125 lines
3.1 KiB
C
125 lines
3.1 KiB
C
/*
|
|
* Copyright (c) 2023 Jonas 'Sortie' Termansen.
|
|
*
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*
|
|
* fat.h
|
|
* The File Allocation Table (FAT) filesystem.
|
|
*/
|
|
|
|
#ifndef FAT_H
|
|
#define FAT_H
|
|
|
|
#include <assert.h>
|
|
#include <stdint.h>
|
|
|
|
// TODO: Dammit. I forgot to swap endian all across the codebase.
|
|
|
|
struct fat_bpb
|
|
{
|
|
uint8_t jump[3];
|
|
char oem[8];
|
|
uint8_t bytes_per_sector_low;
|
|
uint8_t bytes_per_sector_high;
|
|
uint8_t sectors_per_cluster;
|
|
uint16_t reserved_sectors;
|
|
uint8_t fat_count;
|
|
uint8_t root_dirent_count_low;
|
|
uint8_t root_dirent_count_high;
|
|
uint8_t total_sectors_low;
|
|
uint8_t total_sectors_high;
|
|
uint8_t media_descriptor_type;
|
|
uint16_t sectors_per_fat;
|
|
uint16_t sectors_per_track;
|
|
uint16_t head_count;
|
|
uint16_t hidden_sectors;
|
|
uint32_t total_sectors_large;
|
|
union
|
|
{
|
|
struct
|
|
{
|
|
uint8_t fat12_drive_number;
|
|
uint8_t fat12_reserved;
|
|
uint8_t fat12_signature;
|
|
uint8_t fat12_volume_id[4];
|
|
uint8_t fat12_volume_label[11];
|
|
uint8_t fat12_system[8];
|
|
};
|
|
struct
|
|
{
|
|
uint32_t fat32_sectors_per_fat;
|
|
uint16_t fat32_flags;
|
|
uint16_t fat32_version;
|
|
uint32_t fat32_root_cluster;
|
|
uint16_t fat32_fsinfo;
|
|
uint16_t fat32_backup_boot;
|
|
uint32_t fat32_reserved1[3];
|
|
uint8_t fat32_drive_number;
|
|
uint8_t fat32_reserved2;
|
|
uint8_t fat32_signature;
|
|
uint8_t fat32_volume_id[4];
|
|
uint8_t fat32_volume_label[11];
|
|
uint8_t fat32_system[8];
|
|
};
|
|
struct
|
|
{
|
|
uint8_t bootloader[510 - 36];
|
|
uint8_t boot_signature[2];
|
|
};
|
|
};
|
|
};
|
|
|
|
static_assert(sizeof(struct fat_bpb) == 512, "sizeof(struct fat_bpb) == 512");
|
|
|
|
struct fat_fsinfo
|
|
{
|
|
uint32_t signature1;
|
|
uint32_t reserved1[120];
|
|
uint32_t signature2;
|
|
uint32_t free_count;
|
|
uint32_t next_free;
|
|
uint32_t reserved2[3];
|
|
uint32_t signature3;
|
|
};
|
|
|
|
static_assert(sizeof(struct fat_fsinfo) == 512, "sizeof(struct fat_fsinfo) == 512");
|
|
|
|
struct fat_dirent
|
|
{
|
|
char name[11];
|
|
uint8_t attributes;
|
|
uint8_t reserved;
|
|
uint8_t creation_tenths; // TODO: Misnamed semantically.
|
|
uint16_t creation_time;
|
|
uint16_t creation_date;
|
|
uint16_t access_date;
|
|
uint16_t cluster_high;
|
|
uint16_t modified_time;
|
|
uint16_t modified_date;
|
|
uint16_t cluster_low;
|
|
uint32_t size;
|
|
};
|
|
|
|
static_assert(sizeof(struct fat_dirent) == 32, "sizeof(struct fat_dirent) == 32");
|
|
|
|
#define FAT_ATTRIBUTE_READ_ONLY (1 << 0)
|
|
#define FAT_ATTRIBUTE_HIDDEN (1 << 1)
|
|
#define FAT_ATTRIBUTE_SYSTEM (1 << 2)
|
|
#define FAT_ATTRIBUTE_VOLUME_ID (1 << 3)
|
|
#define FAT_ATTRIBUTE_DIRECTORY (1 << 4)
|
|
#define FAT_ATTRIBUTE_ARCHIVE (1 << 5)
|
|
|
|
#define FAT_ATTRIBUTE_LONG_NAME 0x0F
|
|
|
|
#endif
|