Did you expect this surprise ? Instructions on how to install Ubuntu on CR48, straight from Chromium team ? I didn’t. May be they knew that Ubuntu guys will hack in to any hardware and install Ubuntu on it, so they provided official support, just like official jailbreaking.
Here is the info from Chromium website.
WhileÂ Chrome OS verified boot protects against unintended system modification by malicious or buggy software, the ability to hack your own device is an intentional design feature of Google Chrome notebooks. The instructions forÂ building your own version of Chromium OS, and installing it on a Cr-48Â are given elsewhere.Â Some enthusiasts, however, may want to install something completely different. This page provides an example, showing how the official Chrome OS software can coexist withÂ Ubuntu, a popular linux distribution.
These instructions work on the Cr-48 as originally shipped. There are several magic numbers that may differ on other Chromium OS-based machines.