[coreboot] Porting to Asus M4A78-EM

Juhana Helovuo juhe at iki.fi
Sun Nov 28 20:43:47 CET 2010

Hello all,

I bought a new Asus M4A78-EM mainboard and started porting Coreboot to 
it. This board is very similar to M4A785-M board I had recently.

Since the chipset is almost the same, and the Super I/O is the same, I 
configured and compiled for M4A785-M and Coreinfo worked on the first 
try, VGA and all. No code changes were required. The BIOS for onboard 
VGA was extracted with the bios_extract utility.

I documented my initial results into the Coreboot wiki: 

Summary of results so far:

* Coreinfo: runs fine, both on serial and VGA.
* SeaBIOS: ok, both on serial and VGA. USB mouse attached makes SeaBIOS 
freeze on initialization.
* SeaBIOS can load Coreinfo, which again works.
* SeaBIOS can load FreeDOS from IDE CDROM. Seems to work ok.
* SeaBIOS freezes when loading Debian installer (syslinux) from IDE 
CDROM. No useful output on serial and VGA is blank.
* SeaBIOS can load Grub2 from SATA disk. Text "Welcome to Grub!" flashes 
on VGA, then the mainboard powers down, which makes debugging rather 

A boot log is attached. In this case FreeDOS was booted. Trying the same 
with Debian installer CD looks the same from the serial port (except for 
CD medium size).

Any good ideas how to proceed from here?
Do you see anything suspicious in the boot log?

Best regards,
Juhana Helovuo

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