/**************************************************************************** * fs_fat.h * * Copyright (C) 2007 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * 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 #include #include /**************************************************************************** * 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 */