Andrew,
FYI, work to rewrite GDB's sparc support has just started - it was long overdue for an overhaul. See the branch: kettenis_sparc-20030918-branch. If you're interested in contributing code, contact me. However, I suspect, even someone running tests would help.
I tried checking this out, but got the following error:
cvs -d :pserver:anoncvs@sources.redhat.com:/cvs/src co -r kettenis_sparc-20030918-branch
cvs [checkout aborted]: must specify at least one module or directory
I checked out the modules, but didn't see anything there. Could you please point me in the right direction?