These instructions will take you through the step by step process of building and flashing a custom build of the Coreboot ROM to a Chromebook C201.
This guide expects you to have a Chromebook C201, and another ARM computer with Ubuntu installed. Specifically I used the Odroid XU2. You may be able to do this on an Intel platform, using a cross compiler. See the sidenotes section for more information.
Setting up your Ubuntu
Update your Ubuntu aptitude and install the dependancies we will need.
sudo apt update