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Diffstat (limited to 'cpukit/libfs/src/dosfs/fat.h')
| -rw-r--r-- | cpukit/libfs/src/dosfs/fat.h | 517 |
1 files changed, 517 insertions, 0 deletions
diff --git a/cpukit/libfs/src/dosfs/fat.h b/cpukit/libfs/src/dosfs/fat.h new file mode 100644 index 0000000000..8d62662c10 --- /dev/null +++ b/cpukit/libfs/src/dosfs/fat.h @@ -0,0 +1,517 @@ +/* + * fat.h + * + * 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 <Eugeny.Mints@oktet.ru> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * @(#) $Id$ + */ + +#ifndef __DOSFS_FAT_H__ +#define __DOSFS_FAT_H__ + +#include <string.h> + +#include <rtems/seterr.h> + +#include <rtems/score/cpu.h> +#include <errno.h> +#include <rtems/bdbuf.h> + +#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 MIN(a, b) (((a) < (b)) ? (a) : (b)) + +#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 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 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 next_cl; /* next free cluster number */ + uint8_t mirror; /* mirroring enabla/disable */ + uint32_t afat_loc; /* active FAT location */ + uint8_t afat; /* the number of active FAT */ + dev_t dev; /* device ID */ + 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( + rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t cln + ) +{ + register fat_fs_info_t *fs_info = mt_entry->fs_info; + + 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( + rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t cln + ) +{ + fat_fs_info_t *fs_info = mt_entry->fs_info; + + if (cln == 1) + return 1; + + return (fat_cluster_num_to_sector_num(mt_entry, cln) << + fs_info->vol.sec_mul); +} + +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 blk, int op_type, + rtems_bdbuf_buffer **buf); + +int +fat_buf_release(fat_fs_info_t *fs_info); + +ssize_t +_fat_block_read(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t start, + uint32_t offset, + uint32_t count, + void *buff); + +ssize_t +_fat_block_write(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t start, + uint32_t offset, + uint32_t count, + const void *buff); + +int +_fat_block_release(rtems_filesystem_mount_table_entry_t *mt_entry); + +ssize_t +fat_cluster_read(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t cln, + void *buff); + +ssize_t +fat_cluster_write(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t cln, + const void *buff); + +int +fat_init_volume_info(rtems_filesystem_mount_table_entry_t *mt_entry); + +int +fat_init_clusters_chain(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t start_cln); + +uint32_t +fat_cluster_num_to_sector_num(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t cln); + +int +fat_shutdown_drive(rtems_filesystem_mount_table_entry_t *mt_entry); + + +uint32_t +fat_get_unique_ino(rtems_filesystem_mount_table_entry_t *mt_entry); + +bool +fat_ino_is_unique(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t ino); + +void +fat_free_unique_ino(rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t ino); + +int +fat_fat32_update_fsinfo_sector( + rtems_filesystem_mount_table_entry_t *mt_entry, + uint32_t free_count, + uint32_t next_free + ); + +#ifdef __cplusplus +} +#endif + +#endif /* __DOSFS_FAT_H__ */ |