Intel Microcode Update Utility for Linux

The microcode_ctl utility is a companion to the IA32 microcode driver
written by Tigran Aivazian <tigran@aivazian.fsnet.co.uk>. The utility
has two uses:

* It decodes and sends new microcode to the kernel driver to be uploaded
  to Intel IA32 processors. (Pentium Pro, PII, PIII, Pentium 4, Celeron,
  Xeon etc - all P6 and above, which does NOT include pentium classics).
  It also supports processors of the x86_64 architecture.
* It signals the kernel driver to release any buffers it may hold.

The microcode update is volatile and needs to be uploaded on each system
boot i.e. it doesn't reflash your cpu permanently, reboot and it reverts
back to the old microcode.

To use this utility you need to compile the kernel driver (found under
"Processor type and features"). The microcode itself can be found at
http://downloadcenter.intel.com/default.aspx and should be placed under
/lib/firmware/microcode.dat. Alternatively (or preferably) you can use
the *intel-microcode* SlackBuild available at slackbuilds.org to prepare
the microcode package to be readily used with the microcode_ctl utility.

To have the microcode updated each time at boot, start the included
init script from /etc/rc.d/rc.local:

if [ -x /etc/rc.d/rc.microcode_ctl ]; then
  /etc/rc.d/rc.microcode_ctl start
fi