[coreboot] ECC RAM in coreboot-compatible X-series ThinkPads?

[Sam Kuper]

IIUC, conventional ECC RAM requires support from both the motherboard
and the CPU. This support is not present in current
coreboot-compatible X-series ThinkPads (e.g. X60, X200, X201, X220,
X230).

There was a discussion on the coreboot mailing list a couple of months
ago about RAM modules from "I'M Intelligent Memory". That discussion
focused on the fact that they are 16GB in size.
https://mail.coreboot.org/pipermail/coreboot/2017-February/083330.html

Potentially more interesting, though, is that at least some modules
from that company offer *integrated ECC*, which provides ECC in RAM
without requiring support from either the CPU or the motherboard:

http://www.electronicsbus.com/new-256mb-and-512mb-sdram-x8x16x32-memories-with-integrated-error-correction-ecc-from-intelligent-memory/

As I understand it, none of the modules from that manufacturer are
currently able to work in coreboot-compatible X-series ThinkPads, but
this did get me wondering:

- Are there any other manufacturers offering RAM modules with
integrated ECC that *are* compatible with those ThinkPads?

- Is there any other way to achieve ECC in coreboot-compatible
X-series ThinkPads? (E.g. use I'M Intelligent Memory 16GB ECC RAM
sticks but only address the first 8GB of each one?)

This is a shot in the dark, I know, but it seemed worth asking :)