given the large interest in using git by members of the community, I worked on an official read-only git mirror for general use. It has a website with code browser at http://code.coreboot.org/p/coreboot-git/ and the repo URL is git://code.coreboot.org/coreboot-git.git
It's automatically updated by a post-commit hook in the SVN repository.
Compared to the SVN upstream, it contains the full history (though not all seems to be reachable, eg. the "coreboot-v1" branch), which I cleaned up a bit to avoid confusing git-svn with our repository restructurings we did over the years. Since revision 4900 it's completely in sync with upstream, so most users shouldn't notice.