I am wondering because of the (fairly) recent Spectre and Meltdown bugs that can only be fixed on the CPU if you either are running Linux or update your BIOS. However, most people do not want to run only Linux and many computers have not had a BIOS update released in a long time and will likely never get patched. So, would it be possible to mod a BIOS to load the updated microcode at boot time? And how much work would that take?
Hello,
some fixes could be done by the operating system (Linux, macOS, Windows, Android, ...), but other must be fixed by a microcode update.
The microcode is inside the BIOS or UEFI/BIOS. It could be exchanged through BIOS updates ... or done by advanced users with special tools.
Which mainboard and which processor do you have? Please be very exactly (vendor, model, revision)!
P.e. Intel Core i5 2500K and a ASRock Z77 Extreme3 -> BIOS update is here:
http://www.asrock.com/mb/Intel/Z77%20Extreme3/#BIOS
If there's no new BIOS update at your vendor, I can do the work for you.
Regards, MiMo