Updated AMD Zen CPU Microcode Lands In Linux-Firmware Tree

[mlau]

**** User will not able to flash previous BIOS once upgrading to this BIOS version.

they fixed an exploit in the bios and do not allow you to downgrade to a vulnerable one again.

[FireBurn]

Yeah, I feel your pain. Been down this road myself yesterday. What worked for me is copying the new firmware (microcode_amd_fam17h.bin) into the relevant directory (/lib/firmware/amd-ucode/) (make sure the permissions are correct and you backup the old file you are replacing!), followed by a version of the instructions here worked for me with my Ryzen 2600 on Lubuntu 18.04.3 with kernel 5.3.x. The key bits for me were:

echo 1 > /sys/devices/system/cpu/microcode/reload

followed by (as root)

update-initramfs -u

and rebooting to test.

I built the firmware into my kernel image and my /lib/firmware folder is the linux-firmware git repo, I'm definitely loading it, I'm assuming the bios is recent enough to have it included (https://www.asus.com/Motherboards/RO...HelpDesk_BIOS/ 2801 from last month)

[metallurge]

I built the firmware into my kernel image and my /lib/firmware folder is the linux-firmware git repo, I'm definitely loading it, I'm assuming the bios is recent enough to have it included (https://www.asus.com/Motherboards/RO...HelpDesk_BIOS/ 2801 from last month)

Your CPU (2400G) has a CPUID of 0x810F10. According to MCEdb, your current firmware is 0x08101016, dated 2019-04-30. You appear to have it already.
My CPU (2600) has a CPUID of 0x800f82. According to MCEdb, my current firmware is 0x800820d, dated 2019-04-16. I didn't have it already because I am on LTS Ubuntu and their lib-firmware lags significantly, plus I am on a pretty old BIOS on this particular x370 motherboard, so I had to install it manually to get it.