sys/fs/msdosfs/bootsect.h

   1 /*      $NetBSD: bootsect.h,v 1.3 2005/12/03 17:34:43 christos 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 fist 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         u_int8_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         u_int8_t        bsBootSectSig0;
  33         u_int8_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         u_int8_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         u_int8_t        bsBootSectSig0;
  55         u_int8_t        bsBootSectSig1;
  56 #define BOOTSIG0        0x55
  57 #define BOOTSIG1        0xaa
  58 };
  59
  60 struct bootsector710 {
  61         u_int8_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         u_int8_t        bsBootSectSig0;
  67         u_int8_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         u_int8_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_ */