[coreboot] How to make graphical issue go away with 4GB of ram

Kyösti Mälkki kyosti.malkki at gmail.com
Sat Jun 30 20:01:31 CEST 2012

On Sat, 2012-06-30 at 18:18 +0200, Denis 'GNUtoo' Carikli wrote:
> Hi,
> me and Kyösti Mälkki(kmalkki on IRC) figured out how to workarround the
> following problem:
> If I installed 4GB of ram in the m4a785t-m the screen comes up,however
> it's black.
> If I only installed 2GB of ram it worked fine.
> I made a patch(I'll send it right after that email) but it seem to break
> graphics for the case where 2GB of ram is installed.
> So I wonder what would be the correct fix(a fix that would work for
> every cases).
> Explanation of the patch that will be sent right after the mail:
> "basek - mmio_basek;" should be 1048576 (1G):
> According to Kyösti Mälkki the correct value for the sizek is 1048576.
> So I looked for what could create that size and found that.
> I'm not convinced that "basek - mmio_basek" is the right fix but at
> least we're in the right direction.

My explanation of the issue: uma_memory_size must reduce the size of the
last RAM resource _below_ 4GB. It now touches the last RAM resource,
even if located over 4GB.


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