Getting /usr/src/ from SVN directly?

I plan on doing some kernel tweaking on CURRENT.  If my changes go
well I'll submit my changes to one of the devs.

I'm used to getting /usr/src/ via supfile using the "csup" command.  I
find that it would be a whole lot easier for me to access some sort of
anonymous SVN or CVS directly to populate my entire /usr/src/ folder.
That way, I would be able to make modifications directly in /usr/src/
and then use commands such as "svn status", "svn diff", and "svn
update" to view my changes, come up with a patch, and synchronize my
source tree [respectively] even after I have local changes.

So my question is, is there an SVN or CVS repository to do this sort
of thing?  Perhaps there is a Handbook page that explains this and I'm
just missing it?  The end result must be getting the same files under
/usr/src/ as when using the CURRENT supfile.

So for example:

  > cd /usr/
  > rm -rf src/
  > svn checkout svn://some.repos.freebsd.org/src-all/path/to/ ./src