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microcode.ctl Debian Package

develper informations

The microcode_ctl utility is a companion to the IA32 microcode linux kernel driver, and it decodes and sends new microcode to the kernel driver for Intel IA32 family (Pentium Pro, PII, Celeron, PIII, Xeon, Pentium 4, etc.) and Intel x86_64 family processors;

The microcode update does not permanently alter the CPU and must be performed each time the system is booted.


This section should be about Debian package maintenance of microcode.ctl (in case of NMU, MIA,...). If you are searching information about microcode.ctl, check upstream site, Debian microcode.ctl package page or the ubuntu package page ubuntu package page.

  • load CPU microcode for the newer Intel processors of architecture i386 (Pentium families) and amd64.
  • microcodes are not distributed within the packages, it seems not enough free for Debian non-free. Intel already changed the license for us, but still non enough free (or not so clear).
  • microcodes: http://people.debian.org/~cate/files/microcode. I have the permission to distribute. Other distribution: please check the license and/or with Intel (IANAL, IMO it should be ok).
  • I pack it using git. You can find a public copy in git://git.debian.org/~cate/microcode.ctl.git . I use the following branches:
    the source as distributed by upstream, but without actual microcode file
    the source for debian package. It contain the following branches:
    files in debian/ directory, debian specific
    debian specific changes
    use dynamic buffer (and removed an improbable buffer overflow)
    correct my email
    correct makefile: make clean should clean all files
    correct typos in manpage
    other small changes, i.e. argument parsing, and removed overflow in case of huge filename in arguments.
  • upstream: http://www.urbanmyth.org/microcode/
  • microcodes now are also directly distributed by Intel, in http://downloadcenter.intel.com/. Look for "microcode" or select any CPUs (of i386 and amd86 architecture). The microcode file will contain the microcodes for all CPUs