Issue #592 has been updated by Tom Hiller.
In case it is missed in the linked github issue, the cause seems to related to this commit https://review.coreboot.org/c/coreboot/+/85161
---------------------------------------- Bug #592: Lenovo M920q can't use DIMM2 RAM slot https://ticket.coreboot.org/issues/592#change-2068
* Author: Coreboot Enjoyer * Status: New * Priority: Normal * Category: coreboot common code * Target version: none * Start date: 2025-04-15 * Affected versions: main * Related links: https://github.com/Thrilleratplay/coreboot-builder-scripts/issues/33
Also, it looks like a similar issue to https://ticket.coreboot.org/issues/462 * Affected hardware: Lenovo M920q ---------------------------------------- Building the current coreboot source, as well as commits 497298708c330deb479fbf3ee6a3acc8bff2a102, 640a41f3ee938b794b140218921e0fd63b1d9235 and 7945a31e9172ec2939cc1abc6036962a6efb601b, produces the firmware, that allows to initialize the motherboard if only DIMM1 RAM slot is filled. It fails to initialize, if DIMM1 RAM slot is empty and DIMM2 is filled, as well as if both DIMM1 and DIMM2 are filled. The issue is reproducible with different RAM sticks. I tried every possible combination with Kingston 32GB (2666MHz, CL 19-19-19-43) and Samsung 8GB (2400MHz, CL 17-17-17-39) -- the motherboard recognizes RAM sticks correctly, but still fails when the DIMM2 is filled with any RAM stick.
I have also attached the build config file, which uses most of the default options.
---Files-------------------------------- m920q-dimm2-config.txt (27.6 KB)