1 /* $FreeBSD$ */ 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 */ 23 struct 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 */ 41 struct 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 */ 59 struct 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 95 #include <machine/endian.h> 96 97 #ifdef __i386__ 98 #define UNLALIGNED_ACCESS 99 #endif 100 101 #if (BYTE_ORDER == LITTLE_ENDIAN) && defined(UNALIGNED_ACCESS) 102 #define getushort(x) *((u_int16_t *)(x)) 103 #define getulong(x) *((u_int32_t *)(x)) 104 #define putushort(p, v) (*((u_int16_t *)(p)) = (v)) 105 #define putulong(p, v) (*((u_int32_t *)(p)) = (v)) 106 #else 107 #define getushort(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8)) 108 #define getulong(x) (((u_int8_t *)(x))[0] + (((u_int8_t *)(x))[1] << 8) \ 109 + (((u_int8_t *)(x))[2] << 16) \ 110 + (((u_int8_t *)(x))[3] << 24)) 111 #define putushort(p, v) (((u_int8_t *)(p))[0] = (v), \ 112 ((u_int8_t *)(p))[1] = (v) >> 8) 113 #define putulong(p, v) (((u_int8_t *)(p))[0] = (v), \ 114 ((u_int8_t *)(p))[1] = (v) >> 8, \ 115 ((u_int8_t *)(p))[2] = (v) >> 16,\ 116 ((u_int8_t *)(p))[3] = (v) >> 24) 117 #endif 118 119 /* 120 * BIOS Parameter Block (BPB) for DOS 3.3 121 */ 122 struct byte_bpb33 { 123 int8_t bpbBytesPerSec[2]; /* bytes per sector */ 124 int8_t bpbSecPerClust; /* sectors per cluster */ 125 int8_t bpbResSectors[2]; /* number of reserved sectors */ 126 int8_t bpbFATs; /* number of FATs */ 127 int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 128 int8_t bpbSectors[2]; /* total number of sectors */ 129 int8_t bpbMedia; /* media descriptor */ 130 int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 131 int8_t bpbSecPerTrack[2]; /* sectors per track */ 132 int8_t bpbHeads[2]; /* number of heads */ 133 int8_t bpbHiddenSecs[2]; /* number of hidden sectors */ 134 }; 135 136 /* 137 * BPB for DOS 5.0 The difference is bpbHiddenSecs is a short for DOS 3.3, 138 * and bpbHugeSectors is not in the 3.3 bpb. 139 */ 140 struct byte_bpb50 { 141 int8_t bpbBytesPerSec[2]; /* bytes per sector */ 142 int8_t bpbSecPerClust; /* sectors per cluster */ 143 int8_t bpbResSectors[2]; /* number of reserved sectors */ 144 int8_t bpbFATs; /* number of FATs */ 145 int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 146 int8_t bpbSectors[2]; /* total number of sectors */ 147 int8_t bpbMedia; /* media descriptor */ 148 int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 149 int8_t bpbSecPerTrack[2]; /* sectors per track */ 150 int8_t bpbHeads[2]; /* number of heads */ 151 int8_t bpbHiddenSecs[4]; /* number of hidden sectors */ 152 int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */ 153 }; 154 155 /* 156 * BPB for DOS 7.10 (FAT32). This one has a few extensions to bpb50. 157 */ 158 struct byte_bpb710 { 159 u_int8_t bpbBytesPerSec[2]; /* bytes per sector */ 160 u_int8_t bpbSecPerClust; /* sectors per cluster */ 161 u_int8_t bpbResSectors[2]; /* number of reserved sectors */ 162 u_int8_t bpbFATs; /* number of FATs */ 163 u_int8_t bpbRootDirEnts[2]; /* number of root directory entries */ 164 u_int8_t bpbSectors[2]; /* total number of sectors */ 165 u_int8_t bpbMedia; /* media descriptor */ 166 u_int8_t bpbFATsecs[2]; /* number of sectors per FAT */ 167 u_int8_t bpbSecPerTrack[2]; /* sectors per track */ 168 u_int8_t bpbHeads[2]; /* number of heads */ 169 u_int8_t bpbHiddenSecs[4]; /* # of hidden sectors */ 170 u_int8_t bpbHugeSectors[4]; /* # of sectors if bpbSectors == 0 */ 171 u_int8_t bpbBigFATsecs[4]; /* like bpbFATsecs for FAT32 */ 172 u_int8_t bpbExtFlags[2]; /* extended flags: */ 173 u_int8_t bpbFSVers[2]; /* filesystem version */ 174 u_int8_t bpbRootClust[4]; /* start cluster for root directory */ 175 u_int8_t bpbFSInfo[2]; /* filesystem info structure sector */ 176 u_int8_t bpbBackup[2]; /* backup boot sector */ 177 /* There is a 12 byte filler here, but we ignore it */ 178 }; 179 180 /* 181 * FAT32 FSInfo block. 182 */ 183 struct fsinfo { 184 u_int8_t fsisig1[4]; 185 u_int8_t fsifill1[480]; 186 u_int8_t fsisig2[4]; 187 u_int8_t fsinfree[4]; 188 u_int8_t fsinxtfree[4]; 189 u_int8_t fsifill2[12]; 190 u_int8_t fsisig3[4]; 191 u_int8_t fsifill3[508]; 192 u_int8_t fsisig4[4]; 193 }; 194