So I'm trying to build a basic initramfs using this tutorial on Ubuntu 14.04.5 LTS, and the last step "External file list" is throwing me off. I created the initramfs.cpio file from initramfs.list and placed it in my kernel build directory. After rebuilding and rebooting, the message does not appear, and it's presumably not booting from initramfs. Am i supposed to place it somewhere else? Also, do i need to generate an external file list for it to boot from initramfs properly?