Even a CPU has a little firmware inside. Since a lot of years it is possible to update it to fix little or bigger bugs. Usually this operation is done while updating your motherboard's BIOS, and the update is permanent. But thanks to the architecture of the linux kernel, we can update it at the last version every time we boot our OS. This is a really fast operation brought to you by microcode.ctl (in Ubuntu), and it permits to avoid waiting for an updated closed-source BIOS to solve bugs; it...