sys/i386/include/pc/msdos.h

/*
 * msdos common header file
 * [obtained from mtools -wfj]
 * how to decipher DOS disk structures in coexisting with DOS
 *
 *      $Id$
 */

#define MSECTOR_SIZE    512             /* MSDOS sector size in bytes */
#define MDIR_SIZE       32              /* MSDOS directory size in bytes */
#define MAX_CLUSTER     8192            /* largest cluster size */
#define MAX_PATH        128             /* largest MSDOS path length */
#define MAX_DIR_SECS    64              /* largest directory (in sectors) */

#define NEW             1
#define OLD             0

struct directory {
        unsigned char name[8];          /* file name */
        unsigned char ext[3];           /* file extension */
        unsigned char attr;             /* attribute byte */
        unsigned char reserved[10];     /* ?? */
        unsigned char time[2];          /* time stamp */
        unsigned char date[2];          /* date stamp */
        unsigned char start[2];         /* starting cluster number */
        unsigned char size[4];          /* size of the file */
};

struct bootsector {
        unsigned char jump[3];          /* Jump to boot code */
        unsigned char banner[8];        /* OEM name & version */
        unsigned char secsiz[2];        /* Bytes per sector hopefully 512 */
        unsigned char clsiz;            /* Cluster size in sectors */
        unsigned char nrsvsect[2];      /* Number of reserved (boot) sectors */
        unsigned char nfat;             /* Number of FAT tables hopefully 2 */
        unsigned char dirents[2];       /* Number of directory slots */
        unsigned char psect[2];         /* Total sectors on disk */
        unsigned char descr;            /* Media descriptor=first byte of FAT */
        unsigned char fatlen[2];        /* Sectors in FAT */
        unsigned char nsect[2];         /* Sectors/track */
        unsigned char nheads[2];        /* Heads */
        unsigned char nhs[4];           /* number of hidden sectors */
        unsigned char bigsect[4];       /* big total sectors */
        unsigned char junk[476];        /* who cares? */
};

/* DOS partition table -- located in boot block */

#define DOSBBSECTOR     0       /* DOS boot block relative sector number */
#define DOSPARTOFF      446
#define NDOSPART        4

struct dos_partition {
        unsigned char   dp_flag;        /* bootstrap flags */
        unsigned char   dp_shd;         /* starting head */
        unsigned char   dp_ssect;       /* starting sector */
        unsigned char   dp_scyl;        /* starting cylinder */
        unsigned char   dp_typ;         /* partition type */
#define         DOSPTYP_386BSD  0xa5            /* 386BSD partition type */
        unsigned char   dp_ehd;         /* end head */
        unsigned char   dp_esect;       /* end sector */
        unsigned char   dp_ecyl;        /* end cylinder */
        unsigned long   dp_start;       /* absolute starting sector number */
        unsigned long   dp_size;        /* partition size in sectors */
} dos_partitions[NDOSPART];