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nuttx/fs/fs_fat32.h
patacongo 4074b03ff7 FAT read logic integrated 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@237 42af7a65-404d-4744-a932-0658087f49c3
2007-05-20 16:58:37 +00:00

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/****************************************************************************
* fs_fat32.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 */
/****************************************************************************
* Each FAT directory entry is 32-bytes long. The following define offsets
* relative to the beginning of a directory entry.
*/
#define DIR_NAME 0 /* 11@ 0: NAME: 8 bytes + 3 byte extension */
#define DIR_ATTRIBUTES 11 /* 1@11: File attibutes (see below) */
#define DIR_NTRES 12 /* 1@12: Reserved for use by NT */
#define DIR_CRTTIMETENTH 13 /* 1@13: Tenth sec creation timestamp */
#define DIR_CRTIME 14 /* 2@14: Time file created */
#define DIR_CRDATE 16 /* 2@16: Date file created */
#define DIR_LASTACCDATE 18 /* 2@19: Last access date */
#define DIR_FSTCLUSTHI 20 /* 2@20: MS first cluster number */
#define DIR_WRTTIME 22 /* 2@22: Time of last write */
#define DIR_WRTDATE 24 /* 2@24: Date of last write */
#define DIR_FSTCLUSTLO 26 /* 2@26: LS first cluster number */
#define DIR_FILESIZE 28 /* 4@28: File size in bytes */
/* First byte of the directory name has special meanings: */
#define DIR0_EMPTY 0xe5 /* The directory entry is empty */
#define DIR0_ALLEMPTY 0x00 /* This entry and all following are empty */
#define DIR0_E5 0x05 /* The actual value is 0xe5 */
/* NTRES flags in the FAT directory */
#define FATNTRES_LCNAME 0x08 /* Lower case in name */
#define FATNTRES_LCEXT 0x10 /* Lower case in extension */
/* File attribute bits in FAT directory entry */
#define FATATTR_READONLY 0x01
#define FATATTR_HIDDEN 0x02
#define FATATTR_SYSTEM 0x04
#define FATATTR_VOLUMEID 0x08
#define FATATTR_DIRECTORY 0x10
#define FATATTR_ARCHIVE 0x20
#define FATATTR_LONGNAME \
(FATATTR_READONLY|FATATTR_HIDDEN|FATATTR_SYSTEM|FATATTR_VOLUMEID)
/* Directory indexing helper. Each directory entry is 32-bytes in length.
* The number of directory entries in a sector then varies with the size
* of the sector supported in hardware.
*/
#define DIRSEC_NDXMASK(f) (((f)->fs_hwsectorsize - 1) >> 5)
#define DIRSEC_NDIRS(f) (((f)->fs_hwsectorsize) >> 5)
#define DIRSEC_BYTENDX(f,i) (((i) & DIRSEC_NDXMASK(fs)) << 5)
#define SEC_NDXMASK(f) ((f)->fs_hwsectorsize - 1)
#define SEC_NSECTORS(f,n) ((n) / (f)->fs_hwsectorsize)
/****************************************************************************
* File system types */
#define FSTYPE_FAT12 0
#define FSTYPE_FAT16 1
#define FSTYPE_FAT32 2
/* File buffer flags */
#define FFBUFF_VALID 1
#define FFBUFF_DIRTY 2
#define FFBUFF_MODIFIED 4
/****************************************************************************
* 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 */
/****************************************************************************
* Access to data in raw sector data */
#define UBYTE_VAL(p,o) (((ubyte*)(p))[o])
#define UBYTE_PTR(p,o) &UBYTE_VAL(p,o)
#define UBYTE_PUT(p,o,v) (UBYTE_VAL(p,o)=(ubyte)(v))
#define UINT16_PTR(p,o) ((uint16*)UBYTE_PTR(p,o))
#define UINT16_VAL(p,o) (*UINT16_PTR(p,o))
#define UINT16_PUT(p,o,v) (UINT16_VAL(p,o)=(uint16)(v))
#define UINT32_PTR(p,o) ((uint32*)UBYTE_PTR(p,o))
#define UINT32_VAL(p,o) (*UINT32_PTR(p,o))
#define UINT32_PUT(p,o,v) (UINT32_VAL(p,o)=(uint32)(v))
/* Regardless of the endian-ness of the target or alignment of the data, no
* special operations are required for byte, string or byte array accesses.
* The FAT data stream is little endian so multiple byte values must be
* accessed byte-by-byte for big-endian targets.
*/
#define MBR_GETSECPERCLUS(p) UBYTE_VAL(p,BS_SECPERCLUS)
#define MBR_GETNUMFATS(p) UBYTE_VAL(p,BS_NUMFATS)
#define MBR_GETMEDIA(p) UBYTE_VAL(p,BS_MEDIA)
#define MBR_GETDRVNUM16(p) UBYTE_VAL(p,BS16_DRVNUM)
#define MBR_GETDRVNUM32(p) UBYTE_VAL(p,BS32_DRVNUM)
#define MBR_GETBOOTSIG16(p) UBYTE_VAL(p,BS16_BOOTSIG)
#define MBR_GETBOOTSIG32(p) UBYTE_VAL(p,BS32_BOOTSIG)
#define DIR_GETATTRIBUTES(p) UBYTE_VAL(p,DIR_ATTRIBUTES)
#define DIR_GETNTRES(p) UBYTE_VAL(p,DIR_NTRES)
#define DIR_GETCRTTIMETENTH(p) UBYTE_VAL(p,DIR_CRTTIMETENTH)
#define MBR_PUTSECPERCLUS(p,v) UBYTE_PUT(p,BS_SECPERCLUS),v)
#define MBR_PUTNUMFATS(p,v) UBYTE_PUT(p,BS_NUMFATS,v)
#define MBR_PUTMEDIA(p,v) UBYTE_PUT(p,BS_MEDIA,v)
#define MBR_PUTDRVNUM16(p,v) UBYTE_PUT(p,BS16_DRVNUM,v)
#define MBR_PUTDRVNUM32(p,v) UBYTE_PUT(p,BS32_DRVNUM,v)
#define MBR_PUTBOOTSIG16(p,v) UBYTE_PUT(p,BS16_BOOTSIG,v)
#define MBR_PUTBOOTSIG32(p,v) UBYTE_PUT(p,BS32_BOOTSIG,v)
#define DIR_PUTATTRIBUTES(p,v) UBYTE_PUT(p,DIR_ATTRIBUTES,v)
#define DIR_PUTNTRES(p,v) UBYTE_PUT(p,DIR_NTRES,v)
#define DIR_PUTCRTTIMETENTH(p,v) UBYTE_PUT(p,DIR_CRTTIMETENTH,v)
/* For the all targets, unaligned values need to be accessed byte-by-byte.
* Some architectures may handle unaligned accesses with special interrupt
* handlers. But even in that case, it is more efficient to avoid the traps.
*/
/* Unaligned multi-byte access macros */
#define MBR_GETBYTESPERSEC(p) fat_getuint16(UBYTE_PTR(p,BS_BYTESPERSEC))
#define MBR_GETROOTENTCNT(p) fat_getuint16(UBYTE_PTR(p,BS_ROOTENTCNT))
#define MBR_GETTOTSEC16(p) fat_getuint16(UBYTE_PTR(p,BS_TOTSEC16))
#define MBR_GETVOLID16(p) fat_getuint32(UBYTE_PTR(p,BS16_VOLID))
#define MBR_GETVOLID32(p) fat_getuint32(UBYTE_PTR(p,BS32_VOLID))
#define MBR_PUTBYTESPERSEC(p,v) fat_putuint16(UBYTE_PTR(p,BS_BYTESPERSEC),v)
#define MBR_PUTROOTENTCNT(p,v) fat_putuint16(UBYTE_PTR(p,BS_ROOTENTCNT),v)
#define MBR_PUTTOTSEC16(p,v) fat_putuint16(UBYTE_PTR(p,BS_TOTSEC16),v)
#define MBR_PUTVOLID16(p,v) fat_putuint32(UBYTE_PTR(p,BS16_VOLID),v)
#define MBR_PUTVOLID32(p,v) fat_putuint32(UBYTE_PTR(p,BS32_VOLID),v)
/* But for multi-byte values, the endian-ness of the target vs. the little
* endian order of the byte stream or alignment of the data within the byte
* stream can force special, byte-by-byte accesses.
*/
#ifdef CONFIG_ARCH_BIGENDIAN
/* If the target is big-endian, then even aligned multi-byte values must be
* accessed byte-by-byte.
*/
# define MBR_GETRESVDSECCOUNT(p) fat_getuint16(UBYTE_PTR(p,BS_RESVDSECCOUNT))
# define MBR_GETFATSZ16(p) fat_getuint16(UBYTE_PTR(p,BS_FATSZ16))
# define MBR_GETSECPERTRK(p) fat_getuint16(UBYTE_PTR(p,BS_SECPERTRK))
# define MBR_GETNUMHEADS(p) fat_getuint16(UBYTE_PTR(p,BS_NUMHEADS))
# define MBR_GETHIDSEC(p) fat_getuint32(UBYTE_PTR(p,BS_HIDSEC))
# define MBR_GETTOTSEC32(p) fat_getuint32(UBYTE_PTR(p,BS_TOTSEC32))
# define MBR_GETFATSZ32(p) fat_getuint32(UBYTE_PTR(p,BS32_FATSZ32))
# define MBR_GETEXTFLAGS(p) fat_getuint16(UBYTE_PTR(p,BS32_EXTFLAGS))
# define MBR_GETFSVER(p) fat_getuint16(UBYTE_PTR(p,BS32_FSVER))
# define MBR_GETROOTCLUS(p) fat_getuint32(UBYTE_PTR(p,BS32_ROOTCLUS))
# define MBR_GETFSINFO(p) fat_getuint16(UBYTE_PTR(p,BS32_FSINFO))
# define MBR_GETBKBOOTSEC(p) fat_getuint16(UBYTE_PTR(p,BS32_BKBOOTSEC))
# define MBR_GETSIGNATURE(p) fat_getuint16(UBYTE_PTR(p,BS_SIGNATURE))
# define MBR_GETPARTSECTOR(s) fat_getuint32(s)
# define FSI_GETLEADSIG(p) fat_getuint32(UBYTE_PTR(p,FSI_LEADSIG))
# define FSI_GETSTRUCTSIG(p) fat_getuint32(UBYTE_PTR(p,FSI_STRUCTSIG))
# define FSI_GETFREECOUNT(p) fat_getuint32(UBYTE_PTR(p,FSI_FREECOUNT))
# define FSI_GETNXTFREE(p) fat_getuint32(UBYTE_PTR(p,FSI_NXTFREE))
# define FSI_GETTRAILSIG(p) fat_getuint32(UBYTE_PTR(p,FSI_TRAILSIG))
# define DIR_GETCRTIME(p) fat_getuint16(UBYTE_PTR(p,DIR_CRTIME))
# define DIR_GETCRDATE(p) fat_getuint16(UBYTE_PTR(p,DIR_CRDATE))
# define DIR_GETLASTACCDATE(p) fat_getuint16(UBYTE_PTR(p,DIR_LASTACCDTE))
# define DIR_GETFSTCLUSTHI(p) fat_getuint16(UBYTE_PTR(p,DIR_FSTCLUSTHI))
# define DIR_GETWRTTIME(p) fat_getuint16(UBYTE_PTR(p,DIR_WRTTIME))
# define DIR_GETWRTDATE(p) fat_getuint16(UBYTE_PTR(p,DIR_WRTDATE))
# define DIR_GETFSTCLUSTLO(p) fat_getuint16(UBYTE_PTR(p,DIR_FSTCLUSTLO))
# define DIR_GETFILESIZE(p) fat_getuint32(UBYTE_PTR(p,DIR_FILESIZE))
# define FAT_GETFAT16(p,i) fat_getuint16(UBYTE_PTR(p,i))
# define FAT_GETFAT32(p,i) fat_getuint32(UBYTE_PTR(p,i))
# define MBR_PUTRESVDSECCOUNT(p,v) fat_putuint16(UBYTE_PTR(p,BS_RESVDSECCOUNT,v))
# define MBR_PUTFATSZ16(p,v) fat_putuint16(UBYTE_PTR(p,BS_FATSZ16,v))
# define MBR_PUTSECPERTRK(p,v) fat_putuint16(UBYTE_PTR(p,BS_SECPERTRK,v))
# define MBR_PUTNUMHEADS(p,v) fat_putuint16(UBYTE_PTR(p,BS_NUMHEADS,v))
# define MBR_PUTHIDSEC(p,v) fat_putuint32(UBYTE_PTR(p,BS_HIDSEC,v))
# define MBR_PUTTOTSEC32(p,v) fat_putuint32(UBYTE_PTR(p,BS_TOTSEC32,v))
# define MBR_PUTFATSZ32(p,v) fat_putuint32(UBYTE_PTR(p,BS32_FATSZ32,v))
# define MBR_PUTEXTFLAGS(p,v) fat_putuint16(UBYTE_PTR(p,BS32_EXTFLAGS,v))
# define MBR_PUTFSVER(p,v) fat_putuint16(UBYTE_PTR(p,BS32_FSVER,v))
# define MBR_PUTROOTCLUS(p,v) fat_putuint32(UBYTE_PTR(p,BS32_ROOTCLUS,v))
# define MBR_PUTFSINFO(p,v) fat_putuint16(UBYTE_PTR(p,BS32_FSINFO,v))
# define MBR_PUTBKBOOTSEC(p,v) fat_putuint16(UBYTE_PTR(p,BS32_BKBOOTSEC,v))
# define MBR_PUTSIGNATURE(p,v) fat_getuint16(UBYTE_PTR(p,BS_SIGNATURE),v)
# define FSI_PUTLEADSIG(p,v) fat_putuint32(UBYTE_PTR(p,FSI_LEADSIG),v)
# define FSI_PUTSTRUCTSIG(p,v) fat_putuint32(UBYTE_PTR(p,FSI_STRUCTSIG),v)
# define FSI_PUTFREECOUNT(p,v) fat_putuint32(UBYTE_PTR(p,FSI_FREECOUNT),v)
# define FSI_PUTNXTFREE(p,v) fat_putuint32(UBYTE_PTR(p,FSI_NXTFREE),v)
# define FSI_PUTTRAILSIG(p,v) fat_putuint32(UBYTE_PTR(p,FSI_TRAILSIG),v)
# define DIR_PUTCRTIME(p,v) fat_putuint16(UBYTE_PTR(p,DIR_CRTIME),v)
# define DIR_PUTCRDATE(p,v) fat_putuint16(UBYTE_PTR(p,DIR_CRDATE),v)
# define DIR_PUTLASTACCDATE(p,v) fat_putuint16(UBYTE_PTR(p,DIR_LASTACCDTE),v)
# define DIR_PUTFSTCLUSTHI(p,v) fat_putuint16(UBYTE_PTR(p,DIR_FSTCLUSTHI),v)
# define DIR_PUTWRTTIME(p,v) fat_putuint16(UBYTE_PTR(p,DIR_WRTTIME),v)
# define DIR_PUTWRTDATE(p,v) fat_putuint16(UBYTE_PTR(p,DIR_WRTDATE),v)
# define DIR_PUTFSTCLUSTLO(p,v) fat_putuint16(UBYTE_PTR(p,DIR_FSTCLUSTLO),v)
# define DIR_PUTFILESIZE(p,v) fat_putuint32(UBYTE_PTR(p,DIR_FILESIZE),v)
# define FAT_PUTFAT16(p,i,v) fat_putuint16(UBYTE_PTR(p,i),v)
# define FAT_PUTFAT32(p,i,v) fat_putuint32(UBYTE_PTR(p,i),v)
#else
/* But nothing special has to be done for the little endian-case for access
* to aligned mulitbyte values.
*/
# define MBR_GETRESVDSECCOUNT(p) UINT16_VAL(p,BS_RESVDSECCOUNT)
# define MBR_GETFATSZ16(p) UINT16_VAL(p,BS_FATSZ16)
# define MBR_GETSECPERTRK(p) UINT16_VAL(p,BS_SECPERTRK)
# define MBR_GETNUMHEADS(p) UINT16_VAL(p,BS_NUMHEADS)
# define MBR_GETHIDSEC(p) UINT32_VAL(p,BS_HIDSEC)
# define MBR_GETTOTSEC32(p) UINT32_VAL(p,BS_TOTSEC32)
# define MBR_GETFATSZ32(p) UINT32_VAL(p,BS32_FATSZ32)
# define MBR_GETEXTFLAGS(p) UINT16_VAL(p,BS32_EXTFLAGS)
# define MBR_GETFSVER(p) UINT16_VAL(p,BS32_FSVER)
# define MBR_GETROOTCLUS(p) UINT32_VAL(p,BS32_ROOTCLUS)
# define MBR_GETFSINFO(p) UINT16_VAL(p,BS32_FSINFO)
# define MBR_GETBKBOOTSEC(p) UINT16_VAL(p,BS32_BKBOOTSEC)
# define MBR_GETSIGNATURE(p) UINT16_VAL(p,BS_SIGNATURE)
# define MBR_GETPARTSECTOR(s) (*((uint32*)(s)))
# define FSI_GETLEADSIG(p) UINT32_VAL(p,FSI_LEADSIG)
# define FSI_GETSTRUCTSIG(p) UINT32_VAL(p,FSI_STRUCTSIG)
# define FSI_GETFREECOUNT(p) UINT32_VAL(p,FSI_FREECOUNT)
# define FSI_GETNXTFREE(p) UINT32_VAL(p,FSI_NXTFREE)
# define FSI_GETTRAILSIG(p) UINT32_VAL(p,FSI_TRAILSIG)
# define DIR_GETCRTIME(p) UINT16_VAL(p,DIR_CRTIME)
# define DIR_GETCRDATE(p) UINT16_VAL(p,DIR_CRDATE)
# define DIR_GETLASTACCDATE(p) UINT16_VAL(p,DIR_LASTACCDTE)
# define DIR_GETFSTCLUSTHI(p) UINT16_VAL(p,DIR_FSTCLUSTHI)
# define DIR_GETWRTTIME(p) UINT16_VAL(p,DIR_WRTTIME)
# define DIR_GETWRTDATE(p) UINT16_VAL(p,DIR_WRTDATE)
# define DIR_GETFSTCLUSTLO(p) UINT16_VAL(p,DIR_FSTCLUSTLO)
# define DIR_GETFILESIZE(p) UINT32_VAL(p,DIR_FILESIZE)
# define FAT_GETFAT16(p,i) UINT16_VAL(p,i)
# define FAT_GETFAT32(p,i) UINT32_VAL(p,i)
# define MBR_PUTRESVDSECCOUNT(p,v) UINT16_PUT(p,BS_RESVDSECCOUNT,v)
# define MBR_PUTFATSZ16(p,v) UINT16_PUT(p,BS_FATSZ16,v)
# define MBR_PUTSECPERTRK(p,v) UINT16_PUT(p,BS_SECPERTRK,v)
# define MBR_PUTNUMHEADS(p,v) UINT16_PUT(p,BS_NUMHEADS,v)
# define MBR_PUTHIDSEC(p,v) UINT32_PUT(p,BS_HIDSEC,v)
# define MBR_PUTTOTSEC32(p,v) UINT32_PUT(p,BS_TOTSEC32,v)
# define MBR_PUTFATSZ32(p,v) UINT32_PUT(p,BS32_FATSZ32,v)
# define MBR_PUTEXTFLAGS(p,v) UINT16_PUT(p,BS32_EXTFLAGS,v)
# define MBR_PUTFSVER(p,v) UINT16_PUT(p,BS32_FSVER,v)
# define MBR_PUTROOTCLUS(p,v) UINT32_PUT(p,BS32_ROOTCLUS,v)
# define MBR_PUTFSINFO(p,v) UINT16_PUT(p,BS32_FSINFO,v)
# define MBR_PUTBKBOOTSEC(p,v) UINT16_PUT(p,BS32_BKBOOTSEC,v)
# define MBR_PUTSIGNATURE(p,v) UINT16_PUT(p,BS_SIGNATURE,v)
# define FSI_PUTLEADSIG(p,v) UINT32_PUT(p,FSI_LEADSIG,v)
# define FSI_PUTSTRUCTSIG(p,v) UINT32_PUT(p,FSI_STRUCTSIG,v)
# define FSI_PUTFREECOUNT(p,v) UINT32_PUT(p,FSI_FREECOUNT,v)
# define FSI_PUTNXTFREE(p,v) UINT32_PUT(p,FSI_NXTFREE,v)
# define FSI_PUTTRAILSIG(p,v) UINT32_PUT(p,FSI_TRAILSIG,v)
# define DIR_PUTCRTIME(p,v) UINT16_PUT(p,DIR_CRTIME,v)
# define DIR_PUTCRDATE(p,v) UINT16_PUT(p,DIR_CRDATE,v)
# define DIR_PUTLASTACCDATE(p,v) UINT16_PUT(p,DIR_LASTACCDTE,v)
# define DIR_PUTFSTCLUSTHI(p,v) UINT16_PUT(p,DIR_FSTCLUSTHI,v)
# define DIR_PUTWRTTIME(p,v) UINT16_PUT(p,DIR_WRTTIME,v)
# define DIR_PUTWRTDATE(p,v) UINT16_PUT(p,DIR_WRTDATE,v)
# define DIR_PUTFSTCLUSTLO(p,v) UINT16_PUT(p,DIR_FSTCLUSTLO,v)
# define DIR_PUTFILESIZE(p,v) UINT32_PUT(p,DIR_FILESIZE,v)
# define FAT_PUTFAT16(p,i,v) UINT16_PUT(p,i,v)
# define FAT_PUTFAT32(p,i,v) UINT32_PUT(p,i,v)
#endif
/****************************************************************************
* Public Types
****************************************************************************/
/* 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 */
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 */
size_t fs_currentsector; /* The sector number buffered in fs_buffer */
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 */
boolean fs_mounted; /* TRUE: The file system is ready */
boolean fs_dirty; /* TRUE: fs_buffer is dirty */
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; /* Retained in a singly linked list */
boolean ff_open; /* TRUE: The file is (still) open */
boolean ff_bflags; /* The file buffer flags */
ubyte ff_oflags; /* Flags provided when file was opened */
ubyte ff_sectorsincluster; /* Sectors remaining in cluster */
uint16 ff_dirindex; /* Index into ff_dirsector to directory entry */
uint32 ff_currentcluster; /* Current cluster being accessed */
size_t ff_dirsector; /* Sector containing the directory entry */
size_t ff_position; /* File position for read/write/seek in bytes */
size_t ff_size; /* Size of the file in bytes */
size_t ff_startcluster; /* Start cluster of file on media */
size_t ff_currentsector; /* Current sector in the file buffer */
ubyte *ff_buffer; /* File buffer (for partial sector accesses) */
};
/* This structure is used internally for describing directory entries */
struct fat_dirinfo_s
{
struct fat_mountpt_s *fs; /* Pointer to the parent mountpoint */
ubyte fd_name[8+3]; /* Filename -- directory format*/
#ifdef CONFIG_FAT_LCNAMES
ubyte fd_ntflags; /* NTRes lower case flags */
#endif
uint16 fd_index; /* Current index */
size_t fd_startcluster; /* Start cluster number */
size_t fd_currcluster; /* Current cluster number */
size_t fd_currsector; /* Current sector */
ubyte *fd_entry; /* A pointer to the raw 32-byte entry */
};
/****************************************************************************
* Global Variables
****************************************************************************/
/****************************************************************************
* Pulblic Function Prototypes
****************************************************************************/
#undef EXTERN
#if defined(__cplusplus)
#define EXTERN extern "C"
extern "C" {
#else
#define EXTERN extern
#endif
/* Utitilies to handle unaligned or byte swapped accesses */
EXTERN uint16 fat_getuint16(ubyte *ptr);
EXTERN uint32 fat_getuint32(ubyte *ptr);
EXTERN void fat_putuint16(ubyte *ptr, uint16 value16);
EXTERN void fat_putuint32(ubyte *ptr, uint32 value32);
/* Manage the per-mount semaphore that protects access to shared resources */
EXTERN void fat_semtake(struct fat_mountpt_s *fs);
EXTERN void fat_semgive(struct fat_mountpt_s *fs);
/* Handle hardware interactions for mounting */
EXTERN int fat_mount(struct fat_mountpt_s *fs, boolean writeable);
EXTERN int fat_checkmount(struct fat_mountpt_s *fs);
/* low-level hardware access */
EXTERN int fat_hwread(struct fat_mountpt_s *fs, ubyte *buffer, size_t sector,
unsigned int nsectors);
EXTERN int fat_hwwrite(struct fat_mountpt_s *fs, ubyte *buffer, size_t sector,
unsigned int nsectors);
/* Cluster access helpers */
EXTERN ssize_t fat_cluster2sector(struct fat_mountpt_s *fs, uint32 cluster );
EXTERN ssize_t fat_getcluster(struct fat_mountpt_s *fs, unsigned int clusterno);
EXTERN int fat_putcluster(struct fat_mountpt_s *fs, unsigned int clusterno, size_t startsector);
/* Help for traverseing directory trees */
EXTERN int fat_nextdirentry(struct fat_dirinfo_s *dirinfo);
EXTERN int fat_finddirentry(struct fat_dirinfo_s *dirinfo, const char *path);
/* File creation helpers */
EXTERN int fat_dirtruncate(struct fat_mountpt_s *fs, struct fat_dirinfo_s *dirinfo);
EXTERN int fat_dircreate(struct fat_mountpt_s *fs, struct fat_dirinfo_s *dirinfo);
/* File buffer cache (for partial sector accesses) */
EXTERN int fat_ffcacheflush(struct fat_mountpt_s *fs, struct fat_file_s *ff);
EXTERN int fat_ffcacheread(struct fat_mountpt_s *fs, struct fat_file_s *ff, size_t sector);
EXTERN int fat_ffcacheinvalidate(struct fat_mountpt_s *fs, struct fat_file_s *ff);
#undef EXTERN
#if defined(__cplusplus)
}
#endif
#endif /* __FS_FAT32_H */
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