File: //lib/firmware/4.14.138-89.102.amzn1.x86_64/readme-intel-06-4f-01
The microcode for Intel Broadwell-EP/EX (BDX-ML B/M/R0, family 6, model 79,
stepping 1) processors requires a kernel with specific commits present,
otherwise it might result in unexpected system behaviour. In order
to handle this, /usr/libexec/microcode_ctl/update_ucode script creates
necessary symlinks to make it available only on kernels with the aforementioned
patches present. The required patches are present in the following versions
of the kernel package:
AL AMI kernel 4.14.42 or newer
Please use the version of the kernel with the aforementioned patches when
running on Intel Broadwell EP/EX processors in order to have the microcode
updated.
If you want to avoid late loading of this ucode for a specific kernel, please
create "disallow-late-06-4f-01" file inside /lib/firmware/<kernel_version>
directory and run /usr/libexec/microcode_ctl/update_ucode script:
touch /lib/firmware/4.14.97-90.72.amzn2.x86_64/disallow-late-06-4f-01
/usr/libexec/microcode_ctl/update_ucode
If you want to avoid late loading of this microcode for all kernels, please
create "disallow-late-06-4f-01" file inside /etc/microcode_ctl/ucode_with
caveats directory and run /usr/libexec/microcode_ctl/update_ucode script:
mkdir -p /etc/microcode_ctl/ucode_with_caveats
touch /etc/microcode_ctl/ucode_with_caveats/disallow-late-06-4f-01
/usr/libexec/microcode_ctl/update_ucode
If you want avoid removal of the ucode file during cleanup, please remove the
corresponding readme file (copy of this file in /lib/firmware/<kernel_version>).
See /usr/share/doc/microcode_ctl/README.caveats for additional information.