[coreboot] T520 2630QM 16GB DIMM

[tho at tricnet.de]

Hi,

TL;DR - Has anybody either successfully used 16GB DDR3 modules on  
SandyBridge, can rule it out, or has ideas about how to dig deeper?

I recently bought 2 crucial 16GB DDR3 SODIMM modules to upgrade my  
T520 (2630QM CPU) to 32 GB. As it didn't work I did some research and  
found a couple of postings blaming the problem on Intel not providing  
proper memory reference code (e.g.  
http://forum.notebookreview.com/threads/upgrading-ram.756463/page-2)  
preventing the BIOS from initializing the RAM.

When I looked for alternative BIOSes I came across coreboot. Compiled  
and installed it - works fine with 2*8GB modules. With one or two 16GB  
modules I still saw the SeaBIOS info but then it crashed. Adding  
memtest as a secondary payload and starting it worked, but memtest  
crashes instantly when it starts testing.

So I got a beaglebone for EHCI debugging. Please find the logs for  
2*8GB modules and 1*16GB + 1*8GB module at http://www.tricnet.de/t520/

There is already a related issue in the tracker -  
https://ticket.coreboot.org/issues/56 but I do not understand how  
there could be a pin missing (as suggested in the comment)? According  
to  
http://www.anandtech.com/show/7742/im-intelligent-memory-to-release-16gb-unregistered-ddr3-modules the column address needs one more line (A11) for the 8gbit chips, which is provided anyways because it is needed for regular row  
addressing.

I can afford to spend a bit more time on the issue but I'm not sure  
how to continue. Beside that I just found out, that Intel states 16GB  
max RAM for the 2630QM but 32GB for the 2720QM

http://ark.intel.com/de/products/52219/Intel-Core-i7-2630QM-Processor-6M-Cache-up-to-2_90-GHz
https://ark.intel.com/de/products/50067/Intel-Core-i7-2720QM-Processor-6M-Cache-up-to-3_30-GHz

So, do you have any ideas about how to continue?

Best,

Thomas