Ryzen 3000 RDRAND microcode bug

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   Just now I read about a microcode bug here:
https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/

As it turns out, Ryzen 3000 series shipped with a broken random number generator. It gives you a 0xFFFFFFFF for the "random" number, every single time. For some systems (especially Linux) it made them unable to boot. Destiny 2 on Windows also can't run because of it.

Apparently it should've been fixed with a BIOS update, but it seems not to be the case even today. Article explained how to check if your system is affected, but it required Linux.

For anyone willing to do the check and share their results, I am grateful.
I hope ASRock had this problem fixed.

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ncc1701z Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 02 Aug 2019 Status: Offline Points: 6	Post Options Post Reply Quote ncc1701z Report Post Thanks(0) Quote Reply Topic: Ryzen 3000 RDRAND microcode bug Posted: 30 Oct 2019 at 5:28am
	Just now I read about a microcode bug here: https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/ As it turns out, Ryzen 3000 series shipped with a broken random number generator. It gives you a 0xFFFFFFFF for the "random" number, every single time. For some systems (especially Linux) it made them unable to boot. Destiny 2 on Windows also can't run because of it. Apparently it should've been fixed with a BIOS update, but it seems not to be the case even today. Article explained how to check if your system is affected, but it required Linux. For anyone willing to do the check and share their results, I am grateful. I hope ASRock had this problem fixed.

Ray62 Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 01 Jul 2018 Location: Germany, Berlin Status: Offline Points: 706	Post Options Post Reply Quote Ray62 Report Post Thanks(0) Quote Reply Posted: 30 Oct 2019 at 6:03am
	These problems are fixed since over two months. Since "AMD AGESA Combo-AM4 1.0.0.3 ABB" the RDRAND problem is fixed (for Linux systemd and Destiny 2 on Windows, but also for all SW using the RDRAND instruction). So a bios must contain at least this AGESA version, which should be the case for all consumer/mainstream boards from Asrock supporting Zen2 CPUs.
	Asrock Fatal1ty X370 Professional Gaming Offline Under test: MSI X570_MEG_ACE \| AMD Ryzen 9 3900X \| Scythe Mugen5 \| 2x16GB F4-3200C14D-32GTZ@3466 \| ASUS GeForce GTX 1080 Ti FE

ncc1701z Members Profile Send Private Message Find Members Posts Add to Buddy List Newbie Joined: 02 Aug 2019 Status: Offline Points: 6	Post Options Post Reply Quote ncc1701z Report Post Thanks(0) Quote Reply Posted: 31 Oct 2019 at 3:25am
	You would be right, that should've been the case. Except the mainboard in the article didn't get the fix even now. Granted, it's a rather niche board (Asrock Rack X470D4U), but that situation shouldn't happen. Oh well, maybe it's just a special case and I'm just being paranoid

shmerl Members Profile Send Private Message Find Members Posts Add to Buddy List Groupie Joined: 23 Oct 2017 Status: Offline Points: 612	Post Options Post Reply Quote shmerl Report Post Thanks(0) Quote Reply Posted: 31 Oct 2019 at 11:23am
	On Linux you can also explicitly load latest microcode, even if motherboard firmware still ships the old one: https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/tree/amd-ucode