electronjunkie

# Local filesystem mounting			-*- shell-script -*-
#
################################################################
# File:
# /scripts/local
#
# Root, or / in these notes is the initrd's (busybox) root,
# not your system's root!
#
# You need the aufs module for this to work.  To do this install
# aufs on your base install, add aufs to: /etc/initramfs-tools/modules
# Now using your target kernel run:
# mkinitramfs -o initrd.img <kernel-name>
#
# make a directory, copy an initrd to it then cd to it and:
#
# mv initrd.img initrd.img.gz
# gunzip initrd.img.gz
#
# make sure aufs exists somewhere in /lib/modules/<uname -r>/
# After modifying local script, etc do the following in the initrd's
# root folder where /bin and /lib etc is to create a new initrd:
#
# find ./ -print | cpio -H newc -o > ../newinitrd.img
#
# Now tell grub to use this initrd for a RO root filesystem
#
# Note fstab gets hosed, if you need an fstab, make sure this
# script reflects that.  I use an fstab for the default initrd for RW
# and none for RO, but you can make this script use a different one for
# RO if you want.
################################################################
# Parameter: device node to check
# Echos fstype to stdout
# Return value: indicates if an fs could be recognized
get_fstype ()
{
	local FS FSTYPE FSSIZE RET
	FS="${1}"

	# vol_id has a more complete list of file systems,
	# but fstype is more robust
	eval $(fstype "${FS}" 2> /dev/null)
	if [ "$FSTYPE" = "unknown" ] && [ -x /lib/udev/vol_id ]; then
		FSTYPE=$(/lib/udev/vol_id -t "${FS}" 2> /dev/null)
	fi
	RET=$?

	if [ -z "${FSTYPE}" ]; then
		FSTYPE="unknown"
	fi

	echo "${FSTYPE}"
	return ${RET}
}

# Parameter: Where to mount the filesystem
mountroot ()
{
	[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/local-top"
	run_scripts /scripts/local-top
	[ "$quiet" != "y" ] && log_end_msg

	wait_for_udev 10

	# If the root device hasn't shown up yet, give it a little while
	# to deal with removable devices
	if [ ! -e "${ROOT}" ] || ! $(get_fstype "${ROOT}" >/dev/null); then
		log_begin_msg "Waiting for root file system"

		# Default delay is 180s
		if [ -z "${ROOTDELAY}" ]; then
			slumber=180
		else
			slumber=${ROOTDELAY}
		fi
		if [ -x /sbin/usplash_write ]; then
			/sbin/usplash_write "TIMEOUT ${slumber}" || true
		fi

		slumber=$(( ${slumber} * 10 ))
		while [ ! -e "${ROOT}" ] \
		|| ! $(get_fstype "${ROOT}" >/dev/null); do
			/bin/sleep 0.1
			slumber=$(( ${slumber} - 1 ))
			[ ${slumber} -gt 0 ] || break
		done

		if [ ${slumber} -gt 0 ]; then
			log_end_msg 0
		else
			log_end_msg 1 || true
		fi
		if [ -x /sbin/usplash_write ]; then
			/sbin/usplash_write "TIMEOUT 15" || true
		fi
	fi

	# We've given up, but we'll let the user fix matters if they can
	while [ ! -e "${ROOT}" ]; do
		# give hint about renamed root
		case "${ROOT}" in
		/dev/hd*)
			suffix="${ROOT#/dev/hd}"
			major="${suffix%[[:digit:]]}"
			major="${major%[[:digit:]]}"
			if [ -d "/sys/block/sd${major}" ]; then
				echo "WARNING bootdevice may be renamed. Try root=/dev/sd${suffix}"
			fi
			;;
		/dev/sd*)
			suffix="${ROOT#/dev/sd}"
			major="${suffix%[[:digit:]]}"
			major="${major%[[:digit:]]}"
			if [ -d "/sys/block/hd${major}" ]; then
				echo "WARNING bootdevice may be renamed. Try root=/dev/hd${suffix}"
			fi
			;;
		esac
		echo "Gave up waiting for root device.  Common problems:"
		echo " - Boot args (cat /proc/cmdline)"
		echo "   - Check rootdelay= (did the system wait long enough?)"
		echo "   - Check root= (did the system wait for the right device?)"
		echo " - Missing modules (cat /proc/modules; ls /dev)"
		panic "ALERT!  ${ROOT} does not exist.  Dropping to a shell!"
	done

	# Get the root filesystem type if not set
	if [ -z "${ROOTFSTYPE}" ]; then
		FSTYPE=$(get_fstype "${ROOT}")
	else
		FSTYPE=${ROOTFSTYPE}
	fi

	[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/local-premount"
	run_scripts /scripts/local-premount
	[ "$quiet" != "y" ] && log_end_msg

	if [ "${readonly}" = "y" ]; then
		roflag=-r
	else
		roflag=-w
	fi

	# FIXME This has no error checking

	modprobe ${FSTYPE}
##########################################################################
###### Mod'd by Brian Phelps aka Electronjunkie ##########################

         mkdir /root/.tmpfs
         mkdir /root/.rootfs

         mount -r -t ext2 /dev/sda1 /root/.rootfs

         modprobe aufs
         modprobe loop
         mount -t tmpfs -o size=20M tmpfs /root/.tmpfs

         mount -t aufs  -o br:/root/.tmpfs=rw:/root/.rootfs=ro none /root/
         mv /root/etc/fstab /root/etc/fstab.defunct

#########################################################################

	# FIXME This has no error checking
	# Mount root

	[ "$quiet" != "y" ] && log_begin_msg "Running /scripts/local-bottom"
	run_scripts /scripts/local-bottom
	[ "$quiet" != "y" ] && log_end_msg
}