minix/sys/ufs/mfs/mfs_miniroot.c

/*	$NetBSD: mfs_miniroot.c,v 1.1 2010/03/02 17:20:02 pooka Exp $	*/

/*
 * Copyright (c) 1989, 1990, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * 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. 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.
 *
 *	@(#)mfs_vfsops.c	8.11 (Berkeley) 6/19/95
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: mfs_miniroot.c,v 1.1 2010/03/02 17:20:02 pooka Exp $");

#include <sys/param.h>

#include <ufs/mfs/mfs_extern.h>
#include <ufs/ffs/fs.h>

void *	mfs_rootbase;	/* address of mini-root in kernel virtual memory */
u_long	mfs_rootsize;	/* size of mini-root in bytes */

/*
 * This is called early in boot to set the base address and size
 * of the mini-root.
 */
int
mfs_initminiroot(void *base)
{
	struct fs *fs = (struct fs *)((char *)base + SBLOCK_UFS1);
	static bool inited = false;

	if (inited)
		panic("mfs_initminiroot() called more than once");
	inited = true;

	/* check for valid super block */
	if (fs->fs_magic != FS_UFS1_MAGIC || fs->fs_bsize > MAXBSIZE ||
	    fs->fs_bsize < sizeof(struct fs))
		return (0);
	rootfstype = MOUNT_MFS;
	mfs_rootbase = base;
	mfs_rootsize = fs->fs_fsize * fs->fs_size;
	rootdev = makedev(255, 0);
	return (mfs_rootsize);
}