init

#!/bin/busybox sh
# initramfs init script
# /usr/src/initramfs/init

# defaults if no arguments where given:
crypt_source="/dev/sda4"
crypt_target="sda4_crypt"

bin_exist() {
	[ ! -e "/bin/${1}" ] && [ ! -e "/sbin/${1}" ] && die "Error ${1} not found."
}

die() {
	echo "Dropping you into a minimal shell..."
	exec /bin/sh
}

do_encrypt() {
	# dm-crypt - we need o encrypt first before anything other can happen
	echo "Waiting for encrypted filesystems to be opened..."
	cryptsetup -T 5 luksOpen "${crypt_source}" "${crypt_target}" || die
}

do_lvm() {
	#lvm - Looking for the volume groups if filesystem have been unlocked
	lvm vgscan --mknodes
	echo "Looking for available volume groups..."
	lvm vgchange -ay
}

do_mount() {
	#root filesystem - mounting root is always a good idea
	mount /dev/mapper/vg_gentoo-rootfs /newroot
}

do_switch() {
	#unmount pseudo FS - to make switch_root possible
	umount /sys
	umount /proc
	# switch root - work on real root from here
	echo "Got it, switching to real_root..."
	exec /bin/busybox switch_root /newroot /sbin/init ${CMDLINE}
}

main() {
	echo "Waiting for kernel and starting init..."
	sleep 2
	export PATH=/sbin:/bin
	# mount /proc and /sys
	mount -t proc proc /proc
	CMDLINE=`cat /proc/cmdline`
	mount -t sysfs sysfs /sys
	bin_exist "cryptsetup"
	do_encrypt
	bin_exist "lvm"
	do_lvm
	bin_exist "mount"
	do_mount
	do_switch
}

# starting init calling main
main