freebsd-nq/sys/fs/msdosfs/bpb.h
Marcel Moolenaar 94632b9fe1 Unbreak 64-bit little-endian systems that do require alignment.
The fix involves using le16dec(), le32dec(), le16enc() and
le32enc(). This eliminates invalid casts and duplicated logic.
2006-12-21 05:40:46 +00:00

177 lines
6.5 KiB
C

/* $FreeBSD$ */
/* $NetBSD: bpb.h,v 1.7 1997/11/17 15:36:24 ws 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
*/
/*
* BIOS Parameter Block (BPB) for DOS 3.3
*/
struct bpb33 {
u_int16_t bpbBytesPerSec; /* bytes per sector */
u_int8_t bpbSecPerClust; /* sectors per cluster */
u_int16_t bpbResSectors; /* number of reserved sectors */
u_int8_t bpbFATs; /* number of FATs */
u_int16_t bpbRootDirEnts; /* number of root directory entries */
u_int16_t bpbSectors; /* total number of sectors */
u_int8_t bpbMedia; /* media descriptor */
u_int16_t bpbFATsecs; /* number of sectors per FAT */
u_int16_t bpbSecPerTrack; /* sectors per track */
u_int16_t bpbHeads; /* number of heads */
u_int16_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 {
u_int16_t bpbBytesPerSec; /* bytes per sector */
u_int8_t bpbSecPerClust; /* sectors per cluster */
u_int16_t bpbResSectors; /* number of reserved sectors */
u_int8_t bpbFATs; /* number of FATs */
u_int16_t bpbRootDirEnts; /* number of root directory entries */
u_int16_t bpbSectors; /* total number of sectors */
u_int8_t bpbMedia; /* media descriptor */
u_int16_t bpbFATsecs; /* number of sectors per FAT */
u_int16_t bpbSecPerTrack; /* sectors per track */
u_int16_t bpbHeads; /* number of heads */
u_int32_t bpbHiddenSecs; /* # of hidden sectors */
u_int32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
};
/*
* BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50.
*/
struct bpb710 {
u_int16_t bpbBytesPerSec; /* bytes per sector */
u_int8_t bpbSecPerClust; /* sectors per cluster */
u_int16_t bpbResSectors; /* number of reserved sectors */
u_int8_t bpbFATs; /* number of FATs */
u_int16_t bpbRootDirEnts; /* number of root directory entries */
u_int16_t bpbSectors; /* total number of sectors */
u_int8_t bpbMedia; /* media descriptor */
u_int16_t bpbFATsecs; /* number of sectors per FAT */
u_int16_t bpbSecPerTrack; /* sectors per track */
u_int16_t bpbHeads; /* number of heads */
u_int32_t bpbHiddenSecs; /* # of hidden sectors */
u_int32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */
u_int32_t bpbBigFATsecs; /* like bpbFATsecs for FAT32 */
u_int16_t bpbExtFlags; /* extended flags: */
#define FATNUM 0xf /* mask for numbering active FAT */
#define FATMIRROR 0x80 /* FAT is mirrored (like it always was) */
u_int16_t bpbFSVers; /* filesystem version */
#define FSVERS 0 /* currently only 0 is understood */
u_int32_t bpbRootClust; /* start cluster for root directory */
u_int16_t bpbFSInfo; /* filesystem info structure sector */
u_int16_t bpbBackup; /* backup boot sector */
/* There is a 12 byte filler here, but we ignore it */
};
/*
* 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>
#define getushort(x) le16dec(x)
#define getulong(x) le32dec(x)
#define putushort(p, v) le16enc(p, v)
#define putulong(p, v) le32enc(p, v)
/*
* 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 {
u_int8_t bpbBytesPerSec[2]; /* bytes per sector */
u_int8_t bpbSecPerClust; /* sectors per cluster */
u_int8_t bpbResSectors[2]; /* number of reserved sectors */
u_int8_t bpbFATs; /* number of FATs */
u_int8_t bpbRootDirEnts[2]; /* number of root directory entries */
u_int8_t bpbSectors[2]; /* total number of sectors */
u_int8_t bpbMedia; /* media descriptor */
u_int8_t bpbFATsecs[2]; /* number of sectors per FAT */
u_int8_t bpbSecPerTrack[2]; /* sectors per track */
u_int8_t bpbHeads[2]; /* number of heads */
u_int8_t bpbHiddenSecs[4]; /* # of hidden sectors */
u_int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */
u_int8_t bpbBigFATsecs[4]; /* like bpbFATsecs for FAT32 */
u_int8_t bpbExtFlags[2]; /* extended flags: */
u_int8_t bpbFSVers[2]; /* filesystem version */
u_int8_t bpbRootClust[4]; /* start cluster for root directory */
u_int8_t bpbFSInfo[2]; /* filesystem info structure sector */
u_int8_t bpbBackup[2]; /* backup boot sector */
/* There is a 12 byte filler here, but we ignore it */
};
/*
* FAT32 FSInfo block.
*/
struct fsinfo {
u_int8_t fsisig1[4];
u_int8_t fsifill1[480];
u_int8_t fsisig2[4];
u_int8_t fsinfree[4];
u_int8_t fsinxtfree[4];
u_int8_t fsifill2[12];
u_int8_t fsisig3[4];
u_int8_t fsifill3[508];
u_int8_t fsisig4[4];
};