AMD microcode
This article describes updating the microcode for AMD processors.
For AMD GPU firmware see the corresponding GPU driver article instead.
Installation
Emerge
Microcode updates for AMD processors are provided by sys-kernel/linux-firmware package. Install the package via:
root #emerge --ask sys-kernel/linux-firmwareKernel
In order to load the CPU microcode the following kernel options should be enabled:
Processor type and features --->
[*] CPU microcode loading support
[ ] Intel microcode loading support
[*] AMD microcode loading support
Modules do not work for early microcode, so make sure microcode loading is built-in not a module.
Configuration
There are multiple ways how to update the microcode.
Built-in firmware
This way the firmware files will be built directly into the kernel.
Firmware blob files selection
You can either include all the available AMD firmware files to the kernel or select just the one specific for your CPU.
All firmware files
This setup simply builds all the firmware blobs into the kernel. This can be achieved by the following kernel optionsː
Device Drivers --->
Generic Driver Options
(amd-ucode/microcode_amd.bin amd-ucode/microcode_amd_fam15h.bin amd-ucode/microcode_amd_fam16h.bin amd-ucode/microcode_amd_fam17h.bin amd/amd_sev_fam17h_model0xh.sbin) External firmware blobs to build into the kernel binary
(/lib/firmware) Firmware blobs root directory
Every option must be set as built into the kernel, not as a kernel module.
The CONFIG_EXTRA_FIRMWARE option allows specifying multiple firmware files by listing them space-separated.
Specific firmware only
This way you only include the firmware suitable to your current CPU family. The CPU family identification can be obtained from /proc/cpuinfo:
user $grep -F -m 1 "cpu family" /proc/cpuinfocpu family : 22
In this example the CPU belongs to the AMD CPU family 22.
The CPU family identificator listed in /proc/cpuinfo uses the decimal numeral system.
Note that after the K8 AMD has started to refer to the various microarchitectures as "AMD Family xxh", where "xxh" is the hexadecimal CPU family value from the CPUID. For example, AMD Family 10h really is the official AMD name for the K10 microarchitecture. Following this convention AMD is even using AMD Family 0Fh for the previous K8 microarchitecture (CPUID
0F hexadecimal or 15 decimal).The following table helps to identify the right firmware blob file for given CPU family identificator:
| Firmware blob file | Decimal | Hexadecimal | Family name | Year | Examples |
|---|---|---|---|---|---|
| amd-ucode/microcode_amd.bin | 16 | 10h
|
K10 | 2007 | Phenom, Phenom II, Athlon II |
| 17 | 11h
|
Turion | 2008 | Athlon X2, Sempron X2, Turion X2 | |
| 18 | 12h
|
Llano, Fusion | 2009 | A- and E2-Series APU with Radeon HD graphics, Athlon II, Sempron X2 | |
| 20 | 14h
|
Bobcat | 2011 | C- and E-Series APU with Radeon HD graphics | |
| amd-ucode/microcode_amd_fam15h.bin | 21 | 15h
|
Bulldozer, Piledriver, Steamroller, Excavator | 2011 | FX series, A-Series APU with Radeon HD graphics, Opteron 6200/6300 |
| amd-ucode/microcode_amd_fam16h.bin | 22 | 16h
|
Jaguar, Puma | 2013 | A-series and E-Series APU with Radeon HD graphics |
| amd-ucode/microcode_amd_fam17h.bin | 23 | 17h
|
Zen, Zen+, Zen 2 | 2017 | Ryzen 3|5|7|9, Threadripper, EPYC |
| amd/amd_sev_fam17h_model0xh.sbin | SEV (Secure Encrypted Virtualization) firmware update for models in the range 00h to 0fh[1][2]
| ||||
| amd/amd_sev_fam17h_model3xh.sbin | EPYC 7xx2[3] (Zen 2) | 2019 | SEV firmware update for models in the range 30h to 3fh[4]
| ||
| (none yet) | 25 | 19h
|
Zen 3 | 2021 | Ryzen 5000 series (not all models), EPYC 7xx3 |
The previously identified CPU specific firmware blob file (in this example CPU family 22) needs to be built into the kernelː
Device Drivers --->
Generic Driver Options
(amd-ucode/microcode_amd_fam16h.bin) External firmware blobs to build into the kernel binary
(/lib/firmware) Firmware blobs root directory
Every option must be set as built into the kernel, not as a kernel module.
Initrd
You can load the microcode with the initrd. This way the firmware blobs are not inside the kernel, which will instead look for them in the loaded initrd.
Kernel
In order to use the initrd, you have to enable it in the kernel:
General setup --->
[*] Initial RAM filesystem and RAM disk (initramfs/initrd) support
Firmware files preparation
First create the specified directory and cd into it. It doesn't have to be in /tmp but the kernel/x86/microcode part is necessary.
user $mkdir -p /tmp/amd-ucode/kernel/x86/microcodeuser $cd /tmp/amd-ucodeThen we concatenate all the AMD firmware files into a single file. As before the path and filename of the output file must not be altered.
user $cat /lib/firmware/amd-ucode/microcode_amd*.bin > kernel/x86/microcode/AuthenticAMD.binThen we will create a cpio archive in /boot/amd-uc.img using bsdcpio from app-arch/libarchive:
root #echo kernel/x86/microcode/AuthenticAMD.bin | bsdcpio -o -H newc -R 0:0 > /boot/amd-uc.imgAlternatively, enable the initramfs USE flag for sys-kernel/linux-firmware to get /boot/amd-uc.img.
GRUB2 configuration
Since the image file /boot/amd-uc.img is one of the recognized ones by GRUB2 we just need to regenerate grub config.
root #grub-mkconfig -o /boot/grub/grub.cfgFound linux image: /boot/vmlinuz-4.18.12 Found initrd image: /boot/amd-uc.img /boot/initramfs-4.18.12.img
It should show that it found the /boot/amd-uc.img file.
Building the kernel
Rebuild and install the kernel as usual.
Verification
After the next reboot with the new kernel, you should see a similar output:
user $dmesg | grep microcode[ 0.584603] microcode: microcode: updated early to new patch_level=0x06000832 [ 0.868036] microcode: CPU0: patch_level=0x06000832 [ 0.868116] microcode: CPU1: patch_level=0x06000832 [ 0.868196] microcode: CPU2: patch_level=0x06000832 [ 0.868277] microcode: CPU3: patch_level=0x06000832 [ 0.868360] microcode: CPU4: patch_level=0x06000832 [ 0.868451] microcode: CPU5: patch_level=0x06000832 [ 0.868538] microcode: CPU6: patch_level=0x06000832 [ 0.868619] microcode: CPU7: patch_level=0x06000832 [ 0.868718] microcode: Microcode Update Driver: v2.01 <tigran@aivazian.fsnet.co.uk>, Peter Oruba
The first line contains the microcode: updated early log message in case a microcode update was performed during the boot.
References
- ↑ Revision Guide for AMD Family 17h Models 00h-0Fh Processors (PDF, page 6)
- ↑ [PATCH] linux-firmware: Update AMD SEV firmware (LKML, John Allen, commit pushed, 18 Jun 2019)
- ↑ Revision Guide for AMD Family 17h Models 30h-3Fh Processors (PDF, page 6)
- ↑ [PATCH] linux-firmware: Update AMD SEV firmware (LKML, Josh Boyer, signed-off, 20 Jul 2020)