@SuperDicq @Suiseiseki @dushman
>If Intel or AMD wants me to run their updated microcode, why don't they give me the source code? I would gladly run an updated version if they made it free.

Few reasons, it would break licensing for the ISA itself (some x86 instructions are handled by microcode and not by the CPU circuitry itself without help), they would blow their specific CPU architecture wide open and other smaller issues.