Hi,
Frank Vibrans III (frank.vibrans@amd.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/139
-gerrit
commit e42cf6b20097d3370cab840bc3223f690cde9747
I merged this with ebbfbd59115c1a8ccf380041aecd6e903dcf925a (current master HEAD) and my local changes for the Asus E35M1-M PRO. The result does not produce any serial output at all anymore. I haven't investigated any further than that yet ...
Florian