//////////////////////////////////////////////////////////////////////////// // File : fat32.h // Date : 01/09/2013 // Author : Marco Jankovic / Alain Greiner // Copyright (c) UPMC-LIP6 //////////////////////////////////////////////////////////////////////////// #ifndef _FAT32_H #define _FAT32_H #include "giet_config.h" /*************** Partition Boot Sector Format ******************************************/ // offset | length #define BS_JMPBOOT 0 , 3 #define BS_OEMNAME 3 , 8 #define BPB_BYTSPERSEC 11 , 2 #define BPB_SECPERCLUS 13 , 1 #define BPB_RSVDSECCNT 14 , 2 #define BPB_NUMFATS 16 , 1 #define BPB_ROOTENTCNT 17 , 2 #define BPB_TOTSEC16 19 , 2 #define BPB_MEDIA 21 , 1 #define BPB_FATSZ16 22 , 2 #define BPB_SECPERTRK 24 , 2 #define BPB_NUMHEADS 26 , 2 #define BPB_HIDDSEC 28 , 4 #define BPB_TOTSEC32 32 , 4 #define BPB_PARTITION_TABLE 446 , 64 // FAT 32 #define BPB_FAT32_FATSZ32 36 , 4 #define BPB_FAT32_EXTFLAGS 40 , 2 #define BPB_FAT32_FSVER 42 , 2 #define BPB_FAT32_ROOTCLUS 44 , 4 #define BPB_FAT32_FSINFO 48 , 2 #define BPB_FAT32_BKBOOTSEC 50 , 2 #define BS_FAT32_DRVNUM 64 , 1 #define BS_FAT32_BOOTSIG 66 , 1 #define BS_FAT32_VOLID 67 , 4 #define BS_FAT32_VOLLAB 71 , 11 #define BS_FAT32_FILSYSTYPE 82 , 8 // Partitions #define FIRST_PARTITION_ACTIVE 446 , 8 #define FIRST_PARTITION_BEGIN_LBA 454 , 4 #define FIRST_PARTITION_SIZE 458 , 4 #define SECOND_PARTITION_ACTIVE 462 , 8 #define SECOND_PARTITION_BEGIN_LBA 470 , 4 #define SECOND_PARTITION_SIZE 474 , 4 #define THIRD_PARTITION_ACTIVE 478 , 8 #define THIRD_PARTITION_BEGIN_LBA 486 , 4 #define THIRD_PARTITION_SIZE 490 , 4 #define FOURTH_PARTITION_ACTIVE 494 , 8 #define FOURTH_PARTITION_BEGIN_LBA 502 , 4 #define FOURTH_PARTITION_SIZE 506 , 4 /***************************************************************************************/ #define MBR_SIGNATURE_POSITION 510 , 2 #define MBR_SIGNATURE_VALUE 0xAA55 /************** FAT_FS_INFO SECTOR ****************************************************/ #define FS_SIGNATURE_VALUE_1 0x52526141 #define FS_SIGNATURE_VALUE_2 0x72724161 #define FS_SIGNATURE_VALUE_3 0x000055AA #define FS_SIGNATURE_POSITION_1 0 , 4 #define FS_SIGNATURE_POSITION_2 484 , 4 #define FS_SIGNATURE_POSITION_3 508 , 4 #define FS_FREE_CLUSTER 488 , 4 #define FS_FREE_CLUSTER_HINT 492 , 4 /***************************************************************************************/ #define DIR_ENTRY_SIZE 32 /******* Directory Entry Structure (32 bytes) ******************************************/ // offset | length #define DIR_NAME 0 , 11 // dir_entry name #define DIR_ATTR 11 , 1 // attributes #define DIR_NTRES 12 , 1 // reserved for the OS #define DIR_CRT_TIMES_TENTH 13 , 1 #define DIR_FST_CLUS_HI 20 , 2 // cluster index 16 MSB bits #define DIR_WRT_TIME 22 , 2 // time of last write #define DIR_WRT_DATE 24 , 2 // date of last write #define DIR_FST_CLUS_LO 26 , 2 // cluster index 16 LSB bit #define DIR_FILE_SIZE 28 , 4 // file size (up to 4 giga bytes) /***************************************************************************************/ /******* LFN Directory Entry Structure (32 bytes) *************************************/ // offset | length #define LDIR_ORD 0 , 1 // Sequence number (from 0x01 to 0x0f) #define LDIR_NAME_1 1 , 10 // name broken into 3 parts #define LDIR_ATTR 11 , 1 // attributes (must be 0x0F) #define LDIR_TYPE 12 , 1 // directory type (must be 0x00) #define LDIR_CHKSUM 13 , 1 // checksum of name in short dir #define LDIR_NAME_2 14 , 12 #define LDIR_RSVD 26 , 2 // artifact of previous fat (must be 0) #define LDIR_NAME_3 28 , 4 /***************************************************************************************/ /*********************** DIR_ATTR values (attributes) ********************************/ #define ATTR_READ_ONLY 0x01 #define ATTR_HIDDEN 0x02 #define ATTR_SYSTEM 0x04 #define ATTR_VOLUME_ID 0x08 #define ATTR_DIRECTORY 0x10 #define ATTR_ARCHIVE 0x20 #define ATTR_LONG_NAME_MASK 0x0f // READ_ONLY|HIDDEN|SYSTEM|VOLUME_ID /***************************************************************************************/ /********************* DIR_ORD special values ******************************************/ #define FREE_ENTRY 0xE5 // this entry is free in the directory #define NO_MORE_ENTRY 0x00 // no more entry in the directory /***************************************************************************************/ /******************** CLuster Index Special Values *************************************/ #define FREE_CLUSTER 0x00000000 #define RESERVED_CLUSTER 0x00000001 #define BAD_CLUSTER 0x0FFFFFF7 #define END_OF_CHAIN_CLUSTER 0x0ffffff8 /***************************************************************************************/ #define FAT_INITIALISED 0xBABEF00D /************ This struct defines a file descriptor ************************************/ typedef struct file_descriptor_s { unsigned int used; // descriptor contains an open file unsigned int first_cluster; // first cluster index in partition unsigned int file_size; // number of bytes unsigned int lba_dir_entry; // lba of dir_entry for an open file char name[244]; // pathname } file_desc_t; /***************************************************************************************/ /************ This struct describes a FAT32 partition **********************************/ typedef struct fat32_fs_s { char fat_cache[512]; // FAT cache: 1 sector = 128 cluster indexes file_desc_t fd[GIET_OPEN_FILES_MAX]; // file descriptors array unsigned int initialised; // contains 0xBABEF00D when FAT initialised unsigned int sector_size; // number of bytes (power of 2) unsigned int sectors_per_cluster; // power of 2 (must be greater than 4) unsigned int cluster_size; // sector_size * sector_per_cluster (bytes) unsigned int fat_sectors; // number of sectors occupied by one FAT copy unsigned int partition_sectors; // total number of sectors (RESVD+FAT+DATA) unsigned int partition_lba; // lba of first partiton sector unsigned int data_lba; // lba of first data sector unsigned int cache_lba; // lba of sector loaded in fat_cache unsigned int last_cluster_allocated; // Last known cluster allocated unsigned int number_free_cluster; // number of free clusters unsigned int fs_info_lba; // lba of fs_info unsigned int lock; // lock protecting exclusive access } fat32_fs_t; /***************************************************************************************/ /*********************** Export Functions *********************************************/ extern void _fat_print(); // functions used for low level access to fat // (move sectors between block device and system buffers) extern int _fat_init( unsigned int mode ); // mode for IOC driver extern int _fat_open( unsigned int mode, // mode for IOC driver char* pathname, // file pathname from root unsigned int create ); // create new file if non zero extern int _fat_read( unsigned int mode, // mode for IOC driver unsigned int fd_id, // file descriptor index void* buffer, // destination buffer unsigned int count, // number of sectors to read unsigned int offset ); // offset sector in file extern int _fat_write( unsigned int mode, // mode for IOC driver unsigned int fd_id, // file descriptor index void* buffer, // source buffer unsigned int count, // number of sectors to write unsigned int offset ); // offset sector in file extern int _fat_fstat( unsigned int fd_id ); // file descriptor index extern int _fat_close( unsigned int fd_id ); // file descriptor index // functions used by user system calls // (should move bytes between system buffers and user buffers) extern int _fat_user_open( char* pathname, // file pathname from root unsigned int flags ); // unused extern int _fat_user_read( unsigned int fd_id, // file descriptor index void* buffer, // destination buffer unsigned int count, // number of sectors to read unsigned int offset ); // number of sectors to skip in file extern int _fat_user_write( unsigned int fd_id, // file descriptor index void* buffer, // source buffer unsigned int count, // number of sectors to write unsigned int offset ); // number of sectors to skip in file extern int _fat_user_lseek( unsigned int fd_id, unsigned int offset, unsigned int whence ); /***************************************************************************************/ #endif // Local Variables: // tab-width: 4 // c-basic-offset: 4 // c-file-offsets:((innamespace . 0)(inline-open . 0)) // indent-tabs-mode: nil // End: // vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4