#!/bin/sh
# Commands used:
# modprobe grep cat
# This script defines an alternative
# mount_root() function for 
# /sbin/init to run
# method of checking for root
TEST_for_ROOT(){
	if [ -d /mnt/ram -a -f /mnt/ram.cpio.gz -a \
	     -x /mnt/etc/init.d/ramload.sh ]
	then
		return 0
	else
		return 1
	fi
}

# default values
rootfstype=auto
root=ask
found=no
ROOT=

# Generate the list of block devices/partitions available
try_block_list(){
	for i 
	do
		case $i in
			# No ram devices or floppy
			*fd* | *ram* )
				continue
				;;
		esac
		[ -f $i ] || continue
		name=${i%/dev}
		name=${name##*/}
		dev=$(cat $i)
		major=${dev%:*}
		minor=${dev#*:}
		if [ "$root" = "ask" ] 
		then
			echo -n "Try /dev/$name?[Yn]"
			read ans
			case $ans in
				n | N )
				continue
				;;
			esac
		fi
		mount_dev_and_check $name $major $minor && return 0
	done
	return 1
}

# Mount device and look for some 
# "signature" files
mount_dev_and_check(){
	name=$1
	major=$2
	minor=$3

	mknod /dev2/$name b $major $minor
	if mount -nrt $rootfstype /dev2/$name /mnt 2>/dev/null
	then
		if TEST_for_ROOT 
		then
			ROOT=/dev/$name
			rootdev=$(($major*256+$minor))
			echo $rootdev > /proc/sys/kernel/real-root-dev
			found=yes
			return 0
		fi
		umount -n /mnt
	fi
	return 1
}	

# This mounts the root device using the routines above
mount_root() {
	mount -nt proc proc /proc
	mount -nt sysfs sysfs /sys
	mount -nt tmpfs tmpfs /dev2

	#Get the values of the various important parameters

	for i in $(cat /proc/cmdline); do
		case $i in
		root=*)
			root=${i#root=}
			;;
		rootfstype=*)
			rootfstype=${i#rootfstype=}
			;;
		esac
	done

	# There is no harm in loading all the FSTYPES
	# as they will be useful later on too!
	sIFS="$IFS"
	IFS=','
	set $FSTYPES
	IFS="$sIFS"
	for fs 
	do
		/sbin/modprobe -k $fs 2> /dev/null
		case "$fs" in
		*dos* | *fat* )
			# This is required for the mount command
			/sbin/modprobe -k nls_cp437 2> /dev/null
			/sbin/modprobe -k nls-iso8859-1 2> /dev/null
			;;
		esac
	done

	case $root in
	/dev/*)
		name=${root##/dev/}
		try_block_list /sys/block/$name/dev /sys/block/*/$name/dev
		
		;;
	ask | auto )
		try_block_list /sys/block/*/dev /sys/block/*/*/dev
		;;
	esac

	umount -n /dev2
	umount -n /sys
	umount -n /proc

	if [ "$found" != "yes" ]
	then
		echo "Could not mount the root file system"
		echo "Giving you a shell"
		exec sh
	fi
}