Updated AMD Zen 1 Through Zen 3 CPU Microcode Published

[Mangix]

hopefully these microcode updates == fewer positives under /sys/devices/system/cpu/vulnerabilities/

[boxie]

The new bios updates are almost certainly to distribute the new microcode. For a long time CPU manufacturers have been cagy about allowing the OS to do the updates, preferring that the BIOS do it before the OS even loads.

What was referencing is the newer bios updates for the older X370 boards that allow them to run the newer Ryzen CPUs. My thoughts here are AMD might want some newer microcode to work against the newer bios better - like the article said - bring along the improvements of the last few years.

[Lycanthropist]

Has someone ever tried to reply to those update mails to ask about the changes? Maybe they'll answer if asked nicely.

[Developer12]

What was referencing is the newer bios updates for the older X370 boards that allow them to run the newer Ryzen CPUs. My thoughts here are AMD might want some newer microcode to work against the newer bios better - like the article said - bring along the improvements of the last few years.

The microcode and BIOS are shipped together. In fact, there's really nothing else in the BIOS that's CPU-specific other than "how to turn it on" (AGESA) so you don't really need to update microcode to "work with [the bios] better."

[evil_core]

Yes, and the PSP has little to do with the BIOS, motherboard, or x86 CPU cores. By the time the CPU cores come out of reset and start running the BIOS, the PSP has already basically done all of it's work. It's not involved in microcode loading.

I was talking about that CPU contains only RAM and truly read-only ROM, so microcode must be provided every-boot by motherboard BIOS or bootloader/operating-system.

And motherboard did less and less during the years, so today CPU is the one ruling motherboard(which mainly provides electrical connections today. Not sure if anything, except some discrete electronics is needed to be on mainboard)

[mangeek]

we are left to only speculate

I see what you did there. ;-)

[Soul_keeper]

I can't get the kernel to use the updated microcode.

kernel .config options:

#
# Generic Driver Options
#
# CONFIG_UEVENT_HELPER is not set
CONFIG_DEVTMPFS=y
CONFIG_DEVTMPFS_MOUNT=y
# CONFIG_DEVTMPFS_SAFE is not set
CONFIG_STANDALONE=y
CONFIG_PREVENT_FIRMWARE_BUILD=y

#
# Firmware loader
#
CONFIG_FW_LOADER=y
CONFIG_EXTRA_FIRMWARE="amd-ucode/microcode_amd_fam19h.bin"
CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware"
# CONFIG_FW_LOADER_USER_HELPER is not set
# CONFIG_FW_LOADER_COMPRESS is not set
# end of Firmware loader

kernel-firmware-20220124_eb8ea1b-noarch-1
dmesg
[ 1.158007] microcode: CPU0: patch_level=0x0a201204
md5sum
482491f4d4f94f480ff94362e5ff91bc /lib/firmware/amd-ucode/microcode_amd_fam19h.bin
-rw-r--r-- 1 root root 16804 Jan 24 22:03 /lib/firmware/amd-ucode/microcode_amd_fam19h.bin

kernel-firmware-20220318_681281e-noarch-1
dmesg
[ 1.158688] microcode: CPU0: patch_level=0x0a201204
md5sum
b7ace9dda9a1319dae2e75b8768870b9 /lib/firmware/amd-ucode/microcode_amd_fam19h.bin
-rw-r--r-- 1 root root 16804 Apr 9 19:40 /lib/firmware/amd-ucode/microcode_amd_fam19h.bin

kernel-firmware-20220411_f219d61-noarch-1
dmesg
[ 1.157711] microcode: CPU0: patch_level=0x0a201204
md5sum
ac0884e187cfa302e1c90b3e79e5ff1e /lib/firmware/amd-ucode/microcode_amd_fam19h.bin
-rw-r--r-- 1 root root 16804 Apr 11 10:48 /lib/firmware/amd-ucode/microcode_amd_fam19h.bin


It always shows the same patch_level.
Any ideas ?

[Soul_keeper]

I guess dmesg just won't show the updated version. It only shows what you booted with.

If enable pr_debug messages, then do echo 1 > /sys/devices/system/cpu/microcode/reload

[Mon Apr 11 15:09:08 2022] microcode: verify_and_add_patch: Added patch_id: 0x0a001058, proc_id: 0xa010
[Mon Apr 11 15:09:08 2022] microcode: verify_and_add_patch: Added patch_id: 0x0a001173, proc_id: 0xa011
[Mon Apr 11 15:09:08 2022] microcode: verify_and_add_patch: Added patch_id: 0x0a001229, proc_id: 0xa012

No idea if it is working.
cat /sys/devices/system/cpu/cpu0/microcode/version
0xa201204
The older version is still being shown.

Anyone else try this ?

[clouddrop]

I can't get the kernel to use the updated microcode.
...
It always shows the same patch_level.
Any ideas ?

For me I have to shutdown my machine, pull the PSU Plug and hold the power button for about 10 seconds to get new firmware to load. Afterwards the new version is shown during boot. I had been running with old firmware for quite some time before discovering this a couple of months ago.

[Soul_keeper]

I guess you are thinking of updating the bios. Using the amd released firmware with the kernel on boot don't permanently modify anything as far as I know.

Anyways, i'm unable to actually use the microcode released by AMD, and i'm pretty sure i've never been able to and i've spent a few years trying.
It just never loads, and searching the internet till my eyes hurt never gives an answer.