/** * @file * * @brief Constants/Data Structures/Prototypes on a Volume with FAT Filesystem * * @ingroup libfs_dosfs * * Constants/Data Structures/Prototypes for Low-Level * Operations on a Volume with FAT Filesystem */ /* * * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia * Author: Eugeny S. Mints * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.rtems.org/license/LICENSE. */ #ifndef __DOSFS_FAT_H__ #define __DOSFS_FAT_H__ #include #include #include #include #include #include /** * @defgroup libfs_dosfs FAT FileSystem * * @ingroup libfs */ /**@{*/ #ifdef __cplusplus extern "C" { #endif #ifndef RC_OK #define RC_OK 0 #endif /* * Remember that all FAT file system on disk data structure is * "little endian"! * (derived from linux) */ /* * Conversion from and to little-endian byte order. (no-op on i386/i486) * * Naming: Ca_b_c, where a: F = from, T = to, b: LE = little-endian, * BE = big-endian, c: W = word (16 bits), L = longword (32 bits) */ #if (CPU_BIG_ENDIAN == TRUE) # define CF_LE_W(v) CPU_swap_u16((uint16_t)(v)) # define CF_LE_L(v) CPU_swap_u32((uint32_t)(v)) # define CT_LE_W(v) CPU_swap_u16((uint16_t)(v)) # define CT_LE_L(v) CPU_swap_u32((uint32_t)(v)) #else # define CF_LE_W(v) (v) # define CF_LE_L(v) (v) # define CT_LE_W(v) (v) # define CT_LE_L(v) (v) #endif #define FAT_HASH_SIZE 2 #define FAT_HASH_MODULE FAT_HASH_SIZE #define FAT_SECTOR512_SIZE 512 /* sector size (bytes) */ #define FAT_SECTOR512_BITS 9 /* log2(SECTOR_SIZE) */ /* maximum + 1 number of clusters for FAT12 */ #define FAT_FAT12_MAX_CLN 4085 /* maximum + 1 number of clusters for FAT16 */ #define FAT_FAT16_MAX_CLN 65525 #define FAT_FAT12 0x01 #define FAT_FAT16 0x02 #define FAT_FAT32 0x04 #define FAT_UNDEFINED_VALUE (uint32_t)0xFFFFFFFF #define FAT_FAT12_EOC 0x0FF8 #define FAT_FAT16_EOC 0xFFF8 #define FAT_FAT32_EOC (uint32_t)0x0FFFFFF8 #define FAT_FAT12_FREE 0x0000 #define FAT_FAT16_FREE 0x0000 #define FAT_FAT32_FREE 0x00000000 #define FAT_GENFAT_EOC (uint32_t)0xFFFFFFFF #define FAT_GENFAT_FREE (uint32_t)0x00000000 #define FAT_FAT12_SHIFT 0x04 #define FAT_FAT12_MASK 0x00000FFF #define FAT_FAT16_MASK 0x0000FFFF #define FAT_FAT32_MASK (uint32_t)0x0FFFFFFF #define FAT_MAX_BPB_SIZE 90 #define FAT_TOTAL_MBR_SIZE 512 /* size of useful information in FSInfo sector */ #define FAT_USEFUL_INFO_SIZE 12 #define FAT_GET_ADDR(x, ofs) ((uint8_t *)(x) + (ofs)) #define FAT_GET_VAL8(x, ofs) (uint8_t)(*((uint8_t *)(x) + (ofs))) #define FAT_GET_VAL16(x, ofs) \ (uint16_t)( (*((uint8_t *)(x) + (ofs))) | \ ((*((uint8_t *)(x) + (ofs) + 1)) << 8) ) #define FAT_GET_VAL32(x, ofs) \ (uint32_t)( (uint32_t)(*((uint8_t *)(x) + (ofs))) | \ ((uint32_t)(*((uint8_t *)(x) + (ofs) + 1)) << 8) | \ ((uint32_t)(*((uint8_t *)(x) + (ofs) + 2)) << 16) | \ ((uint32_t)(*((uint8_t *)(x) + (ofs) + 3)) << 24) ) #define FAT_SET_VAL8(x, ofs,val) \ (*((uint8_t *)(x)+(ofs))=(uint8_t)(val)) #define FAT_SET_VAL16(x, ofs,val) do { \ FAT_SET_VAL8((x),(ofs),(val)); \ FAT_SET_VAL8((x),(ofs)+1,(val)>>8);\ } while (0) #define FAT_SET_VAL32(x, ofs,val) do { \ uint32_t val1 = val; \ FAT_SET_VAL16((x),(ofs),(val1)&0xffff);\ FAT_SET_VAL16((x),(ofs)+2,(val1)>>16);\ } while (0) /* macros to access boot sector fields */ #define FAT_GET_BR_JMPBOOT(x) FAT_GET_VAL8( x, 0) #define FAT_SET_BR_JMPBOOT(x,val) FAT_SET_VAL8( x, 0,val) #define FAT_GET_ADDR_BR_OEMNAME(x) FAT_GET_ADDR( x, 3) #define FAT_BR_OEMNAME_SIZE (8) #define FAT_GET_BR_BYTES_PER_SECTOR(x) FAT_GET_VAL16(x, 11) #define FAT_SET_BR_BYTES_PER_SECTOR(x,val) FAT_SET_VAL16(x, 11,val) #define FAT_GET_BR_SECTORS_PER_CLUSTER(x) FAT_GET_VAL8( x, 13) #define FAT_SET_BR_SECTORS_PER_CLUSTER(x,val)FAT_SET_VAL8( x, 13,val) #define FAT_GET_BR_RESERVED_SECTORS_NUM(x) FAT_GET_VAL16(x, 14) #define FAT_SET_BR_RESERVED_SECTORS_NUM(x,val) FAT_SET_VAL16(x, 14,val) #define FAT_GET_BR_FAT_NUM(x) FAT_GET_VAL8( x, 16) #define FAT_SET_BR_FAT_NUM(x,val) FAT_SET_VAL8( x, 16,val) #define FAT_GET_BR_FILES_PER_ROOT_DIR(x) FAT_GET_VAL16(x, 17) #define FAT_SET_BR_FILES_PER_ROOT_DIR(x,val) FAT_SET_VAL16(x, 17,val) #define FAT_GET_BR_TOTAL_SECTORS_NUM16(x) FAT_GET_VAL16(x, 19) #define FAT_SET_BR_TOTAL_SECTORS_NUM16(x,val)FAT_SET_VAL16(x, 19,val) #define FAT_GET_BR_MEDIA(x) FAT_GET_VAL8( x, 21) #define FAT_SET_BR_MEDIA(x,val) FAT_SET_VAL8( x, 21,val) #define FAT_GET_BR_SECTORS_PER_FAT(x) FAT_GET_VAL16(x, 22) #define FAT_SET_BR_SECTORS_PER_FAT(x,val) FAT_SET_VAL16(x, 22,val) #define FAT_GET_BR_SECTORS_PER_TRACK(x) FAT_GET_VAL16(x, 24) #define FAT_SET_BR_SECTORS_PER_TRACK(x,val) FAT_SET_VAL16(x, 24,val) #define FAT_GET_BR_NUMBER_OF_HEADS(x) FAT_GET_VAL16(x, 26) #define FAT_SET_BR_NUMBER_OF_HEADS(x,val) FAT_SET_VAL16(x, 26,val) #define FAT_GET_BR_HIDDEN_SECTORS(x) FAT_GET_VAL32(x, 28) #define FAT_SET_BR_HIDDEN_SECTORS(x,val) FAT_SET_VAL32(x, 28,val) #define FAT_GET_BR_TOTAL_SECTORS_NUM32(x) FAT_GET_VAL32(x, 32) #define FAT_SET_BR_TOTAL_SECTORS_NUM32(x,val) FAT_SET_VAL32(x, 32,val) /* --- start of FAT12/16 specific fields */ #define FAT_GET_BR_DRVNUM(x) FAT_GET_VAL8( x, 36) #define FAT_SET_BR_DRVNUM(x,val) FAT_SET_VAL8( x, 36,val) #define FAT_GET_BR_RSVD1(x) FAT_GET_VAL8( x, 37) #define FAT_SET_BR_RSVD1(x,val) FAT_SET_VAL8( x, 37,val) #define FAT_GET_BR_BOOTSIG(x) FAT_GET_VAL8( x, 38) #define FAT_SET_BR_BOOTSIG(x,val) FAT_SET_VAL8( x, 38,val) #define FAT_BR_BOOTSIG_VAL (0x29) #define FAT_GET_BR_VOLID(x) FAT_GET_VAL32(x, 39) #define FAT_SET_BR_VOLID(x,val) FAT_SET_VAL32(x, 39,val) #define FAT_GET_ADDR_BR_VOLLAB(x) FAT_GET_ADDR (x, 43) #define FAT_BR_VOLLAB_SIZE (11) #define FAT_GET_ADDR_BR_FILSYSTYPE(x) FAT_GET_ADDR (x, 54) #define FAT_BR_FILSYSTYPE_SIZE (8) /* --- end of FAT12/16 specific fields */ /* --- start of FAT32 specific fields */ #define FAT_GET_BR_SECTORS_PER_FAT32(x) FAT_GET_VAL32(x, 36) #define FAT_SET_BR_SECTORS_PER_FAT32(x,val) FAT_SET_VAL32(x, 36,val) #define FAT_GET_BR_EXT_FLAGS(x) FAT_GET_VAL16(x, 40) #define FAT_SET_BR_EXT_FLAGS(x,val) FAT_SET_VAL16(x, 40,val) #define FAT_GET_BR_FSVER(x) FAT_GET_VAL16(x, 42) #define FAT_SET_BR_FSVER(x,val) FAT_SET_VAL16(x, 42,val) #define FAT_GET_BR_FAT32_ROOT_CLUSTER(x) FAT_GET_VAL32(x, 44) #define FAT_SET_BR_FAT32_ROOT_CLUSTER(x,val) FAT_SET_VAL32(x, 44,val) #define FAT_GET_BR_FAT32_FS_INFO_SECTOR(x) FAT_GET_VAL16(x, 48) #define FAT_SET_BR_FAT32_FS_INFO_SECTOR(x,val) FAT_SET_VAL16(x, 48,val) #define FAT_GET_BR_FAT32_BK_BOOT_SECTOR(x) FAT_GET_VAL16(x, 50) #define FAT_SET_BR_FAT32_BK_BOOT_SECTOR(x,val) FAT_SET_VAL16(x, 50,val) #define FAT_GET_ADDR_BR_FAT32_RESERVED(x) FAT_GET_ADDR (x, 52) #define FAT_BR_FAT32_RESERVED_SIZE (12) #define FAT_GET_BR_FAT32_DRVNUM(x) FAT_GET_VAL8( x, 64) #define FAT_SET_BR_FAT32_DRVNUM(x,val) FAT_SET_VAL8( x, 64,val) #define FAT_GET_BR_FAT32_RSVD1(x) FAT_GET_VAL8( x, 65) #define FAT_SET_BR_FAT32_RSVD1(x,val) FAT_SET_VAL8( x, 65,val) #define FAT_GET_BR_FAT32_BOOTSIG(x) FAT_GET_VAL8( x, 66) #define FAT_SET_BR_FAT32_BOOTSIG(x,val) FAT_SET_VAL8( x, 66,val) #define FAT_BR_FAT32_BOOTSIG_VAL (0x29) #define FAT_GET_BR_FAT32_VOLID(x) FAT_GET_VAL32(x, 67) #define FAT_SET_BR_FAT32_VOLID(x,val) FAT_SET_VAL32(x, 67,val) #define FAT_GET_ADDR_BR_FAT32_VOLLAB(x) FAT_GET_ADDR (x, 71) #define FAT_BR_FAT32_VOLLAB_SIZE (11) #define FAT_GET_ADDR_BR_FAT32_FILSYSTYPE(x) FAT_GET_ADDR (x, 82) #define FAT_BR_FAT32_FILSYSTYPE_SIZE (8) /* --- end of FAT32 specific fields */ #define FAT_GET_BR_SIGNATURE(x) FAT_GET_VAL16(x,510) #define FAT_SET_BR_SIGNATURE(x,val) FAT_SET_VAL16(x,510,val) #define FAT_BR_SIGNATURE_VAL (0xAA55) /* * FAT32 FSINFO description */ #define FAT_GET_FSINFO_LEAD_SIGNATURE(x) FAT_GET_VAL32(x, 0) #define FAT_SET_FSINFO_LEAD_SIGNATURE(x,val) FAT_SET_VAL32(x, 0,val) #define FAT_FSINFO_LEAD_SIGNATURE_VALUE (0x41615252) #define FAT_GET_FSINFO_STRUC_SIGNATURE(x) FAT_GET_VAL32(x,484) #define FAT_SET_FSINFO_STRUC_SIGNATURE(x,val) FAT_SET_VAL32(x,484,val) #define FAT_FSINFO_STRUC_SIGNATURE_VALUE (0x61417272) #define FAT_GET_FSINFO_TRAIL_SIGNATURE(x) FAT_GET_VAL32(x,508) #define FAT_SET_FSINFO_TRAIL_SIGNATURE(x,val) FAT_SET_VAL32(x,508,val) #define FAT_FSINFO_TRAIL_SIGNATURE_VALUE (0xAA550000) /* * I read FSInfo sector from offset 484 to access the information, so offsets * of these fields a relative */ #define FAT_GET_FSINFO_FREE_CLUSTER_COUNT(x) FAT_GET_VAL32(x, 4) #define FAT_SET_FSINFO_FREE_CLUSTER_COUNT(x,val) FAT_SET_VAL32(x, 4,val) #define FAT_GET_FSINFO_NEXT_FREE_CLUSTER(x) FAT_GET_VAL32(x, 8) #define FAT_SET_FSINFO_NEXT_FREE_CLUSTER(x,val) FAT_SET_VAL32(x, 8,val) #define FAT_FSI_INFO 484 #define FAT_FSINFO_STRUCT_OFFSET 488 #define FAT_FSINFO_FREE_CLUSTER_COUNT_OFFSET (FAT_FSINFO_STRUCT_OFFSET+0) #define FAT_FSINFO_NEXT_FREE_CLUSTER_OFFSET (FAT_FSINFO_STRUCT_OFFSET+4) #define FAT_RSRVD_CLN 0x02 #define FAT_FSI_LEADSIG_SIZE 0x04 #define FAT_TOTAL_FSINFO_SIZE 512 #define MS_BYTES_PER_CLUSTER_LIMIT 0x8000 /* 32K */ #define MS_BYTES_PER_CLUSTER_LIMIT_FAT12 0x1000 /* 4K */ #define FAT_BR_EXT_FLAGS_MIRROR 0x0080 #define FAT_BR_EXT_FLAGS_FAT_NUM 0x000F #define FAT_BR_MEDIA_FIXED 0xf8 #define FAT_DIRENTRY_SIZE 32 #define FAT_DIRENTRIES_PER_SEC512 16 /* * Volume descriptor * Description of the volume the FAT filesystem is located on - generally * the fields of the structure correspond to Boot Sector and BPB Structure * fields */ typedef struct fat_vol_s { uint16_t bps; /* bytes per sector */ uint8_t sec_log2; /* log2 of bps */ uint8_t sec_mul; /* log2 of 512bts sectors number per sector */ uint8_t spc; /* sectors per cluster */ uint8_t spc_log2; /* log2 of spc */ uint16_t bpc; /* bytes per cluster */ uint8_t bpc_log2; /* log2 of bytes per cluster */ uint8_t sectors_per_block; /* sectors per bdbuf block */ uint16_t bytes_per_block; /* number of bytes for the bduf block device handling */ uint8_t bytes_per_block_log2; /* log2 of bytes_per_block */ uint8_t fats; /* number of FATs */ uint8_t type; /* FAT type */ uint32_t mask; uint32_t eoc_val; uint16_t fat_loc; /* FAT start */ uint32_t fat_length; /* sectors per FAT */ uint32_t rdir_loc; /* root directory start */ uint16_t rdir_entrs; /* files per root directory */ uint32_t rdir_secs; /* sectors per root directory */ uint32_t rdir_size; /* root directory size in bytes */ uint32_t tot_secs; /* total count of sectors */ uint32_t data_fsec; /* first data sector */ uint32_t data_cls; /* count of data clusters */ uint32_t rdir_cl; /* first cluster of the root directory */ uint16_t info_sec; /* FSInfo Sector Structure location */ uint32_t free_cls; /* last known free clusters count */ uint32_t free_cls_in_fs_info; /* last known free clusters count in FS info sector */ uint32_t next_cl; /* next free cluster number */ uint32_t next_cl_in_fs_info; /* next free cluster number in FS info sector */ uint8_t mirror; /* mirroring enabla/disable */ uint32_t afat_loc; /* active FAT location */ uint8_t afat; /* the number of active FAT */ int fd; /* the disk device file descriptor */ rtems_disk_device *dd; /* disk device (see libblock) */ void *private_data; /* reserved */ } fat_vol_t; typedef struct fat_cache_s { uint32_t blk_num; bool modified; uint8_t state; rtems_bdbuf_buffer *buf; } fat_cache_t; /* * This structure identifies the instance of the filesystem on the FAT * ("fat-file") level. */ typedef struct fat_fs_info_s { fat_vol_t vol; /* volume descriptor */ rtems_chain_control *vhash; /* "vhash" of fat-file descriptors */ rtems_chain_control *rhash; /* "rhash" of fat-file descriptors */ char *uino; /* array of unique ino numbers */ uint32_t index; uint32_t uino_pool_size; /* size */ uint32_t uino_base; fat_cache_t c; /* cache */ uint8_t *sec_buf; /* just placeholder for anything */ } fat_fs_info_t; /* * FAT position is a the cluster and the offset into the * cluster. */ typedef struct fat_pos_s { uint32_t cln; uint32_t ofs; } fat_pos_t; /* * If the name we looking for is file we store not only first data cluster * number, but and cluster number and offset for directory entry for this * name. We also add the LFN start offset so we can delete it the whole * file name. We can then use this to delete the file. */ typedef struct fat_dir_pos_s { fat_pos_t sname; fat_pos_t lname; } fat_dir_pos_t; /* * Set the long name entries to this value for a short file name. */ #define FAT_FILE_SHORT_NAME (0xffffffff) #define FAT_FAT_OFFSET(fat_type, cln) \ ((fat_type) & FAT_FAT12 ? ((cln) + ((cln) >> 1)) : \ (fat_type) & FAT_FAT16 ? ((cln) << 1) : \ ((cln) << 2)) #define FAT_CLUSTER_IS_ODD(n) ((n) & 0x0001) #define FAT12_SHIFT 0x4 /* half of a byte */ /* initial size of array of unique ino */ #define FAT_UINO_POOL_INIT_SIZE 0x100 /* cache support */ #define FAT_CACHE_EMPTY 0x0 #define FAT_CACHE_ACTUAL 0x1 #define FAT_OP_TYPE_READ 0x1 #define FAT_OP_TYPE_GET 0x2 static inline void fat_dir_pos_init( fat_dir_pos_t *dir_pos ) { dir_pos->sname.cln = 0; dir_pos->sname.ofs = 0; dir_pos->lname.cln = FAT_FILE_SHORT_NAME; dir_pos->lname.ofs = FAT_FILE_SHORT_NAME; } static inline uint32_t fat_cluster_num_to_sector_num( const fat_fs_info_t *fs_info, uint32_t cln ) { if ( (cln == 0) && (fs_info->vol.type & (FAT_FAT12 | FAT_FAT16)) ) return fs_info->vol.rdir_loc; return (((cln - FAT_RSRVD_CLN) << fs_info->vol.spc_log2) + fs_info->vol.data_fsec); } static inline uint32_t fat_cluster_num_to_sector512_num( const fat_fs_info_t *fs_info, uint32_t cln ) { if (cln == 1) return 1; return (fat_cluster_num_to_sector_num(fs_info, cln) << fs_info->vol.sec_mul); } static inline uint32_t fat_block_num_to_cluster_num (const fat_fs_info_t *fs_info, const uint32_t block_number) { return block_number >> (fs_info->vol.bpc_log2 - fs_info->vol.bytes_per_block_log2); } static inline uint32_t fat_block_num_to_sector_num (const fat_fs_info_t *fs_info, const uint32_t block_number) { return block_number << (fs_info->vol.bytes_per_block_log2 - fs_info->vol.sec_log2); } static inline uint32_t fat_sector_num_to_block_num (const fat_fs_info_t *fs_info, const uint32_t sector_number) { return sector_number >> (fs_info->vol.bytes_per_block_log2 - fs_info->vol.sec_log2); } static inline uint32_t fat_sector_offset_to_block_offset (const fat_fs_info_t *fs_info, const uint32_t sector, const uint32_t sector_offset) { return sector_offset + ((sector - fat_block_num_to_sector_num (fs_info, fat_sector_num_to_block_num (fs_info, sector))) << fs_info->vol.sec_log2); } static inline void fat_buf_mark_modified(fat_fs_info_t *fs_info) { fs_info->c.modified = true; } int fat_buf_access(fat_fs_info_t *fs_info, uint32_t sec_num, int op_type, uint8_t **sec_buf); int fat_buf_release(fat_fs_info_t *fs_info); ssize_t _fat_block_read(fat_fs_info_t *fs_info, uint32_t start, uint32_t offset, uint32_t count, void *buff); ssize_t fat_cluster_write(fat_fs_info_t *fs_info, uint32_t start_cln, uint32_t offset, uint32_t count, const void *buff, bool overwrite_cluster); ssize_t fat_sector_write(fat_fs_info_t *fs_info, uint32_t start, uint32_t offset, uint32_t count, const void *buff); ssize_t fat_cluster_set(fat_fs_info_t *fs_info, uint32_t start, uint32_t offset, uint32_t count, uint8_t pattern); int fat_init_volume_info(fat_fs_info_t *fs_info, const char *device); int fat_init_clusters_chain(fat_fs_info_t *fs_info, uint32_t start_cln); int fat_shutdown_drive(fat_fs_info_t *fs_info); uint32_t fat_get_unique_ino(fat_fs_info_t *fs_info); bool fat_ino_is_unique(fat_fs_info_t *fs_info, uint32_t ino); void fat_free_unique_ino(fat_fs_info_t *fs_info, uint32_t ino); int fat_sync(fat_fs_info_t *fs_info); #ifdef __cplusplus } #endif /**@}*/ #endif /* __DOSFS_FAT_H__ */