[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

ANNOUNCEMENT: Intel/AMD x86 CPU microcode update system in non-free

Hello all,

I would like to bring to your attention the improved support for system
processor (CPU) microcode updates, for x86/i686/x86-64/amd64 systems
that was recently added to [non-free] Wheezy.

System Processors from Intel and AMD may need updates to their microcode
(sort of a control sequence for the processor) to operate correctly.
These updates fix bugs/errata that can cause anything from incorrect
processing, to code and data corruption, and system lockups.

It is very difficult to know for sure whether you need a microcode
update or not, but it is not safe at all to just ignore them.  You might
not notice their effect and have precious data silently corrupted, or an
important program silently misbehave.  Or you could experience one of
those unexplainable and infrequent software issues (such as kernel oops,
application segfaults) or hardware issues (including sudden reboots and

Releases of new microcode updates are more frequent on young processors,
but the release of new microcode updates for older processors do happen.

The BIOS (or EFI) updates the CPU microcode during boot, however most of
the time either the motherboard vendor won't issue frequent BIOS/EFI
updates, or the user won't install such updates.  For these reasons, the
system processor is likely to be running with outdated microcode on a
vast number of systems.

The operating system has to pick up the slack.

Unfortunately, the license of the microcode update data from AMD and
Intel are not compatible with the Debian Free Software Guidelines.
Therefore, microcode update data will be available through the non-free
distribution.  The new processor microcode update system is available
for both non-free Wheezy and non-free Squeeze (through the backports


Processor microcode updates are ephemeral, and last only until the next
processor reset or power off.  They have to be reapplied at every boot,
and also when the system wakes up from suspend or hibernation.

Please install the "amd64-microcode" package (for systems with AMD
processors), or the "intel-microcode" and "iucode-tool" packages (for
systems with Intel processors).

"iucode-tool" is available in "contrib", the other two packages are
available in "non-free", so you will have to enable both contrib and
non-free in /etc/apt/sources.list.

Debian Squeeze users can find up-to-date versions of these packages in
the official backports repository (in the contrib and non-free

Microcode updates will be applied immediately when the microcode
packages are installed or updated: you don't have to reboot.  You will
have to keep the packages installed, though: as explained above, the
microcode updates have to be reapplied at every boot.

You can check which version of the microcode your processors are running
by looking for "microcode" lines on /proc/cpuinfo.  This information is
only available on recent kernels (such as the Wheezy kernel).

  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh

Reply to: