[U-Boot-Users] Accessing git repository

...

Added, see http://source.denx.net/cgi-bin/gitweb.cgi?p=u-boot.git;a=commit;h=6bdf430660...

Is there already a document describing how to get U-Boot via git?

If you take the parameters off that url, http://source.denx.net/cgi-bin/gitweb.cgi, you'll see directions for getting the repository.