[coreboot] Geode LX: SDRAM initialization with no DIMMs

Marc Jones marc.jones at amd.com
Thu May 15 21:03:15 CEST 2008

llandre wrote:
> Hi all,
> I'm porting coreboot to custom hardware (Geode LX-based).
> The system is equipped with on-board DDR chips (no DIMMs). Since OLPC 
> platform has similar SDRAM configuration, I was thinking about using 
> the mainboard/olpc/btest/auto.c file as a starting point. However this 
> file includes GX2 stuff
> #include "northbridge/amd/gx2/raminit.c"
> so it seems it refers to old version of hardware.
> Which LX-based platform do you suggest to use as starting point instead?
> TIA,
> llandre
> DAVE Electronics System House - R&D Department
> web:   http://www.dave.eu
> email: r&d2 at dave-tech.it
I recommend that you look at the way it was done in the dbe61 mainboard 
inv2 or the dbe62 in v3. You will need to make adjustments based on the 
memory configuration and speed. You need to make a virtual spd for the 
memory init code to use. If you need to reverse engineer the settings 
the MSRs to look at are the following:



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

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