#!/bin/sh

PATH=/bin

/bin/busybox --install
busybox sleep 1
busybox mount -t proc proc /proc
busybox mount -t sysfs sysfs /sys
busybox mount -t devtmpfs none /dev

root_sfs=""
root=""
root_type="hwdevice"
overlay_dev=""
overlay_type="hwdevice"
singleuser=0

for param in `cat /proc/cmdline`; do
	case $param in
	root=*)
		root="${param##root=}"
		;;
	root_type=*)
		root_type="${param##root_type=}"
		;;
	root_sfs=*)
		root_sfs="${param##root_sfs=}"
		;;
	overlay_dev=*)
		overlay_dev="${param##overlay_dev=}"
		;;
	overlay_type=*)
		overlay_type="${param##overlay_type=}"
		;;
	single*)
		singleuser=1
		;;
	esac
done

if [ -z "${root}" ]; then
	echo "No root drive specified!"
	exec /bin/busybox sh
fi

# file system setup
mount_device() {
	local device="$1"
	local mountpoint="$2"
	local type="$3"

	case $type in
	qemu)
		mount -t 9p -o trans=virtio -oversion=9p2000.L $device $mountpoint
		;;
	hwdevice)
		while [ ! -e $device ]; do
			echo "Waiting for device $device"
			busybox sleep 1
		done

		mount $device $mountpoint
		;;
	*)
		mount -t $type $device $mountpoint
		;;
	esac
}

if [ ! -z "$root_sfs" ]; then
	mount_device "$root" "/images" "$root_type"

	if [ ! -e /images/${root_sfs} ]; then
		echo "${root_sfs} not found!"
		exec /bin/busybox sh
		exit 1
	fi

	mount -t squashfs /images/${root_sfs} /newroot
	umount -l /images
else
	mount_device "$root" "/newroot" "$root_type"
fi

if [ ! -z "$overlay_dev" ]; then
	mount_device "$overlay_dev" "/newroot/cfg/overlay" "$overlay_type"

	chroot /newroot /lib/libexec/init/overlay.sh etc /etc
else
	chroot /newroot mount --bind "/cfg/preserve/etc" "/etc"
fi

# cleanup mounts
umount -l /dev
umount /sys
umount /proc

# switch_root
unset -v overlay_dev root root_sfs overlay_type root_type

if [ "$singleuser" == "1" ]; then
	unset -v singleuser
	exec /bin/busybox switch_root /newroot /bin/bash
fi

unset -v singleuser
exec /bin/busybox switch_root /newroot /bin/init