the following patch was just integrated into master: commit b8b5b1e535becc2ff11767dced0d2a875e4b763e Author: Kyösti Mälkki kyosti.malkki@gmail.com Date: Tue Jul 10 13:10:24 2012 +0300
AMD: Fix GFXUMA with 4GB or more RAM
Northbridge code incorrectly adjusted the last cacheable memory resource to accomodate room for UMA framebuffer. If system had 4GB or more memory that last resource is not below 4GB and not the one where UMA is located.
There are three consequences:
The last entry in coreboot memory table is reduced by uma_memory_size.
Due the incorrect code in northbridge code state.tomk, end of last resource below 4GB, had not been adjusted. Incrementing that by uma_memory_size diverts a region possibly claimed for MMIO to RAM, as TOP_MEM is written.
Since the UMA framebuffer did not have IORESOURCE_CACHEABLE, it was ignored from the MTRR setup and not set uncacheable.
The setting of TOP_MEM and TOP_MEM2, as well as all the MTRRs, should be copied from BSP to all APs instead of deriving the data separately for each Logical CPU.
Change-Id: I8e69fc8854b776fe9e4fe6ddfb101eba14888939 Signed-off-by: Kyösti Mälkki kyosti.malkki@gmail.com
Reviewed-By: Patrick Georgi patrick@georgi-clan.de at Mon Jul 16 18:57:43 2012, giving +2 See http://review.coreboot.org/1217 for details.
-gerrit