/*
* 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 */
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(
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_zero(rtems_filesystem_mount_table_entry_t *mt_entry,
uint32_t start,
uint32_t offset,
uint32_t count);
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__ */