2.11BSD/sys/h/dkbad.h

/*
 * Copyright (c) 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)dkbad.h	1.1 (2.10BSD Berkeley) 12/1/86
 */

/*
 * 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
 */

/*
 * The 2.10BSD system defines MAXBAD as 32, not 126, although there
 * should be no problem with increasing that value.  It's your basic
 * space tradeoff.  Also, 2.10 drivers tend to have the bad sector
 * information available through the 'h' file system partition, although
 * there are exceptions to this rule.  Note, this value is also present
 * in the bad144 program.
 */
#define MAXBAD	32			/* Maximum bad sectors supported */

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[MAXBAD];
};

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