1/* $OpenBSD: bpb.h,v 1.7 2015/10/23 10:45:31 krw Exp $ */ 2/* $NetBSD: bpb.h,v 1.6 1997/10/17 11:23:35 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/* 85 * The following structures represent how the bpb's look on disk. shorts 86 * and longs are just character arrays of the appropriate length. This is 87 * because the compiler forces shorts and longs to align on word or 88 * halfword boundaries. 89 * 90 * XXX The little-endian code here assumes that the processor can access 91 * 16-bit and 32-bit quantities on byte boundaries. If this is not true, 92 * use the macros for the big-endian case. 93 */ 94#include <sys/endian.h> 95#if (BYTE_ORDER == LITTLE_ENDIAN) && !defined(__STRICT_ALIGNMENT) 96#define getushort(x) *((u_int16_t *)(x)) 97#define getulong(x) *((u_int32_t *)(x)) 98#define putushort(p, v) (*((u_int16_t *)(p)) = (v)) 99#define putulong(p, v) (*((u_int32_t *)(p)) = (v)) 100#else 101#define getushort(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8)) 102#define getulong(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8) \ 103 + (((u_int8_t *)(x))[2] << 16) \ 104 + (((u_int8_t *)(x))[3] << 24)) 105#define putushort(p, v) (((u_int8_t *)(p))[0] = (v), \ 106 ((u_int8_t *)(p))[1] = (v) >> 8) 107#define putulong(p, v) (((u_int8_t *)(p))[0] = (v), \ 108 ((u_int8_t *)(p))[1] = (v) >> 8, \ 109 ((u_int8_t *)(p))[2] = (v) >> 16,\ 110 ((u_int8_t *)(p))[3] = (v) >> 24) 111#endif 112 113/* 114 * BIOS Parameter Block (BPB) for DOS 3.3 115 */ 116struct byte_bpb33 { 117 int8_t bpbBytesPerSec[2]; /* bytes per sector */ 118 int8_t bpbSecPerClust; /* sectors per cluster */ 119 int8_t bpbResSectors[2]; /* number of reserved sectors */ 120 int8_t bpbFATs; /* number of FATs */ 121 int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 122 int8_t bpbSectors[2]; /* total number of sectors */ 123 int8_t bpbMedia; /* media descriptor */ 124 int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 125 int8_t bpbSecPerTrack[2]; /* sectors per track */ 126 int8_t bpbHeads[2]; /* number of heads */ 127 int8_t bpbHiddenSecs[2]; /* number of hidden sectors */ 128}; 129 130/* 131 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3, 132 * and bpbHugeSectors is not in the 3.3 bpb. 133 */ 134struct byte_bpb50 { 135 int8_t bpbBytesPerSec[2]; /* bytes per sector */ 136 int8_t bpbSecPerClust; /* sectors per cluster */ 137 int8_t bpbResSectors[2]; /* number of reserved sectors */ 138 int8_t bpbFATs; /* number of FATs */ 139 int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 140 int8_t bpbSectors[2]; /* total number of sectors */ 141 int8_t bpbMedia; /* media descriptor */ 142 int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 143 int8_t bpbSecPerTrack[2]; /* sectors per track */ 144 int8_t bpbHeads[2]; /* number of heads */ 145 int8_t bpbHiddenSecs[4]; /* number of hidden sectors */ 146 int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */ 147}; 148 149/* 150 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50. 151 */ 152struct byte_bpb710 { 153 u_int8_t bpbBytesPerSec[2]; /* bytes per sector */ 154 u_int8_t bpbSecPerClust; /* sectors per cluster */ 155 u_int8_t bpbResSectors[2]; /* number of reserved sectors */ 156 u_int8_t bpbFATs; /* number of FATs */ 157 u_int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 158 u_int8_t bpbSectors[2]; /* total number of sectors */ 159 u_int8_t bpbMedia; /* media descriptor */ 160 u_int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 161 u_int8_t bpbSecPerTrack[2]; /* sectors per track */ 162 u_int8_t bpbHeads[2]; /* number of heads */ 163 u_int8_t bpbHiddenSecs[4]; /* # of hidden sectors */ 164 u_int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */ 165 u_int8_t bpbBigFATsecs[4]; /* like bpbFATsecs for FAT32 */ 166 u_int8_t bpbExtFlags[2]; /* extended flags: */ 167 u_int8_t bpbFSVers[2]; /* filesystem version */ 168 u_int8_t bpbRootClust[4]; /* start cluster for root directory */ 169 u_int8_t bpbFSInfo[2]; /* filesystem info structure sector */ 170 u_int8_t bpbBackup[2]; /* backup boot sector */ 171 /* There is a 12 byte filler here, but we ignore it */ 172}; 173 174/* 175 * FAT32 FSInfo block. 176 */ 177struct fsinfo { 178 u_int8_t fsisig1[4]; 179 u_int8_t fsifill1[480]; 180 u_int8_t fsisig2[4]; 181 u_int8_t fsinfree[4]; 182 u_int8_t fsinxtfree[4]; 183 u_int8_t fsifill2[12]; 184 u_int8_t fsisig3[4]; 185 u_int8_t fsifill3[508]; 186 u_int8_t fsisig4[4]; 187}; 188