Intel microcode

This article describes the process of updating the microcode on Intel processors.

Kernel
You need to activate the following kernel options:

Software
You can now install the microcode

And a tool to manipulate it

Configuration
After emerging, generate the microcode cpio archive using :

Grub 1.x
Add the generated microcode to your kernel command line as an initrd parameter (this should be done even if you don't use an initrd image in order to boot, the microcode update merely leverages the initrd hooks):

Grub 2.x
Change this small section of /etc/grub.d/10_linux from:

To this:

Regenerate your grub.cfg with:

Reboot and you're all done.

Verification
Here is an example of a CPU with no available microcode updates or the system was not configued to load them properly:

Here is the same CPU but with microcode updates being applied successfully:

Kernel
You need to activate the following kernel options:

Software
You can now install :

OpenRC
You can now start microcode-ctl:

To start microcode-ctl at boot time, add it your boot runlevel:

systemd
See: Systemd. Simply make sure that the Microcode loader is set as a module in the kernel configuration as noted above. You don't need to add a service or do anything else.

Software
You can install the officially published microcode package and let it automatically processed by

And you can use this tool to identify your actual CPU signature(s)

to find the appropriate filename(s) for the listed signature(s) using the output of the earlier emerge command (which you saved or logged).

Alternatively, your might wish to process and install a custom file (the official Intel package intended for Linux users and thus the Gentoo ebuild might be a little old at times while you can find more recent microcodes from unofficial sources):

This example above will automatically identify your CPU signature (-S) and install (-K) the matching microcode binary found in the specified location to the default firmware location (/lib/firmware/) under the intel-ucode directory (see the manual for more information).

Check the result and take a note (you will need this information in the next step):

Kernel
You need tho enable and configure the following kernel options:

Rebuild and install your kernel the same way you normally would.

Verification
After the next reboot, you should see something like this: