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Diffstat (limited to 'sys/msdosfs/bpb.h')
-rw-r--r-- | sys/msdosfs/bpb.h | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/sys/msdosfs/bpb.h b/sys/msdosfs/bpb.h new file mode 100644 index 0000000..70e4de2 --- /dev/null +++ b/sys/msdosfs/bpb.h @@ -0,0 +1,120 @@ +/* $Id$ */ +/* $NetBSD: bpb.h,v 1.3 1994/06/29 06:35:29 cgd 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_short bpbBytesPerSec; /* bytes per sector */ + u_char bpbSecPerClust; /* sectors per cluster */ + u_short bpbResSectors; /* number of reserved sectors */ + u_char bpbFATs; /* number of FATs */ + u_short bpbRootDirEnts; /* number of root directory entries */ + u_short bpbSectors; /* total number of sectors */ + u_char bpbMedia; /* media descriptor */ + u_short bpbFATsecs; /* number of sectors per FAT */ + u_short bpbSecPerTrack; /* sectors per track */ + u_short bpbHeads; /* number of heads */ + u_short 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_short bpbBytesPerSec; /* bytes per sector */ + u_char bpbSecPerClust; /* sectors per cluster */ + u_short bpbResSectors; /* number of reserved sectors */ + u_char bpbFATs; /* number of FATs */ + u_short bpbRootDirEnts; /* number of root directory entries */ + u_short bpbSectors; /* total number of sectors */ + u_char bpbMedia; /* media descriptor */ + u_short bpbFATsecs; /* number of sectors per FAT */ + u_short bpbSecPerTrack; /* sectors per track */ + u_short bpbHeads; /* number of heads */ + u_long bpbHiddenSecs; /* number of hidden sectors */ + u_long bpbHugeSectors; /* number of sectrs if bpbSectors == 0 */ +}; + +/* + * 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 <machine/endian.h> +#if BYTE_ORDER == LITTLE_ENDIAN /* && can do unaligned accesses */ +#define getushort(x) *((u_short *)(x)) +#define getulong(x) *((u_long *)(x)) +#define putushort(p, v) (*((u_short *)(p)) = (v)) +#define putulong(p, v) (*((u_long *)(p)) = (v)) + +#else +#define getushort(x) (((u_char *)(x))[0] + (((u_char *)(x))[1] << 8)) +#define getulong(x) (((u_char *)(x))[0] + (((u_char *)(x))[1] << 8) \ + + (((u_char *)(x))[2] << 16) \ + + (((u_char *)(x))[3] << 24)) +#define putushort(p, v) (((u_char *)(p))[0] = (v), \ + ((u_char *)(p))[1] = (v) >> 8) +#define putulong(p, v) (((u_char *)(p))[0] = (v), \ + ((u_char *)(p))[1] = (v) >> 8, \ + ((u_char *)(p))[2] = (v) >> 16,\ + ((u_char *)(p))[3] = (v) >> 24) +#endif + +/* + * BIOS Parameter Block (BPB) for DOS 3.3 + */ +struct byte_bpb33 { + char bpbBytesPerSec[2]; /* bytes per sector */ + char bpbSecPerClust; /* sectors per cluster */ + char bpbResSectors[2]; /* number of reserved sectors */ + char bpbFATs; /* number of FATs */ + char bpbRootDirEnts[2]; /* number of root directory entries */ + char bpbSectors[2]; /* total number of sectors */ + char bpbMedia; /* media descriptor */ + char bpbFATsecs[2]; /* number of sectors per FAT */ + char bpbSecPerTrack[2]; /* sectors per track */ + char bpbHeads[2]; /* number of heads */ + char 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 { + char bpbBytesPerSec[2]; /* bytes per sector */ + char bpbSecPerClust; /* sectors per cluster */ + char bpbResSectors[2]; /* number of reserved sectors */ + char bpbFATs; /* number of FATs */ + char bpbRootDirEnts[2]; /* number of root directory entries */ + char bpbSectors[2]; /* total number of sectors */ + char bpbMedia; /* media descriptor */ + char bpbFATsecs[2]; /* number of sectors per FAT */ + char bpbSecPerTrack[2]; /* sectors per track */ + char bpbHeads[2]; /* number of heads */ + char bpbHiddenSecs[4]; /* number of hidden sectors */ + char bpbHugeSectors[4]; /* number of sectrs if bpbSectors == 0 */ +}; |