Linux Processor Microcode Data File The microcode data file contains the latest microcode definitions for all Intel processors. Intel releases microcode updates to correct processor behavior as documented in the respective processor specification updates. While the regular approach to getting this microcode update is via a BIOS upgrade, Intel realizes that this can be an administrative hassle. The Linux operating system and VMware ESX products have a mechanism to update the microcode after booting. This SlackBuild repackages the official Intel microcode tarball, placing the microcode.dat file under /lib/firmware/microcode.dat, which can be later uploaded using microcode_ctl utility (available from SlackBuilds.org). If the iucode_tool (available from SlackBuilds.org) is installed on the system, this SlackBuild writes the microcodes with the file names expected by the Linux kernel firmware loader and places them under /lib/firmware/intel-ucode directory. In that case, the correct microcode is uploaded when the Intel microcode kernel's module is loaded. Please note that the method using the iucode_tool is preferred for multiple reasons, one being the deprecation of the kernel's interface used by the microcode_ctl utility. If you need to load the microcode early during the boot: 1) read https://www.kernel.org/doc/Documentation/x86/early-microcode.txt 2) read the manual for iucode_tool, especially about --write-earlyfw option 3) make sure your kernel has the followings: CONFIG_MICROCODE=y CONFIG_MICROCODE_EARLY=y CONFIG_MICROCODE_INTEL=y CONFIG_MICROCODE_INTEL_EARLY=y