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/*
libparted
Copyright (C) 1998-2000, 2007, 2009-2014, 2019-2022 Free Software
Foundation, Inc.
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/>.
*/
#ifndef PED_FAT_BOOTSECTOR_H
#define PED_FAT_BOOTSECTOR_H
typedef struct _FatBootSector FatBootSector;
typedef struct _FatInfoSector FatInfoSector;
#include "fat.h"
#define FAT32_INFO_MAGIC1 0x41615252
#define FAT32_INFO_MAGIC2 0x61417272
#define FAT32_INFO_MAGIC3 0xaa55
/* stolen from mkdosfs, by Dave Hudson */
#define FAT_BOOT_MESSAGE \
"This partition does not have an operating system loader installed on it.\n\r"\
"Press a key to reboot..."
#define FAT_BOOT_JUMP "\xeb\x58\x90" /* jmp +5a */
#define FAT_BOOT_CODE "\x0e" /* push cs */ \
"\x1f" /* pop ds */ \
"\xbe\x74\x7e" /* mov si, offset message */ \
/* write_msg_loop: */ \
"\xac" /* lodsb */ \
"\x22\xc0" /* and al, al */ \
"\x74\x06" /* jz done (+8) */ \
"\xb4\x0e" /* mov ah, 0x0e */ \
"\xcd\x10" /* int 0x10 */ \
"\xeb\xf5" /* jmp write_msg_loop */ \
/* done: */ \
"\xb4\x00" /* mov ah, 0x00 */ \
"\xcd\x16" /* int 0x16 */ \
"\xb4\x00" /* mov ah, 0x00 */ \
"\xcd\x19" /* int 0x19 */ \
"\xeb\xfe" /* jmp +0 - in case int 0x19 */ \
/* doesn't work */ \
/* message: */ \
FAT_BOOT_MESSAGE
#define FAT_BOOT_CODE_LENGTH 128
struct __attribute__ ((packed)) _FatBootSector {
uint8_t boot_jump[3]; /* 00: Boot strap short or near jump */
uint8_t system_id[8]; /* 03: system name */
uint16_t sector_size; /* 0b: bytes per logical sector */
uint8_t cluster_size; /* 0d: sectors/cluster */
uint16_t reserved; /* 0e: reserved sectors */
uint8_t fats; /* 10: number of FATs */
uint16_t dir_entries; /* 11: number of root directory entries */
uint16_t sectors; /* 13: if 0, total_sect supersedes */
uint8_t media; /* 15: media code */
uint16_t fat_length; /* 16: sectors/FAT for FAT12/16 */
uint16_t secs_track; /* 18: sectors per track */
uint16_t heads; /* 1a: number of heads */
uint32_t hidden; /* 1c: hidden sectors (partition start) */
uint32_t sector_count; /* 20: no. of sectors (if sectors == 0) */
union __attribute__ ((packed)) {
/* FAT16 fields */
struct __attribute__ ((packed)) {
uint8_t drive_num; /* 24: */
uint8_t empty_1; /* 25: */
uint8_t ext_signature; /* 26: always 0x29 */
uint32_t serial_number; /* 27: */
uint8_t volume_name [11]; /* 2b: */
uint8_t fat_name [8]; /* 36: */
uint8_t boot_code[448]; /* 3f: Boot code (or message) */
} fat16;
/* FAT32 fields */
struct __attribute__ ((packed)) {
uint32_t fat_length; /* 24: size of FAT in sectors */
uint16_t flags; /* 28: bit8: fat mirroring, low4: active fat */
uint16_t version; /* 2a: minor * 256 + major */
uint32_t root_dir_cluster; /* 2c: */
uint16_t info_sector; /* 30: */
uint16_t backup_sector; /* 32: */
uint8_t empty_1 [12]; /* 34: */
uint16_t drive_num; /* 40: */
uint8_t ext_signature; /* 42: always 0x29 */
uint32_t serial_number; /* 43: */
uint8_t volume_name [11]; /* 47: */
uint8_t fat_name [8]; /* 52: */
uint8_t boot_code[420]; /* 5a: Boot code (or message) */
} fat32;
} u;
uint16_t boot_sign; /* 1fe: always 0xAA55 */
};
struct __attribute__ ((packed)) _FatInfoSector {
uint32_t signature_1; /* should be 0x41615252 */
uint8_t unused [480];
uint32_t signature_2; /* should be 0x61417272 */
uint32_t free_clusters;
uint32_t next_cluster; /* most recently allocated cluster */
uint8_t unused2 [0xe];
uint16_t signature_3; /* should be 0xaa55 */
};
int fat_boot_sector_read (FatBootSector** bs, const PedGeometry* geom);
FatType fat_boot_sector_probe_type (const FatBootSector* bs,
const PedGeometry* geom);
int fat_boot_sector_analyse (FatBootSector* bs, PedFileSystem* fs);
#endif /* PED_FAT_BOOTSECTOR_H */
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