A microcode update is a binary blob loaded to CPU on boot.
Modern Intel CPUs itself are sort of a runtime environment that has its language and program RAM. By placing said blob onto BIOS(UEFI firmware) ROM, CPU can find it, fetch it and load onto internal mini-RAM during power-up.
The structure of BIOS/firmware ROM differs among board manufacturers and it cannot reliably be altered from Windows by Microsoft(its all the same in actuality though). Thus the microcode update blob must be integrated into and installed by manufacturer or as per their instructions.
Personally I don’t care. I only care about speed. I want the latest AGESA, but I opt Meltdown patches be left off.
The OS can update the Intel microcode at runtime just fine as well, and e.g. Linux and Windows offer such updates (like the one described by this very article). So BIOS/UEFI update/involvement is not needed.
Modern Intel CPUs itself are sort of a runtime environment that has its language and program RAM. By placing said blob onto BIOS(UEFI firmware) ROM, CPU can find it, fetch it and load onto internal mini-RAM during power-up.
The structure of BIOS/firmware ROM differs among board manufacturers and it cannot reliably be altered from Windows by Microsoft(its all the same in actuality though). Thus the microcode update blob must be integrated into and installed by manufacturer or as per their instructions.
Personally I don’t care. I only care about speed. I want the latest AGESA, but I opt Meltdown patches be left off.