src/sys/msdosfs/bootsect.h

98 lines
3.0 KiB
C

/* $OpenBSD: bootsect.h,v 1.7 2016/10/10 00:34:50 bluhm Exp $ */
/* $NetBSD: bootsect.h,v 1.8 1997/10/17 11:23:29 ws Exp $ */
/*
* Written by Paul Popelka (paulp@uts.amdahl.com)
*
* You can do anything you want with this software, just don't say you wrote
* it, and don't remove this notice.
*
* This software is provided "as is".
*
* The author supplies this software to be publicly redistributed on the
* understanding that the author is not responsible for the correct
* functioning of this software in any circumstances and is not liable for
* any damages caused by this software.
*
* October 1992
*/
/*
* Format of a boot sector. This is the first sector on a DOS floppy disk
* or the fist sector of a partition on a hard disk. But, it is not the
* first sector of a partitioned hard disk.
*/
struct bootsector33 {
u_int8_t bsJump[3]; /* jump inst E9xxxx or EBxx90 */
int8_t bsOemName[8]; /* OEM name and version */
int8_t bsBPB[19]; /* BIOS parameter block */
int8_t bsDriveNumber; /* drive number (0x80) */
int8_t bsBootCode[479]; /* pad so struct is 512b */
u_int8_t bsBootSectSig0;
u_int8_t bsBootSectSig1;
#define BOOTSIG0 0x55
#define BOOTSIG1 0xaa
};
struct extboot {
int8_t exDriveNumber; /* drive number (0x80) */
int8_t exReserved1; /* reserved */
int8_t exBootSignature; /* ext. boot signature (0x29) */
#define EXBOOTSIG 0x29
int8_t exVolumeID[4]; /* volume ID number */
int8_t exVolumeLabel[11]; /* volume label */
int8_t exFileSysType[8]; /* fs type (FAT12 or FAT16) */
};
struct bootsector50 {
u_int8_t bsJump[3]; /* jump inst E9xxxx or EBxx90 */
int8_t bsOemName[8]; /* OEM name and version */
int8_t bsBPB[25]; /* BIOS parameter block */
int8_t bsExt[26]; /* Bootsector Extension */
int8_t bsBootCode[448]; /* pad so structure is 512b */
u_int8_t bsBootSectSig0;
u_int8_t bsBootSectSig1;
#define BOOTSIG0 0x55
#define BOOTSIG1 0xaa
};
struct bootsector710 {
u_int8_t bsJump[3]; /* jump inst E9xxxx or EBxx90 */
int8_t bsOEMName[8]; /* OEM name and version */
int8_t bsBPB[53]; /* BIOS parameter block */
int8_t bsExt[26]; /* Bootsector Extension */
int8_t bsBootCode[418]; /* pad so structure is 512b */
u_int8_t bsBootSectSig2; /* 2 & 3 are only defined for FAT32? */
u_int8_t bsBootSectSig3;
u_int8_t bsBootSectSig0;
u_int8_t bsBootSectSig1;
#define BOOTSIG0 0x55
#define BOOTSIG1 0xaa
#define BOOTSIG2 0
#define BOOTSIG3 0
};
union bootsector {
struct bootsector33 bs33;
struct bootsector50 bs50;
struct bootsector710 bs710;
};
#if 0
/*
* Shorthand for fields in the bpb.
*/
#define bsBytesPerSec bsBPB.bpbBytesPerSec
#define bsSectPerClust bsBPB.bpbSectPerClust
#define bsResSectors bsBPB.bpbResSectors
#define bsFATS bsBPB.bpbFATS
#define bsRootDirEnts bsBPB.bpbRootDirEnts
#define bsSectors bsBPB.bpbSectors
#define bsMedia bsBPB.bpbMedia
#define bsFATsecs bsBPB.bpbFATsecs
#define bsSectPerTrack bsBPB.bpbSectPerTrack
#define bsHeads bsBPB.bpbHeads
#define bsHiddenSecs bsBPB.bpbHiddenSecs
#define bsHugeSectors bsBPB.bpbHugeSectors
#endif