Wang Wen,
I found following message in the coreboot-seabios log,
[ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-3.3.4-5.fc17.x86_64 root=UUID=c4d4a429-d880-4caa-831e-9e95b5595f67 ro
rd.md=0 rd.lvm=0
rd.dm=0 SYSFONT=True KEYTABLE=us rd.luks=0 LANG=en_US.UTF-8 console=ttyS1,115200n8
It shows "console=ttyS1,115200n8", it means the Linux kernel is using ttyS1 as the primary serial console, which is I/O port 0x2f8. But the seabios configure file shows seabios is configured using I/O port 0x3f8. it might be the problem.
Please run "make menuconfig" in seabios and reconfigure the serial port to 0x2f8, let us know any difference.
-Wang Fei