[coreboot] 16GB dimm on Sandy/Ivy Bridge status

[Patrick Rudolph]

Hi Iru,
>From T420 manual [1]:
"Memory: Up to 8GB DDR3 - 1333MHz (2 DIMM Slots)"

While it seems possible to use 16GB (2x 8GB), it isn't possible to use
16GB DIMMs.
I haven't tested by myself, but it seems like a hardware limitation.
Please provide raminit logs, just to make sure.

Regards,
Patrick

[1]
http://www.lenovo.com/shop/americas/content/pdf/notebooks/ThinkPad/t-series/ThinkPad%20T420-T520.pdf

On 2016-05-31 05:04 AM, Iru Cai wrote:
> Hi,
> 
> I'm tesing to see if the coreboot Sandy/Ivy MRC supports 16GB DIMMs.
> Here's my result.
> 
> I'm using a MT16KTF2G64HZ-1G6A1[1]. My machine is Lenovo T420 with
> i7-3630QM. With this module inserted (I've tested 16G+0 and 16G+8G),
> the system can light up, but it'll then get crashed.
> - with GRUB2 payload, it'll crash after the payload loads
> - with SeaBIOS payload with proprietary VGABIOS, I can see the prompt,
> and can boot to a GRUB or syslinux loader on my USB stick, but when I
> try to boot a system, it get crashed. If I boot to Memtest86+ on my
> USB stick, the system will crash when memtest starts to test the
> memory.
> 
> And another thing I can see is, the first boot can boot to payload,
> but the second boot will fail. I think it's caused by the MRC cache.
> 
> I'm still wondering if Sandy/Ivy northbridge can support 16GB DIMMs.
> I'll give a more detailed EHCI debug output later. According to [2], I
> think the incompatibility is an MRC issue instead of hardware
> incompatibility.
> 
> [1]
> https://www.micron.com/parts/modules/ddr3-sdram/mt16ktf2g64hz-1g6?pc={E1D8F1A9-3DFC-4BD2-8A1E-C26ED261EB0A}
> [2]
> http://www.intelligentmemory.com/fileadmin/download/compatibilitylist.pdf
> 
> Iru.