BITS

Tool from Intel called “BIOS Implementation Test Suite” that can do several things including handling microcode:
– https://biosbits.org
– https://github.com/biosbits/bits
– https://github.com/mkorthof/bits

Linux

• load/update microcode using pkg:
  • Debian
    - Intel: apt install intel-microcode iucode-tool
    - AMD: apt install amd64-microcode
    - Doc: /usr/share/doc/{intel,amd64}-microcode/README.Debian.gz
  • CentOS/RH:
    - microcode_ctl
    - https://git.centos.org/summary/rpms!microcode_ctl.git
     
• load/update intel microcode manually:
  - get latest tgz from intel: see below
  - backup/copy files: /lib/firmware/intel-ucode
  - check kernel config: grep MICROCODE /boot/config-*
  - run iucode_tool:

  /usr/sbin/iucode_tool -tb -lS /lib/firmware/intel-ucode/*

  - update initramfs: update-initramfs -u -k all

• reloading microcode:
  echo 1 > /sys/devices/system/cpu/microcode/reload
  or: rmmod cpuid; modprobe cpuid

• show version:
  dmesg | grep microcode or: grep microcode /proc/cpuinfo

• skip loading microde on boot:
  add to grub cmdline: dis_ucode_ldr

Windows

Microsoft includes certain microcode updates in Windows CPU’s. For example: KB4090007, KB3064209, KB2970215.

• load/update microcode:
  using a VMWare driver called “cpumcupdate”: https://labs.vmware.com/flings/vmware-cpu-microcode-update-driver

Get Microcode

Download the latest version from Intel:
https://downloadcenter.intel.com/download/27431/Linux-Processor-Microcode-Data-File?v=t.