Source to i386/include/param.h
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)param.h 8.1 (Berkeley) 6/11/93
*/
/*
* Machine dependent constants for Intel 386.
*/
#define MACHINE "i386"
/*
* Round p (pointer or byte index) up to a correctly-aligned value for all
* data types (int, long, ...). The result is u_int and must be cast to
* any desired pointer type.
*/
#define ALIGNBYTES 3
#define ALIGN(p) (((u_int)(p) + ALIGNBYTES) &~ ALIGNBYTES)
#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
/* NOTE: SSIZE, SINCR and UPAGES must be multiples of CLSIZE */
#define SSIZE 1 /* initial stack size/NBPG */
#define SINCR 1 /* increment of stack/NBPG */
#define UPAGES 2 /* pages of u-area */
/*
* Constants related to network buffer management.
* MCLBYTES must be no larger than CLBYTES (the software page size), and,
* on machines that exchange pages of input or output buffers with mbuf
* clusters (MAPPED_MBUFS), MCLBYTES must also be an integral multiple
* of the hardware page size.
*/
#define MSIZE 128 /* size of an mbuf */
#define MCLBYTES 1024
#define MCLSHIFT 10
#define MCLOFSET (MCLBYTES - 1)
#ifndef NMBCLUSTERS
#ifdef GATEWAY
#define NMBCLUSTERS 512 /* map size, max cluster allocation */
#else
#define NMBCLUSTERS 256 /* map size, max cluster allocation */
#endif
#endif
/*
* Size of kernel malloc arena in CLBYTES-sized logical pages
*/
#ifndef NKMEMCLUSTERS
#define NKMEMCLUSTERS (2048*1024/CLBYTES)
#endif
/*
* 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))
/*
* Mach derived conversion macros
*/
#define i386_round_pdr(x) ((((unsigned)(x)) + NBPDR - 1) & ~(NBPDR-1))
#define i386_trunc_pdr(x) ((unsigned)(x) & ~(NBPDR-1))
#define i386_round_page(x) ((((unsigned)(x)) + NBPG - 1) & ~(NBPG-1))
#define i386_trunc_page(x) ((unsigned)(x) & ~(NBPG-1))
#define i386_btod(x) ((unsigned)(x) >> PDRSHIFT)
#define i386_dtob(x) ((unsigned)(x) << PDRSHIFT)
#define i386_btop(x) ((unsigned)(x) >> PGSHIFT)
#define i386_ptob(x) ((unsigned)(x) << PGSHIFT)
#ifndef KERNEL
/* DELAY is in locore.s for the kernel */
#define DELAY(n) { register int N = (n); while (--N > 0); }
#endif