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/* $OpenBSD: bpb.h,v 1.1 2016/10/18 17:05:30 natano Exp $ */
/* $NetBSD: bpb.h,v 1.8 2016/01/22 22:53:36 dholland Exp $ */
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
#ifndef _MSDOSFS_BPB_H_
#define _MSDOSFS_BPB_H_
/*
* BIOS Parameter Block (BPB) for DOS 3.3
*/
struct bpb33 {
uint16_t bpbBytesPerSec; /* bytes per sector */
uint8_t bpbSecPerClust; /* sectors per cluster */
uint16_t bpbResSectors; /* number of reserved sectors */
uint8_t bpbFATs; /* number of FATs */
uint16_t bpbRootDirEnts; /* number of root directory entries */
uint16_t bpbSectors; /* total number of sectors */
uint8_t bpbMedia; /* media descriptor */
uint16_t bpbFATsecs; /* number of sectors per FAT */
uint16_t bpbSecPerTrack; /* sectors per track */
uint16_t bpbHeads; /* number of heads */
uint16_t bpbHiddenSecs; /* number of hidden sectors */
};
/*
* BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3,
* and bpbHugeSectors is not in the 3.3 bpb.
*/
struct bpb50 {
uint16_t bpbBytesPerSec; /* bytes per sector */
uint8_t bpbSecPerClust; /* sectors per cluster */
uint16_t bpbResSectors; /* number of reserved sectors */
uint8_t bpbFATs; /* number of FATs */
uint16_t bpbRootDirEnts; /* number of root directory entries */
uint16_t bpbSectors; /* total number of sectors */
uint8_t bpbMedia; /* media descriptor */
uint16_t bpbFATsecs; /* number of sectors per FAT */
uint16_t bpbSecPerTrack; /* sectors per track */
uint16_t bpbHeads; /* number of heads */
uint32_t bpbHiddenSecs; /* # of hidden sectors */
uint32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
};
/*
* BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
*/
struct bpb710 {
uint16_t bpbBytesPerSec; /* bytes per sector */
uint8_t bpbSecPerClust; /* sectors per cluster */
uint16_t bpbResSectors; /* number of reserved sectors */
uint8_t bpbFATs; /* number of FATs */
uint16_t bpbRootDirEnts; /* number of root directory entries */
uint16_t bpbSectors; /* total number of sectors */
uint8_t bpbMedia; /* media descriptor */
uint16_t bpbFATsecs; /* number of sectors per FAT */
uint16_t bpbSecPerTrack; /* sectors per track */
uint16_t bpbHeads; /* number of heads */
uint32_t bpbHiddenSecs; /* # of hidden sectors */
uint32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
uint32_t bpbBigFATsecs; /* like bpbFATsecs for FAT32 */
uint16_t bpbExtFlags; /* extended flags: */
#define FATNUM 0xf /* mask for numbering active FAT */
#define FATMIRROR 0x80 /* FAT is mirrored (like it always was) */
uint16_t bpbFSVers; /* filesystem version */
#define FSVERS 0 /* currently only 0 is understood */
uint32_t bpbRootClust; /* start cluster for root directory */
uint16_t bpbFSInfo; /* filesystem info structure sector */
uint16_t bpbBackup; /* backup boot sector */
uint8_t bpbReserved[12]; /* Reserved for future expansion */
};
/*
* The following structures represent how the bpb's look on disk. shorts
* and longs are just character arrays of the appropriate length. This is
* because the compiler forces shorts and longs to align on word or
* halfword boundaries.
*
* XXX The little-endian code here assumes that the processor can access
* 16-bit and 32-bit quantities on byte boundaries. If this is not true,
* use the macros for the big-endian case.
*/
#include <sys/endian.h>
#if (BYTE_ORDER == LITTLE_ENDIAN) && !defined(__STRICT_ALIGNMENT)
#define getushort(x) *((u_int16_t *)(x))
#define getulong(x) *((u_int32_t *)(x))
#define putushort(p, v) (*((u_int16_t *)(p)) = (v))
#define putulong(p, v) (*((u_int32_t *)(p)) = (v))
#else
#define getushort(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8))
#define getulong(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8) \
+ (((u_int8_t *)(x))[2] << 16) \
+ (((u_int8_t *)(x))[3] << 24))
#define putushort(p, v) (((u_int8_t *)(p))[0] = (v), \
((u_int8_t *)(p))[1] = (v) >> 8)
#define putulong(p, v) (((u_int8_t *)(p))[0] = (v), \
((u_int8_t *)(p))[1] = (v) >> 8, \
((u_int8_t *)(p))[2] = (v) >> 16,\
((u_int8_t *)(p))[3] = (v) >> 24)
#endif
/*
* BIOS Parameter Block (BPB) for DOS 3.3
*/
struct byte_bpb33 {
int8_t bpbBytesPerSec[2]; /* bytes per sector */
int8_t bpbSecPerClust; /* sectors per cluster */
int8_t bpbResSectors[2]; /* number of reserved sectors */
int8_t bpbFATs; /* number of FATs */
int8_t bpbRootDirEnts[2]; /* number of root directory entries */
int8_t bpbSectors[2]; /* total number of sectors */
int8_t bpbMedia; /* media descriptor */
int8_t bpbFATsecs[2]; /* number of sectors per FAT */
int8_t bpbSecPerTrack[2]; /* sectors per track */
int8_t bpbHeads[2]; /* number of heads */
int8_t bpbHiddenSecs[2]; /* number of hidden sectors */
};
/*
* BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3,
* and bpbHugeSectors is not in the 3.3 bpb.
*/
struct byte_bpb50 {
int8_t bpbBytesPerSec[2]; /* bytes per sector */
int8_t bpbSecPerClust; /* sectors per cluster */
int8_t bpbResSectors[2]; /* number of reserved sectors */
int8_t bpbFATs; /* number of FATs */
int8_t bpbRootDirEnts[2]; /* number of root directory entries */
int8_t bpbSectors[2]; /* total number of sectors */
int8_t bpbMedia; /* media descriptor */
int8_t bpbFATsecs[2]; /* number of sectors per FAT */
int8_t bpbSecPerTrack[2]; /* sectors per track */
int8_t bpbHeads[2]; /* number of heads */
int8_t bpbHiddenSecs[4]; /* number of hidden sectors */
int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */
};
/*
* BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
*/
struct byte_bpb710 {
uint8_t bpbBytesPerSec[2]; /* bytes per sector */
uint8_t bpbSecPerClust; /* sectors per cluster */
uint8_t bpbResSectors[2]; /* number of reserved sectors */
uint8_t bpbFATs; /* number of FATs */
uint8_t bpbRootDirEnts[2]; /* number of root directory entries */
uint8_t bpbSectors[2]; /* total number of sectors */
uint8_t bpbMedia; /* media descriptor */
uint8_t bpbFATsecs[2]; /* number of sectors per FAT */
uint8_t bpbSecPerTrack[2]; /* sectors per track */
uint8_t bpbHeads[2]; /* number of heads */
uint8_t bpbHiddenSecs[4]; /* # of hidden sectors */
uint8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */
uint8_t bpbBigFATsecs[4]; /* like bpbFATsecs for FAT32 */
uint8_t bpbExtFlags[2]; /* extended flags: */
uint8_t bpbFSVers[2]; /* filesystem version */
uint8_t bpbRootClust[4]; /* start cluster for root directory */
uint8_t bpbFSInfo[2]; /* filesystem info structure sector */
uint8_t bpbBackup[2]; /* backup boot sector */
uint8_t bpbReserved[12]; /* Reserved for future expansion */
};
/*
* FAT32 FSInfo block.
*/
struct fsinfo {
uint8_t fsisig1[4];
uint8_t fsifill1[480];
uint8_t fsisig2[4];
uint8_t fsinfree[4];
uint8_t fsinxtfree[4];
uint8_t fsifill2[12];
uint8_t fsisig3[4];
uint8_t fsifill3[508];
uint8_t fsisig4[4];
};
#endif /* _MSDOSFS_BPB_H_ */
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