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 */ 26struct 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 38struct 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 48struct 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 60struct 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 78struct 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 88union 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