On 10.02.2018 19:57, Arthur Heymans wrote:
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
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
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.