[coreboot] coreboot AGESA support

[Marc Jones]

Tom Sylla wrote:
> This is mostly for the AMD guys, but is probably relevant to many on the list.
>
> Is anyone working on getting AGESA working in coreboot again? Back
> when we were deciding on a firmware solutin for our platform, the
> plan for LinuxBIOS AGESA support was a very good advantage for
> coreboot. After seeing the path for AGESA support languish for a few
> months, as well as Opteron support in general, we decided to use AMI
> instead (for various other reasons too). With AMI, every month or so,
> we get new AGESA drop, plop it in our build, and get various errata
> fixes, HT support, Barcelona fixes, etc.
>
> Is there any plan for this?
>
>   
Tom,
This was all officially announced at the coreboot summit. You can see 
the slides here:
http://www.coreboot.org/Coreboot_Symposium_2008

All the new Barcelona(fam10) code has been ported from AGESA v3 (which 
supports fam10 and K8 revf/g). Although it might seem like support has 
languished, I have been working very hard on it and I have many changes 
to upstream in the next few weeks.

The reason AGESA is not a drop-in is that AGESA v3 is Intel style 
assembly built by Microsoft tools. Even with all the work to port to C 
and GCC it is still a very big advantage to port from AGESA. Getting the 
errata and fixes is a matter of a code diff and port. This is the reason 
for keeping the ported code as close as possible to AGESA which has made 
for some unsightly coreboot code. The other challenge has been to make 
the port fit into the coreboot v2 architecture and to stay similar to 
the current K8 code. Sometimes that worked and other times it didn't.

In the future this will be different. New versions of AGESA (for new 
CPUs) are being written in C but they probably won't have support for 
fam10. Using the AGESA APIs we should be able to write wrappers that 
will allow us to just drop in new releases of AGESA.

We are committed to release GPL AGESA but we are not there yet. Since we 
had to port from ASM to C anyway, that is where I started. It was also 
the fastest path to helping our customers. After I get a few more bugs 
worked out and get B3 support done I can start on the release process 
for GPL AGESA.

Marc

-- 
Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:Marc.Jones at amd.com
http://www.amd.com/embeddedprocessors