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CervusOS/kernel/include/fs/fat32.h
T
alexvoste 1a9fd27a31 push
2026-05-07 02:22:25 +03:00

146 lines
3.8 KiB
C

#ifndef FAT32_H
#define FAT32_H
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include "../drivers/blkdev.h"
#include "vfs.h"
#define FAT32_SECTOR_SIZE 512
#define FAT32_EOC 0x0FFFFFFF
#define FAT32_EOC_MIN 0x0FFFFFF8
#define FAT32_FREE_CLUSTER 0x00000000
#define FAT32_BAD_CLUSTER 0x0FFFFFF7
#define FAT32_CLUSTER_MASK 0x0FFFFFFF
#define FAT32_FSINFO_LEAD_SIG 0x41615252
#define FAT32_FSINFO_STRUCT_SIG 0x61417272
#define FAT32_FSINFO_TRAIL_SIG 0xAA550000
#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_ATTR_LONG_NAME 0x0F
typedef struct __attribute__((packed)) {
uint8_t bs_jmp[3];
uint8_t bs_oem[8];
uint16_t bpb_bytes_per_sector;
uint8_t bpb_sectors_per_cluster;
uint16_t bpb_reserved_sectors;
uint8_t bpb_num_fats;
uint16_t bpb_root_entries;
uint16_t bpb_total_sectors_16;
uint8_t bpb_media;
uint16_t bpb_fat_size_16;
uint16_t bpb_sectors_per_track;
uint16_t bpb_num_heads;
uint32_t bpb_hidden_sectors;
uint32_t bpb_total_sectors_32;
uint32_t bpb_fat_size_32;
uint16_t bpb_ext_flags;
uint16_t bpb_fs_version;
uint32_t bpb_root_cluster;
uint16_t bpb_fs_info;
uint16_t bpb_backup_boot;
uint8_t bpb_reserved[12];
uint8_t bs_drive_num;
uint8_t bs_reserved1;
uint8_t bs_boot_sig;
uint32_t bs_vol_id;
uint8_t bs_vol_label[11];
uint8_t bs_fs_type[8];
uint8_t bs_boot_code[420];
uint16_t bs_signature;
} fat32_bpb_t;
_Static_assert(sizeof(fat32_bpb_t) == 512, "fat32 bpb size");
typedef struct __attribute__((packed)) {
uint32_t lead_sig;
uint8_t reserved1[480];
uint32_t struct_sig;
uint32_t free_count;
uint32_t next_free;
uint8_t reserved2[12];
uint32_t trail_sig;
} fat32_fsinfo_t;
_Static_assert(sizeof(fat32_fsinfo_t) == 512, "fat32 fsinfo size");
typedef struct __attribute__((packed)) {
uint8_t name[11];
uint8_t attr;
uint8_t nt_reserved;
uint8_t create_time_tenth;
uint16_t create_time;
uint16_t create_date;
uint16_t access_date;
uint16_t cluster_hi;
uint16_t modify_time;
uint16_t modify_date;
uint16_t cluster_lo;
uint32_t file_size;
} fat32_dirent_t;
_Static_assert(sizeof(fat32_dirent_t) == 32, "fat32 dirent size");
typedef struct __attribute__((packed)) {
uint8_t order;
uint8_t name1[10];
uint8_t attr;
uint8_t type;
uint8_t checksum;
uint8_t name2[12];
uint16_t cluster_lo;
uint8_t name3[4];
} fat32_lfn_t;
_Static_assert(sizeof(fat32_lfn_t) == 32, "fat32 lfn size");
typedef struct {
blkdev_t *dev;
uint32_t bytes_per_sector;
uint32_t sectors_per_cluster;
uint32_t bytes_per_cluster;
uint32_t reserved_sectors;
uint32_t num_fats;
uint32_t fat_size_sectors;
uint32_t total_sectors;
uint32_t root_cluster;
uint32_t first_fat_sector;
uint32_t first_data_sector;
uint32_t total_clusters;
uint32_t fsinfo_sector;
uint32_t next_free_hint;
uint32_t free_count;
bool dirty;
bool readonly;
uint8_t *shared_buf;
} fat32_t;
typedef struct {
fat32_t *fs;
uint32_t first_cluster;
uint32_t dir_cluster;
uint32_t dir_entry_offset;
uint32_t file_size;
uint8_t attr;
uint32_t cached_cluster;
uint32_t cached_index;
bool size_dirty;
uint8_t *io_buf;
} fat32_vdata_t;
int fat32_format(blkdev_t *dev, const char *label);
vnode_t *fat32_mount(blkdev_t *dev);
void fat32_unmount(fat32_t *fs);
int fat32_sync(fat32_t *fs);
#endif