bpb.h revision 33548
1/* $Id: bpb.h,v 1.5 1997/02/22 09:40:44 peter Exp $ */ 2/* $NetBSD: bpb.h,v 1.7 1997/11/17 15:36:24 ws Exp $ */ 3 4/* 5 * Written by Paul Popelka (paulp@uts.amdahl.com) 6 * 7 * You can do anything you want with this software, just don't say you wrote 8 * it, and don't remove this notice. 9 * 10 * This software is provided "as is". 11 * 12 * The author supplies this software to be publicly redistributed on the 13 * understanding that the author is not responsible for the correct 14 * functioning of this software in any circumstances and is not liable for 15 * any damages caused by this software. 16 * 17 * October 1992 18 */ 19 20/* 21 * BIOS Parameter Block (BPB) for DOS 3.3 22 */ 23struct bpb33 { 24 u_int16_t bpbBytesPerSec; /* bytes per sector */ 25 u_int8_t bpbSecPerClust; /* sectors per cluster */ 26 u_int16_t bpbResSectors; /* number of reserved sectors */ 27 u_int8_t bpbFATs; /* number of FATs */ 28 u_int16_t bpbRootDirEnts; /* number of root directory entries */ 29 u_int16_t bpbSectors; /* total number of sectors */ 30 u_int8_t bpbMedia; /* media descriptor */ 31 u_int16_t bpbFATsecs; /* number of sectors per FAT */ 32 u_int16_t bpbSecPerTrack; /* sectors per track */ 33 u_int16_t bpbHeads; /* number of heads */ 34 u_int16_t bpbHiddenSecs; /* number of hidden sectors */ 35}; 36 37/* 38 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3, 39 * and bpbHugeSectors is not in the 3.3 bpb. 40 */ 41struct bpb50 { 42 u_int16_t bpbBytesPerSec; /* bytes per sector */ 43 u_int8_t bpbSecPerClust; /* sectors per cluster */ 44 u_int16_t bpbResSectors; /* number of reserved sectors */ 45 u_int8_t bpbFATs; /* number of FATs */ 46 u_int16_t bpbRootDirEnts; /* number of root directory entries */ 47 u_int16_t bpbSectors; /* total number of sectors */ 48 u_int8_t bpbMedia; /* media descriptor */ 49 u_int16_t bpbFATsecs; /* number of sectors per FAT */ 50 u_int16_t bpbSecPerTrack; /* sectors per track */ 51 u_int16_t bpbHeads; /* number of heads */ 52 u_int32_t bpbHiddenSecs; /* # of hidden sectors */ 53 u_int32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */ 54}; 55 56/* 57 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50. 58 */ 59struct bpb710 { 60 u_int16_t bpbBytesPerSec; /* bytes per sector */ 61 u_int8_t bpbSecPerClust; /* sectors per cluster */ 62 u_int16_t bpbResSectors; /* number of reserved sectors */ 63 u_int8_t bpbFATs; /* number of FATs */ 64 u_int16_t bpbRootDirEnts; /* number of root directory entries */ 65 u_int16_t bpbSectors; /* total number of sectors */ 66 u_int8_t bpbMedia; /* media descriptor */ 67 u_int16_t bpbFATsecs; /* number of sectors per FAT */ 68 u_int16_t bpbSecPerTrack; /* sectors per track */ 69 u_int16_t bpbHeads; /* number of heads */ 70 u_int32_t bpbHiddenSecs; /* # of hidden sectors */ 71 u_int32_t bpbHugeSectors; /* # of sectors if bpbSectors == 0 */ 72 u_int32_t bpbBigFATsecs; /* like bpbFATsecs for FAT32 */ 73 u_int16_t bpbExtFlags; /* extended flags: */ 74#define FATNUM 0xf /* mask for numbering active FAT */ 75#define FATMIRROR 0x80 /* FAT is mirrored (like it always was) */ 76 u_int16_t bpbFSVers; /* filesystem version */ 77#define FSVERS 0 /* currently only 0 is understood */ 78 u_int32_t bpbRootClust; /* start cluster for root directory */ 79 u_int16_t bpbFSInfo; /* filesystem info structure sector */ 80 u_int16_t bpbBackup; /* backup boot sector */ 81 /* There is a 12 byte filler here, but we ignore it */ 82}; 83 84#ifdef atari 85/* 86 * BPB for gemdos filesystems. Atari leaves the obsolete stuff undefined. 87 * Currently there is no need for a separate BPB structure. 88 */ 89#if 0 90struct bpb_a { 91 u_int16_t bpbBytesPerSec; /* bytes per sector */ 92 u_int8_t bpbSecPerClust; /* sectors per cluster */ 93 u_int16_t bpbResSectors; /* number of reserved sectors */ 94 u_int8_t bpbFATs; /* number of FATs */ 95 u_int16_t bpbRootDirEnts; /* number of root directory entries */ 96 u_int16_t bpbSectors; /* total number of sectors */ 97 u_int8_t bpbUseless1; /* meaningless on gemdos fs */ 98 u_int16_t bpbFATsecs; /* number of sectors per FAT */ 99 u_int16_t bpbUseless2; /* meaningless for harddisk fs */ 100 u_int16_t bpbUseless3; /* meaningless for harddisk fs */ 101 u_int16_t bpbHiddenSecs; /* the TOS-BIOS ignores this */ 102}; 103#endif 104#endif /* atari */ 105 106/* 107 * The following structures represent how the bpb's look on disk. shorts 108 * and longs are just character arrays of the appropriate length. This is 109 * because the compiler forces shorts and longs to align on word or 110 * halfword boundaries. 111 * 112 * XXX The little-endian code here assumes that the processor can access 113 * 16-bit and 32-bit quantities on byte boundaries. If this is not true, 114 * use the macros for the big-endian case. 115 */ 116#include <machine/endian.h> 117#if (BYTE_ORDER == LITTLE_ENDIAN) /* && defined(UNALIGNED_ACCESS) */ 118#define getushort(x) *((u_int16_t *)(x)) 119#define getulong(x) *((u_int32_t *)(x)) 120#define putushort(p, v) (*((u_int16_t *)(p)) = (v)) 121#define putulong(p, v) (*((u_int32_t *)(p)) = (v)) 122#else 123#define getushort(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8)) 124#define getulong(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8) \ 125 + (((u_int8_t *)(x))[2] << 16) \ 126 + (((u_int8_t *)(x))[3] << 24)) 127#define putushort(p, v) (((u_int8_t *)(p))[0] = (v), \ 128 ((u_int8_t *)(p))[1] = (v) >> 8) 129#define putulong(p, v) (((u_int8_t *)(p))[0] = (v), \ 130 ((u_int8_t *)(p))[1] = (v) >> 8, \ 131 ((u_int8_t *)(p))[2] = (v) >> 16,\ 132 ((u_int8_t *)(p))[3] = (v) >> 24) 133#endif 134 135/* 136 * BIOS Parameter Block (BPB) for DOS 3.3 137 */ 138struct byte_bpb33 { 139 int8_t bpbBytesPerSec[2]; /* bytes per sector */ 140 int8_t bpbSecPerClust; /* sectors per cluster */ 141 int8_t bpbResSectors[2]; /* number of reserved sectors */ 142 int8_t bpbFATs; /* number of FATs */ 143 int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 144 int8_t bpbSectors[2]; /* total number of sectors */ 145 int8_t bpbMedia; /* media descriptor */ 146 int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 147 int8_t bpbSecPerTrack[2]; /* sectors per track */ 148 int8_t bpbHeads[2]; /* number of heads */ 149 int8_t bpbHiddenSecs[2]; /* number of hidden sectors */ 150}; 151 152/* 153 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3, 154 * and bpbHugeSectors is not in the 3.3 bpb. 155 */ 156struct byte_bpb50 { 157 int8_t bpbBytesPerSec[2]; /* bytes per sector */ 158 int8_t bpbSecPerClust; /* sectors per cluster */ 159 int8_t bpbResSectors[2]; /* number of reserved sectors */ 160 int8_t bpbFATs; /* number of FATs */ 161 int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 162 int8_t bpbSectors[2]; /* total number of sectors */ 163 int8_t bpbMedia; /* media descriptor */ 164 int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 165 int8_t bpbSecPerTrack[2]; /* sectors per track */ 166 int8_t bpbHeads[2]; /* number of heads */ 167 int8_t bpbHiddenSecs[4]; /* number of hidden sectors */ 168 int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */ 169}; 170 171/* 172 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50. 173 */ 174struct byte_bpb710 { 175 u_int8_t bpbBytesPerSec[2]; /* bytes per sector */ 176 u_int8_t bpbSecPerClust; /* sectors per cluster */ 177 u_int8_t bpbResSectors[2]; /* number of reserved sectors */ 178 u_int8_t bpbFATs; /* number of FATs */ 179 u_int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 180 u_int8_t bpbSectors[2]; /* total number of sectors */ 181 u_int8_t bpbMedia; /* media descriptor */ 182 u_int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 183 u_int8_t bpbSecPerTrack[2]; /* sectors per track */ 184 u_int8_t bpbHeads[2]; /* number of heads */ 185 u_int8_t bpbHiddenSecs[4]; /* # of hidden sectors */ 186 u_int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */ 187 u_int8_t bpbBigFATsecs[4]; /* like bpbFATsecs for FAT32 */ 188 u_int8_t bpbExtFlags[2]; /* extended flags: */ 189 u_int8_t bpbFSVers[2]; /* filesystem version */ 190 u_int8_t bpbRootClust[4]; /* start cluster for root directory */ 191 u_int8_t bpbFSInfo[2]; /* filesystem info structure sector */ 192 u_int8_t bpbBackup[2]; /* backup boot sector */ 193 /* There is a 12 byte filler here, but we ignore it */ 194}; 195 196/* 197 * FAT32 FSInfo block. 198 */ 199struct fsinfo { 200 u_int8_t fsisig1[4]; 201 u_int8_t fsifill1[480]; 202 u_int8_t fsisig2[4]; 203 u_int8_t fsinfree[4]; 204 u_int8_t fsinxtfree[4]; 205 u_int8_t fsifill2[12]; 206 u_int8_t fsisig3[4]; 207 u_int8_t fsifill3[508]; 208 u_int8_t fsisig4[4]; 209}; 210