/*
 * Machine dependent constants for Intel 386.
 */

#define MACHINE "i386"

#ifndef BYTE_ORDER
#include <machine/endian.h>
#endif

#define	NBPG		4096		/* bytes/page */
#define	PGOFSET		(NBPG-1)	/* byte offset into page */
#define	PGSHIFT		12		/* LOG2(NBPG) */
#define	NPTEPG		(NBPG/(sizeof (struct pte)))

#define NBPDR		(1024*NBPG)	/* bytes/page dir */
#define	PDROFSET	(NBPDR-1)	/* byte offset into page dir */
#define	PDRSHIFT	22		/* LOG2(NBPDR) */

#define	KERNBASE	0xFE000000	/* start of kernel virtual */
#define	BTOPKERNBASE	((u_long)KERNBASE >> PGSHIFT)

#define	DEV_BSIZE	512
#define	DEV_BSHIFT	9		/* log2(DEV_BSIZE) */
#define BLKDEV_IOSIZE	2048
#define	MAXPHYS		(64 * 1024)	/* max raw I/O transfer size */

#define	CLSIZE		1
#define	CLSIZELOG2	0

#define	SSIZE	1		/* initial stack size/NBPG */
#define	SINCR	1		/* increment of stack/NBPG */

#define	UPAGES	3		/* pages of u-area */

/*
 * Some macros for units conversion
 */
/* Core clicks (4096 bytes) to segments and vice versa */
#define	ctos(x)	(x)
#define	stoc(x)	(x)

/* Core clicks (4096 bytes) to disk blocks */
#define	ctod(x)	((x)<<(PGSHIFT-DEV_BSHIFT))
#define	dtoc(x)	((x)>>(PGSHIFT-DEV_BSHIFT))
#define	dtob(x)	((x)<<DEV_BSHIFT)

/* clicks to bytes */
#define	ctob(x)	((x)<<PGSHIFT)

/* bytes to clicks */
#define	btoc(x)	(((unsigned)(x)+(NBPG-1))>>PGSHIFT)

#define	btodb(bytes)	 		/* calculates (bytes / DEV_BSIZE) */ \
	((unsigned)(bytes) >> DEV_BSHIFT)
#define	dbtob(db)			/* calculates (db * DEV_BSIZE) */ \
	((unsigned)(db) << DEV_BSHIFT)

/*
 * Map a ``block device block'' to a file system block.
 * This should be device dependent, and will be if we
 * add an entry to cdevsw/bdevsw for that purpose.
 * For now though just use DEV_BSIZE.
 */
#define	bdbtofsb(bn)	((bn) / (BLKDEV_IOSIZE/DEV_BSIZE))

#ifdef KERNEL
#ifndef LOCORE
int	cpuspeed;
#endif
#define	DELAY(n)	{ register int N = cpuspeed * (n); while (--N > 0); }

#else KERNEL
#define	DELAY(n)	{ register int N = (n); while (--N > 0); }
#endif KERNEL