
****************************************************************************/
struct fat_direntry_s
{
ubyte fde_name[8]; /* name */
ubyte fde_ext[3]; /* name and extension */
ubyte fde_attr; /* attribute bits */
ubyte fde_lcase; /* Case for base and extension */
ubyte fde_ctimecs; /* Creation time, centiseconds (0-199) */
ubyte fde_ctime[2]; /* Creation time */
ubyte fde_cdate[2]; /* Creation date */
ubyte fde_adate[2]; /* Last access date */
ubyte fde_starthi[2]; /* High 16 bits of cluster in FAT32 */
ubyte fde_time[2]; /* Date */
ubyte fde_date[2]; /* Time */
ubyte fde_start[2]; /* First cluster */
ubyte fde_size[4]; /* file size (in bytes) */
};
struct fat_dirslot_s
{
ubyte fds_id; /* sequence number for slot */
ubyte fds_name0_4[10]; /* first 5 characters in name */
ubyte fds_attr; /* attribute byte */
ubyte fds_reserved; /* always 0 */
ubyte fds_alias_checksum; /* checksum for 8.3 alias */
ubyte fds_name5_10[12]; /* 6 more characters in name */
ubyte fds_start[2]; /* starting cluster number, 0 in long slots */
ubyte fds_name11_12[4]; /* last 2 characters in name */
};
/* This structure represents the overall mountpoint state. An instance of this
* structure is retained as inode private data on each mountpoint that is
* mounted with a fat32 filesystem.
*/
struct fat_file_s;
struct fat_mountpt_s
{
struct inode *fs_blkdriver; /* The block driver inode that hosts the FAT32 fs */
struct fat_file_s *fs_head; /* A list to all files opened on this mountpoint */
boolean fs_mounted; /* TRUE: The file system is ready */
sem_t fs_sem; /* Used to assume thread-safe access */
size_t fs_hwsectorsize; /* HW: Sector size reported by block driver*/
size_t fs_hwnsectors; /* HW: The number of sectors reported by the hardware */
size_t fs_fatbase; /* Logical block of start of filesystem (past resd sectors) */
size_t fs_rootbase; /* MBR: Cluster no. of 1st cluster of root dir */
size_t fs_database; /* Logical block of start data sectors */
size_t fs_fsinfo; /* MBR: Sector number of FSINFO sector */
uint32 fs_nclusters; /* Maximum number of data clusters */
uint32 fs_fatsize; /* MBR: Count of sectors occupied by one fat */
uint32 fs_fattotsec; /* MBR: Total count of sectors on the volume */
uint32 fs_fsifreecount; /* FSI: Last free cluster count on volume */
uint32 fs_fsinextfree; /* FSI: Cluster number of 1st free cluster */
uint16 fs_fatresvdseccount; /* MBR: The total number of reserved sectors */
uint16 fs_rootentcnt; /* MBR: Count of 32-bit root directory entries */
ubyte fs_type; /* FSTYPE_FAT12, FSTYPE_FAT16, or FSTYPE_FAT32 */
ubyte fs_fatnumfats; /* MBR: Number of FATs (probably 2) */
ubyte fs_fatsecperclus; /* MBR: Sectors per allocation unit: 2**n, n=0..7 */
ubyte *fs_buffer; /* This is an allocated buffer to hold one sector
* from the device */
};
/* This structure represents on open file under the mountpoint. An instance of this
* structure is retained as struct file specific information on each opened file.
*/
struct fat_file_s
{
struct fat_file_s *ff_next; /* File structures are retained in a singly linked list */
boolean ff_open; /* TRUE: The file is (still) open */
};
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Pulblic Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __FS_FAT_H */
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