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#ifndef FAT_FS_H
#define FAT_FS_H
#include <stdint.h>
#define FAT_DIR_ENTRY_SIZE 32
#define DIRENT_SHIFT 5
#define FAT_ATTR_READ_ONLY 0x01
#define FAT_ATTR_HIDDEN 0x02
#define FAT_ATTR_SYSTEM 0x04
#define FAT_ATTR_VOLUME_ID 0x08
#define FAT_ATTR_DIRECTORY 0x10
#define FAT_ATTR_ARCHIVE 0x20
#define FAT_MAXFILE 256
#define FAT_ATTR_LONG_NAME (FAT_ATTR_READ_ONLY \
| FAT_ATTR_HIDDEN \
| FAT_ATTR_SYSTEM \
| FAT_ATTR_VOLUME_ID)
#define FAT_ATTR_VALID (FAT_ATTR_READ_ONLY \
| FAT_ATTR_HIDDEN \
| FAT_ATTR_SYSTEM \
| FAT_ATTR_DIRECTORY \
| FAT_ATTR_ARCHIVE)
enum fat_type{ FAT12, FAT16, FAT32 };
/*
* The fat file system structures
*/
struct fat_bpb {
uint8_t jmp_boot[3];
uint8_t oem_name[8];
uint16_t sector_size;
uint8_t bxSecPerClust;
uint16_t bxResSectors;
uint8_t bxFATs;
uint16_t bxRootDirEnts;
uint16_t bxSectors;
uint8_t media;
uint16_t bxFATsecs;
uint16_t sectors_per_track;
uint16_t num_heads;
uint32_t num_hidden_sectors;
uint32_t bsHugeSectors;
union {
struct {
uint8_t num_ph_drive;
uint8_t reserved;
uint8_t boot_sig;
uint32_t num_serial;
uint8_t label[11];
uint8_t fstype[8];
} __attribute__ ((packed)) fat12_16;
struct {
uint32_t bxFATsecs_32;
uint16_t extended_flags;
uint16_t fs_version;
uint32_t root_cluster;
uint16_t fs_info;
uint16_t backup_boot_sector;
uint8_t reserved[12];
uint8_t num_ph_drive;
uint8_t reserved1;
uint8_t boot_sig;
uint32_t num_serial;
uint8_t label[11];
uint8_t fstype[8];
} __attribute__ ((packed)) fat32;
} __attribute__ ((packed));
uint8_t pad[422]; /* padding to 512 Bytes (one sector) */
} __attribute__ ((packed));
/*
* The fat file system info in memory
*/
struct fat_sb_info {
sector_t fat; /* The FAT region */
sector_t root; /* The root dir region */
sector_t data; /* The data region */
uint32_t clusters; /* Total number of clusters */
uint32_t root_cluster; /* Cluster number for (FAT32) root dir */
int root_size; /* The root dir size in sectors */
int clust_shift; /* based on sectors */
int clust_byte_shift; /* based on bytes */
int clust_mask; /* sectors per cluster mask */
int clust_size;
int fat_type;
} __attribute__ ((packed));
struct fat_dir_entry {
char name[11];
uint8_t attr;
uint8_t lcase;
uint8_t c_time_tenth;
uint16_t c_time;
uint16_t c_date;
uint16_t a_date;
uint16_t first_cluster_high;
uint16_t w_time;
uint16_t w_date;
uint16_t first_cluster_low;
uint32_t file_size;
} __attribute__ ((packed));
#define LCASE_BASE 8 /* basename is lower case */
#define LCASE_EXT 16 /* extension is lower case */
struct fat_long_name_entry {
uint8_t id;
uint16_t name1[5];
uint8_t attr;
uint8_t reserved;
uint8_t checksum;
uint16_t name2[6];
uint16_t first_cluster;
uint16_t name3[2];
} __attribute__ ((packed));
static inline struct fat_sb_info *FAT_SB(struct fs_info *fs)
{
return fs->fs_info;
}
/*
* Count the root dir size in sectors
*/
static inline int root_dir_size(struct fs_info *fs, struct fat_bpb *fat)
{
return (fat->bxRootDirEnts + SECTOR_SIZE(fs)/32 - 1)
>> (SECTOR_SHIFT(fs) - 5);
}
/*
* FAT private inode information
*/
struct fat_pvt_inode {
uint32_t start_cluster; /* Starting cluster address */
sector_t start; /* Starting sector */
sector_t offset; /* Current sector offset */
sector_t here; /* Sector corresponding to offset */
};
#define PVT(i) ((struct fat_pvt_inode *)((i)->pvt))
#endif /* fat_fs.h */
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