_sed(){
	local t=$4.'$$$'
	cp $4 $t || exit 1
	sed "${@}"
	cmp -s $4 $t || {
		unlink $t
		return 0
	}
	echo "Failed sed: $*"
	return 1
}

# patch is too unsafe with modifyed scripts. use script instead
cd "$1" &&
_sed -i -e 's:^\(\. /etc/initrd\.scripts\)$:\1\n. /etc/syspnp:' init &&
_sed -i -e 's:^\(r*u*n* *.*busybox --install -s\)$:\1\n\npnp_init:' init &&
_sed -i -e 's:^\(\t*good_msg .Loading modules[ \.]*.\)$:\1\n\tsyspnp:' init &&
_sed -i -e 's:^\(# If devtmpfs is mounted, try move it to the new root\|udevsettle\)$:mod_unload\n\n\1:' init