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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2001 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 2 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
/*
* Defines for the FAT BIOS Parameter Block (embedded in the first block
* of the partition.
*/
typedef __signed__ char __s8;
typedef unsigned char __u8;
typedef __signed__ short __s16;
typedef unsigned short __u16;
typedef __signed__ int __s32;
typedef unsigned int __u32;
/* Note that some shorts are not aligned, and must therefore
* be declared as array of two bytes.
*/
struct fat_bpb {
__s8 ignored[3]; /* Boot strap short or near jump */
__s8 system_id[8]; /* Name - can be used to special case
partition manager volumes */
__u16 bytes_per_sect; /* bytes per logical sector */
__u8 sects_per_clust;/* sectors/cluster */
__u16 reserved_sects; /* reserved sectors */
__u8 num_fats; /* number of FATs */
__u16 dir_entries; /* root directory entries */
__u16 short_sectors; /* number of sectors */
__u8 media; /* media code (unused) */
__u16 fat_length; /* sectors/FAT */
__u16 secs_track; /* sectors per track */
__u16 heads; /* number of heads */
__u32 hidden; /* hidden sectors (unused) */
__u32 long_sectors; /* number of sectors (if short_sectors == 0) */
/* The following fields are only used by FAT32 */
__u32 fat32_length; /* sectors/FAT */
__u16 flags; /* bit 8: fat mirroring, low 4: active fat */
__u16 version; /* major, minor filesystem version */
__u32 root_cluster; /* first cluster in root directory */
__u16 info_sector; /* filesystem info sector */
__u16 backup_boot; /* backup boot sector */
__u16 reserved2[6]; /* Unused */
} __attribute__ ((packed));
/*
* Defines how to differentiate a 12-bit and 16-bit FAT.
*/
#define FAT_MAX_12BIT_CLUST 4087 /* 4085 + 2 */
/*
* Defines for the file "attribute" byte
*/
#define FAT_ATTRIB_OK_MASK 0x37
#define FAT_ATTRIB_NOT_OK_MASK 0xC8
#define FAT_ATTRIB_DIR 0x10
#define FAT_ATTRIB_LONGNAME 0x0F
/*
* Defines for FAT directory entries
*/
#define FAT_DIRENTRY_LENGTH 32
#define FAT_DIRENTRY_ATTRIB(entry) \
(*((unsigned char *) (entry+11)))
#define FAT_DIRENTRY_VALID(entry) \
( ((*((unsigned char *) entry)) != 0) \
&& ((*((unsigned char *) entry)) != 0xE5) \
&& !(FAT_DIRENTRY_ATTRIB(entry) & FAT_ATTRIB_NOT_OK_MASK) )
#define FAT_DIRENTRY_FIRST_CLUSTER(entry) \
((*((unsigned short *) (entry+26)))+(*((unsigned short *) (entry+20)) << 16))
#define FAT_DIRENTRY_FILELENGTH(entry) \
(*((unsigned long *) (entry+28)))
#define FAT_LONGDIR_ID(entry) \
(*((unsigned char *) (entry)))
#define FAT_LONGDIR_ALIASCHECKSUM(entry) \
(*((unsigned char *) (entry+13)))
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