Description: Due to the way Intel distributes their microcode packages, not all CPU microcodes are included in the newest packages from Intel. This has led to the intel-ucode package in Arch Linux to be delayed and remain on the Jan 2015 version, even though a new package was released by Intel on Nov. 2015 that provides some important fixes for newer Broadwell CPUs (such as the 3205u, which is in a Chromebook I installed Arch on). My guess as to why the Arch package has not been updated is has to do with the missing CPUs in the new Intel package. For instance, the i7-2630QM which is on a gaming notebook I use is supported by Intel's Jan. 2015 microcode, but not the Nov. 2015 one. My suggestion is to include all the intel microcode marked by Intel as "(latest)" in the repository package. There are currently 5 packages supplied by Intel marked as "(latest)". I'm not sure what to do from here, but there should be a way to load these 3 microcodes in order from oldest to newest that would allow the latest microcode for that specific CPU to be loaded. I believe it is very important to include these newer microcodes at least, because without it there various random errors on certain Intel chips.


Additional info:
Latest version in Arch repository: 20150121
Latest versions on Intel's site: 20140122, 20140913, 20150107, 20150121, 20151106


Steps to reproduce:
Try compiling a full Linux kernel in Arch Linux using an Intel Celeron-3205u. Compilation will fail due to an internal compiler error or a segfault at random points. The Nov. 2015 microcode fixes this. See task 46562 for more info.