As you may have noticed, svn up doesn't work anymore for old trees. svn switch (with or without --relocate) will fail with an error. You are stuck. But you wanted to keep that tree. Desparation fills your mind. And then you google for help and all you see is "subversion can't do such a switch". Before you trash your trees and bang your head against the wall:
Use my trick to beat svn into cooperation. Sit back and relax.
Enter a v3 tree. Type the two commands below and be happy.
svn switch svn://linuxbios.org/repository/coreboot-v3 . svn switch --relocate svn://linuxbios.org/repository/coreboot-v3 svn://coreboot.org/repository/coreboot-v3 .
Enter a v2 tree. Type the two commands below and be happy.
svn switch svn://linuxbios.org/repos/trunk/coreboot-v2 . svn switch --relocate svn://linuxbios.org/repos/trunk/coreboot-v2 svn://coreboot.org/repos/trunk/coreboot-v2 .
That's it. Have fun!
Regards, Carl-Daniel