[SOLVED] Gentoo install media boot hangs in EFI stub

[jharvell]

I am unable to boot the amd64 Gentoo install media from USB on a new system.

After the first GRUB menu option Boot LiveCD (kernel: gentoo) boots, I see the following on the screen, then nothing else:

[jharvell]

Update: I was able to successfully boot with the Ubuntu Desktop 24.04.2 LTS ISO image on USB. Once booted, I installed an ran the mprime torture test (from mersenne.org) for 12 hours with no errors.

From this result, I suspect the kernels in both the admincd and systemrescue images are not configured with the necessary support for the integrated GPU in the processor. I'll see if I can scrounge up a video card. But in the mean time, is there a way to boot the kernel so it will bring up the network and start an SSH server?

Edit: I was only able to boot from the Ubuntu image twice. I think the first time I tried booting, it reset a few seconds after choosing the grub menu option. Now when I try to boot, it either resets a few seconds after choosing the grub menu item or hangs. In the most recent attempt, I did not touch the keyboard and let grub boot the first menu item. After a few seconds, the video changed from black to kernel output showing a general protection fault.

So it looks like I some combination of bad RAM, CPU and/or motherboard. Not sure what to do other than try to RMA all three. I don't have another known good system compatible with any of these components where I can swap things to see where the problem is. Also, I'm surprised I was able to run 12 hours on the mersenne mprime torture test with no errors and have 4 successful passes through mtest86 on this system while booting Linux is so unstable. I did monitor CPU temps during the torture test, and they were mostly around 53 degC, spiking up to high 60s only briefly on occasion.

[jharvell]

After testing several combinations different DIMMs in different slots, it seems the problem is the two different DIMM kits are different enough from each other that the memory controller has problems handling the different performance between the two kits.

If I have only one kit installed (only tested one stick per channel) without trying to use the DDR-6400 XMP profile, the system always boots fine and is stable at DDR-5600. This is true regardless of which DIMM kit I am using.

I had no luck adjusting SOC/Uncore and DRAM voltages and DRAM impedances with all four DIMMs installed, no matter which DIMMs were in which slots.

When I tested kit A only with the DDR-6400 XMP profile, with DRAM performance set to either Competitive or Aggressive, the system would reset a few seconds into memtest86, and it would not boot the Gentoo admincd. When I tested kit B similarly, it was stable on Competitive but not on Aggressive.

My plan is to return kit A and continue with only the one memory kit. Once I get everything installed, I might try my luck with another kit to see if it is a better match for the kit I'm keeping.

From my research (an now experience), getting 4 DIMMs working well on AM5 is a challenge. Even if you get high performing CPU, DRAM and motherboard, you still have to get lucky to get good silicon for all three and get well matched DIMM kits.

[elover]