[coreboot] Are multiple GPUs with lots of memory (ex: 8GB+8GB) supported in coreboot?

Taiidan at gmx.com Taiidan at gmx.com
Sun Feb 11 22:04:31 CET 2018


On 02/11/2018 03:32 PM, Carl-Daniel Hailfinger wrote:

> On 10.02.2018 19:57, Arthur Heymans wrote:
>> "Taiidan at gmx.com" <Taiidan at gmx.com> writes:
>>> I would like to add this information to the wiki so I am wondering if
>>> anyone has successfully used for instance dual 8GB graphics cards with
>>> coreboot.
>>>
>> I don't think that this gpu memory is mapped into the linear memory
>> space. Such a GPU will typically have a PCI memory resource BAR that is
>> (only) 256M large (could be 512M or more these days).
>>
>>> I am not sure if this would be an issue due to coreboot only having
>>> 32bit MMIO space.
>>>
>> It depends a bit on how things are configured but with a fairly common
>> 2G mmio space below 4G I think it is unlikely for 2 external GPU's to be
>> an issue.
>>
>> It would of course be nice to have 64bit BAR support but that would
>> require substantial changes in the allocator and more importantly a lot
>> of time spend in a sane and thoughtful design...
> I think Myles Watson (not 100% sure) worked on an improved resource
> allocator with 64 bit resource support for v3. I do not know if it ever
> was merged in v4, or if that was instead a port of the v2 allocator to
> v3, in which case this would be mostly what we have now. The mails about
> this are mostly from 2009.
Thanks for the info everyone :]

That is a damn shame it didn't get merged, it would be quite useful to 
make coreboot a better server platform - it is needed for many nics, 
sr-iov, etc.

Do you have his email?



More information about the coreboot mailing list