So you decided that the existing cpu architectures (Intel's x86_64/i686 and ARM's 32-bit arm) platforms weren't up to the task for your next system? Instead, you opted for some magical and new architecture? What you desire is possible, but you should buckle up and prepare for a bumpy ride!
Keep in mind that ChromiumOS is based on a lot of upstream projects that we have not authored. That means you can't really get by with just porting ChromiumOS and forgetting about the rest.
For example, your architecture must already be supported by (at least):
ChromiumOS is based on Gentoo. Hopefully you've selected a processor that they already support (they support many already). You can find the current list here:
Find what you're looking for? Great! Life will be much easier and you should move on to the next section.
Your architecture not listed there? Sorry! You're first going to have to coordinate with the Gentoo maintainers in porting to your crazy architecture. Come visit us once you've gotten those sorted out.
More To Come!