Try compiling the S50 code and flash the content to your bios. It seams that there is no com port so you will need a USB debug device if you want to debug the boot process.
Oh yeah, I forgot to ask; 'compile' how? Is there a good wiki page?
The links here: http://www.coreboot.org/Welcome_to_coreboot
like these: http://www.coreboot.org/Build_HOWTO http://www.coreboot.org/Download_coreboot
should help.
Thanks, Myles