/* msdos_fs.h - MS-DOS filesystem constants/structures
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
The complete text of the GNU General Public License
can be found in /usr/share/common-licenses/GPL-3 file.
*/
#ifndef _MSDOS_FS_H
#define _MSDOS_FS_H
#include <stdint.h>
#define SECTOR_SIZE 512 /* sector size (bytes) */
#define MSDOS_DPS (SECTOR_SIZE / sizeof(struct msdos_dir_entry))
#define MSDOS_DPS_BITS 4 /* log2(MSDOS_DPS) */
#define MSDOS_DIR_BITS 5 /* log2(sizeof(struct msdos_dir_entry)) */
#define ATTR_NONE 0 /* no attribute bits */
#define ATTR_RO 1 /* read-only */
#define ATTR_HIDDEN 2 /* hidden */
#define ATTR_SYS 4 /* system */
#define ATTR_VOLUME 8 /* volume label */
#define ATTR_DIR 16 /* directory */
#define ATTR_ARCH 32 /* archived */
/* attribute bits that are copied "as is" */
#define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
#define DELETED_FLAG 0xe5 /* marks file as deleted when in name[0] */
#define IS_FREE(n) (!*(n) || *(n) == DELETED_FLAG)
#define MSDOS_NAME 11 /* maximum name length */
#define MSDOS_DOT ". " /* ".", padded to MSDOS_NAME chars */
#define MSDOS_DOTDOT ".. " /* "..", padded to MSDOS_NAME chars */
struct msdos_dir_entry {
uint8_t name[MSDOS_NAME]; /* name including extension */
uint8_t attr; /* attribute bits */
uint8_t lcase; /* Case for base and extension */
uint8_t ctime_cs; /* Creation time, centiseconds (0-199) */
uint16_t ctime; /* Creation time */
uint16_t cdate; /* Creation date */
uint16_t adate; /* Last access date */
uint16_t starthi; /* High 16 bits of cluster in FAT32 */
uint16_t time, date, start; /* time, date and first cluster */
uint32_t size; /* file size (in bytes) */
} __attribute__ ((packed));
#endif /* _MSDOS_FS_H */