b2aa745708
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@223 42af7a65-404d-4744-a932-0658087f49c3
224 lines
10 KiB
C
224 lines
10 KiB
C
/****************************************************************************
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* fs_fat.h
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*
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* Copyright (C) 2007 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name Gregory Nutt nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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#ifndef __FS_FAT_H
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#define __FS_FAT_H
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/types.h>
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#include <semaphore.h>
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/****************************************************************************
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* Definitions
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****************************************************************************/
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/****************************************************************************
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* These offsets describes the master boot record.
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*
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* The folowing fields are common to FAT12/16/32 (but all value descriptions
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* refer to the interpretation under FAT32.
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*/
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#define BS_JUMP 0 /* 3@0: Jump instruction to boot code (ignored) */
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#define BS_OEMNAME 3 /* 8@3: Usually "MSWIN4.1" */
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#define BS_BYTESPERSEC 11 /* 2@11: Bytes per sector: 512, 1024, 2048, 4096 */
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#define BS_SECPERCLUS 13 /* 1@13: Sectors per allocation unit: 2**n, n=0..7 */
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#define BS_RESVDSECCOUNT 14 /* 2@14: Reserved sector count: Usually 32 */
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#define BS_NUMFATS 16 /* 1@16: Number of FAT data structures: always 2 */
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#define BS_ROOTENTCNT 17 /* 2@17: FAT12/16: Must be 0 for FAT32 */
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#define BS_TOTSEC16 19 /* 2@19: FAT12/16: Must be 0, see BS32_totsec32 */
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#define BS_MEDIA 21 /* 1@21: Media code: f0, f8, f9-fa, fc-ff */
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#define BS_FATSZ16 22 /* 2@22: FAT12/16: Must be 0, see BS32_fatsz32 */
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#define BS_SECPERTRK 24 /* 2@24: Sectors per track geometry value */
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#define BS_NUMHEADS 26 /* 2@26: Number of heads geometry value */
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#define BS_HIDSEC 28 /* 4@28: Count of hidden sectors preceding FAT */
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#define BS_TOTSEC32 32 /* 4@32: Total count of sectors on the volume */
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/* The following fields are only valid for FAT12/16 */
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#define BS16_DRVNUM 36 /* 1@36: Drive number for MSDOS bootstrap */
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/* 1@37: Reserverd (zero) */
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#define BS16_BOOTSIG 38 /* 1@38: Extended boot signature: 0x29 if following valid */
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#define BS16_VOLID 39 /* 4@39: Volume serial number */
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#define BS16_VOLLAB 43 /* 11@43: Volume label */
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#define BS16_FILESYSTYPE 54 /* 8@54: "FAT12 ", "FAT16 ", or "FAT " */
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/* The following fields are only valid for FAT32 */
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#define BS32_FATSZ32 36 /* 4@36: Count of sectors occupied by one FAT */
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#define BS32_EXTFLAGS 40 /* 2@40: 0-3:Active FAT, 7=0 both FATS, 7=1 one FAT */
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#define BS32_FSVER 42 /* 2@42: MSB:Major LSB:Minor revision number (0.0) */
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#define BS32_ROOTCLUS 44 /* 4@44: Cluster no. of 1st cluster of root dir */
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#define BS32_FSINFO 48 /* 2@48: Sector number of fsinfo structure. Usually 1. */
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#define BS32_BKBOOTSEC 50 /* 2@50: Sector number of boot record. Usually 6 */
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/* 12@52: Reserved (zero) */
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#define BS32_DRVNUM 64 /* 1@64: Drive number for MSDOS bootstrap */
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/* 1@65: Reserverd (zero) */
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#define BS32_BOOTSIG 66 /* 1@66: Extended boot signature: 0x29 if following valid */
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#define BS32_VOLID 67 /* 4@67: Volume serial number */
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#define BS32_VOLLAB 71 /* 11@71: Volume label */
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#define BS32_FILESYSTYPE 82 /* 8@82: "FAT12 ", "FAT16 ", or "FAT " */
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/* If the sector is not an MBR, then it could have a partition table at
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* this offset.
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*/
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#define MBR_TABLE 446
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/* The magic bytes at the end of the MBR are common to FAT12/16/32 */
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#define BS_SIGNATURE 510 /* 2@510: Valid MBRs have 0x55aa here */
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/* File system types */
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#define FSTYPE_FAT12 0
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#define FSTYPE_FAT16 1
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#define FSTYPE_FAT32 2
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/****************************************************************************
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* These offset describe the FSINFO sector
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*/
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#define FSI_LEADSIG 0 /* 4@0: 0x41615252 */
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/* 480@4: Reserved (zero) */
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#define FSI_STRUCTSIG 484 /* 4@484: 0x61417272 */
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#define FSI_FREECOUNT 488 /* 4@488: Last free cluster count on volume */
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#define FSI_NXTFREE 492 /* 4@492: Cluster number of 1st free cluster */
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/* 12@496: Reserved (zero) */
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#define FSI_TRAILSIG 508 /* 4@508: 0xaa550000 */
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/****************************************************************************
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* Public Types
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****************************************************************************/
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struct fat_direntry_s
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{
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ubyte fde_name[8]; /* name */
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ubyte fde_ext[3]; /* name and extension */
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ubyte fde_attr; /* attribute bits */
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ubyte fde_lcase; /* Case for base and extension */
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ubyte fde_ctimecs; /* Creation time, centiseconds (0-199) */
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ubyte fde_ctime[2]; /* Creation time */
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ubyte fde_cdate[2]; /* Creation date */
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ubyte fde_adate[2]; /* Last access date */
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ubyte fde_starthi[2]; /* High 16 bits of cluster in FAT32 */
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ubyte fde_time[2]; /* Date */
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ubyte fde_date[2]; /* Time */
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ubyte fde_start[2]; /* First cluster */
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ubyte fde_size[4]; /* file size (in bytes) */
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};
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struct fat_dirslot_s
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{
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ubyte fds_id; /* sequence number for slot */
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ubyte fds_name0_4[10]; /* first 5 characters in name */
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ubyte fds_attr; /* attribute byte */
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ubyte fds_reserved; /* always 0 */
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ubyte fds_alias_checksum; /* checksum for 8.3 alias */
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ubyte fds_name5_10[12]; /* 6 more characters in name */
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ubyte fds_start[2]; /* starting cluster number, 0 in long slots */
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ubyte fds_name11_12[4]; /* last 2 characters in name */
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};
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/* This structure represents the overall mountpoint state. An instance of this
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* structure is retained as inode private data on each mountpoint that is
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* mounted with a fat32 filesystem.
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*/
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struct fat_file_s;
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struct fat_mountpt_s
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{
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struct inode *fs_blkdriver; /* The block driver inode that hosts the FAT32 fs */
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struct fat_file_s *fs_head; /* A list to all files opened on this mountpoint */
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boolean fs_mounted; /* TRUE: The file system is ready */
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sem_t fs_sem; /* Used to assume thread-safe access */
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size_t fs_hwsectorsize; /* HW: Sector size reported by block driver*/
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size_t fs_hwnsectors; /* HW: The number of sectors reported by the hardware */
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size_t fs_fatbase; /* Logical block of start of filesystem (past resd sectors) */
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size_t fs_rootbase; /* MBR: Cluster no. of 1st cluster of root dir */
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size_t fs_database; /* Logical block of start data sectors */
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size_t fs_fsinfo; /* MBR: Sector number of FSINFO sector */
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uint32 fs_nclusters; /* Maximum number of data clusters */
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uint32 fs_fatsize; /* MBR: Count of sectors occupied by one fat */
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uint32 fs_fattotsec; /* MBR: Total count of sectors on the volume */
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uint32 fs_fsifreecount; /* FSI: Last free cluster count on volume */
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uint32 fs_fsinextfree; /* FSI: Cluster number of 1st free cluster */
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uint16 fs_fatresvdseccount; /* MBR: The total number of reserved sectors */
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uint16 fs_rootentcnt; /* MBR: Count of 32-bit root directory entries */
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ubyte fs_type; /* FSTYPE_FAT12, FSTYPE_FAT16, or FSTYPE_FAT32 */
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ubyte fs_fatnumfats; /* MBR: Number of FATs (probably 2) */
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ubyte fs_fatsecperclus; /* MBR: Sectors per allocation unit: 2**n, n=0..7 */
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ubyte *fs_buffer; /* This is an allocated buffer to hold one sector
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* from the device */
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};
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/* This structure represents on open file under the mountpoint. An instance of this
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* structure is retained as struct file specific information on each opened file.
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*/
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struct fat_file_s
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{
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struct fat_file_s *ff_next; /* File structures are retained in a singly linked list */
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boolean ff_open; /* TRUE: The file is (still) open */
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};
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/****************************************************************************
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* Global Variables
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****************************************************************************/
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/****************************************************************************
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* Pulblic Function Prototypes
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****************************************************************************/
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#undef EXTERN
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#if defined(__cplusplus)
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#define EXTERN extern "C"
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extern "C" {
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#else
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#define EXTERN extern
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#endif
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#undef EXTERN
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#if defined(__cplusplus)
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}
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#endif
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#endif /* __FS_FAT_H */
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