#!/bin/sh

## Lars Kellogg-Stedman <lars@larsshack.org>
## $Id: linuxrc,v 1.6 2001/11/28 21:05:25 lars Exp lars $
##
## This is the linuxrc script I use to boot up my root-on-LVM
## system.  If you pass the 'rescue' parameter on the kernel 
## command line, you will get a shell prompt before continuing
## with the normal (post-initrd) boot process.

ROOTDEV=/dev/vg00/root

MODDIR=/lib/modules
MODULES="scsi_mod sd_mod aic7xxx md xor raid5 lvm-mod"

RCSID='$Id: linuxrc,v 1.6 2001/11/28 21:05:25 lars Exp lars $'
PATH=/bin:/sbin; export PATH

STARTSHELL=0

## We need to mount /proc before running busybox --install.
busybox mount -t proc none /proc

busybox echo "** Setting up busybox links..."
busybox --install -s || {
	echo "## BUSYBOX install failed!" >&2
	exec /bin/sh
}

cat <<EOF

**********************************************************************
** Root on LVM
** Lars Kellogg-Stedman <lars@larsshack.org>
** $RCSID
**

EOF

## check for the 'rescue' parameter on the kernel command line.
grep rescue /proc/cmdline > /dev/null 2>&1 && STARTSHELL=1

echo "** Loading modules..."
for m in $MODULES; do
	echo "  $m module..."
	insmod ${MODDIR}/${m}.o
done
echo

echo "** Activating RAID and LVM..."
raidstart -a && vgscan && vgchange -a y

echo "** Mounting root filesystem..."
mount -o ro -t xfs $ROOTDEV /sysroot || STARTSHELL=1

if [ $STARTSHELL -eq 1 ]; then
	## Start a rescue shell.  We mount a tmpfs filesystem
	## on /tmp as a place for command output, etc., since
	## the ramdisk may be mostly full.
	mount -t tmpfs none /tmp

	echo "** Starting shell (exit to continue)..."
	/bin/sh
	umount /tmp
fi

echo
echo "** Booting..."
echo

## This comes straight from the RedHat initrd.  This tells the kernel
## that the ramdisk (device major == 1, minor == 0) is the root filesystem.
## What we're reallying doing is tricking the kernel into not trying to
## mount root on its own, since with the pivot_root command, below,
## we replace the ramdisk root with our real root filesystem.
echo 0x0100 > /proc/sys/kernel/real-root-dev
umount /proc

cd /sysroot
pivot_root . initrd