1 /* $NetBSD: bootsect.h,v 1.7 2021/08/09 21:38:05 andvar Exp $ */ 2 3 /* 4 * Written by Paul Popelka (paulp@uts.amdahl.com) 5 * 6 * You can do anything you want with this software, just don't say you wrote 7 * it, and don't remove this notice. 8 * 9 * This software is provided "as is". 10 * 11 * The author supplies this software to be publicly redistributed on the 12 * understanding that the author is not responsible for the correct 13 * functioning of this software in any circumstances and is not liable for 14 * any damages caused by this software. 15 * 16 * October 1992 17 */ 18 #ifndef _MSDOSFS_BOOTSECT_H_ 19 #define _MSDOSFS_BOOTSECT_H_ 20 21 /* 22 * Format of a boot sector. This is the first sector on a DOS floppy disk 23 * or the first sector of a partition on a hard disk. But, it is not the 24 * first sector of a partitioned hard disk. 25 */ 26 struct bootsector33 { 27 uint8_t bsJump[3]; /* jump inst E9xxxx or EBxx90 */ 28 int8_t bsOemName[8]; /* OEM name and version */ 29 int8_t bsBPB[19]; /* BIOS parameter block */ 30 int8_t bsDriveNumber; /* drive number (0x80) */ 31 int8_t bsBootCode[479]; /* pad so struct is 512b */ 32 uint8_t bsBootSectSig0; 33 uint8_t bsBootSectSig1; 34 #define BOOTSIG0 0x55 35 #define BOOTSIG1 0xaa 36 }; 37 38 struct extboot { 39 int8_t exDriveNumber; /* drive number (0x80) */ 40 int8_t exReserved1; /* reserved */ 41 int8_t exBootSignature; /* ext. boot signature (0x29) */ 42 #define EXBOOTSIG 0x29 43 int8_t exVolumeID[4]; /* volume ID number */ 44 int8_t exVolumeLabel[11]; /* volume label */ 45 int8_t exFileSysType[8]; /* fs type (FAT12 or FAT16) */ 46 }; 47 48 struct bootsector50 { 49 uint8_t bsJump[3]; /* jump inst E9xxxx or EBxx90 */ 50 int8_t bsOemName[8]; /* OEM name and version */ 51 int8_t bsBPB[25]; /* BIOS parameter block */ 52 int8_t bsExt[26]; /* Bootsector Extension */ 53 int8_t bsBootCode[448]; /* pad so structure is 512b */ 54 uint8_t bsBootSectSig0; 55 uint8_t bsBootSectSig1; 56 #define BOOTSIG0 0x55 57 #define BOOTSIG1 0xaa 58 }; 59 60 struct bootsector710 { 61 uint8_t bsJump[3]; /* jump inst E9xxxx or EBxx90 */ 62 int8_t bsOEMName[8]; /* OEM name and version */ 63 int8_t bsBPB[53]; /* BIOS parameter block */ 64 int8_t bsExt[26]; /* Bootsector Extension */ 65 int8_t bsBootCode[420]; /* pad so structure is 512b */ 66 uint8_t bsBootSectSig0; 67 uint8_t bsBootSectSig1; 68 #define BOOTSIG0 0x55 69 #define BOOTSIG1 0xaa 70 }; 71 #ifdef atari 72 /* 73 * The boot sector on a GEMDOS FS is a little bit different from the MSDOS FS 74 * format. Currently there is no need to declare a separate structure, the 75 * bootsector33 struct will do. 76 */ 77 #if 0 78 struct bootsec_atari { 79 uint8_t bsBranch[2]; /* branch inst if auto-boot */ 80 int8_t bsFiller[6]; /* anything or nothing */ 81 int8_t bsSerial[3]; /* serial no. for mediachange */ 82 int8_t bsBPB[19]; /* BIOS parameter block */ 83 int8_t bsBootCode[482]; /* pad so struct is 512b */ 84 }; 85 #endif 86 #endif /* atari */ 87 88 union bootsector { 89 struct bootsector33 bs33; 90 struct bootsector50 bs50; 91 struct bootsector710 bs710; 92 }; 93 94 #if 0 95 /* 96 * Shorthand for fields in the bpb. 97 */ 98 #define bsBytesPerSec bsBPB.bpbBytesPerSec 99 #define bsSectPerClust bsBPB.bpbSectPerClust 100 #define bsResSectors bsBPB.bpbResSectors 101 #define bsFATS bsBPB.bpbFATS 102 #define bsRootDirEnts bsBPB.bpbRootDirEnts 103 #define bsSectors bsBPB.bpbSectors 104 #define bsMedia bsBPB.bpbMedia 105 #define bsFATsecs bsBPB.bpbFATsecs 106 #define bsSectPerTrack bsBPB.bpbSectPerTrack 107 #define bsHeads bsBPB.bpbHeads 108 #define bsHiddenSecs bsBPB.bpbHiddenSecs 109 #define bsHugeSectors bsBPB.bpbHugeSectors 110 #endif 111 112 #endif /* _MSDOSFS_BOOTSECT_H_ */ 113