usr/src/sys/sys/dkbad.h

/*      dkbad.h 4.3     81/05/10        */

/*
 * Definitions needed to perform bad sector
 * revectoring ala DEC STD 144.
 *
 * The bad sector information is located in the
 * first 5 even numbered sectors of the last
 * track of the disk pack.  There are five
 * identical copies of the information, described
 * by the dkbad structure.
 *
 * Replacement sectors are allocated starting with
 * the first sector before the bad sector information
 * and working backwards towards the beginning of
 * the disk.  A maximum of 126 bad sectors are supported.
 * The position of the bad sector in the bad sector table
 * determines which replacement sector it corresponds to.
 *
 * The bad sector information and replacement sectors
 * are conventionally only accessible through the
 * 'c' file system partition of the disk.  If that
 * partition is used for a file system, the user is
 * responsible for making sure that it does not overlap
 * the bad sector information or any replacement sector.s
 */

struct dkbad {
        long    bt_csn;                 /* cartridge serial number */
        u_short bt_mbz;                 /* unused; should be 0 */
        u_short bt_flag;                /* -1 => alignment cartridge */
        struct bt_bad {
                u_short bt_cyl;         /* cylinder number of bad sector */
                u_short bt_trksec;      /* track and sector number */
        } bt_bad[126];
};

#define ECC     0
#define SSE     1
#define BSE     2
#define CONT    3