Updating CPU microcode possible?

[Nikos Chantziaras]

(I've tried posting this before I subscribed, since 
http://www.gnu.org/software/grub/grub-mailinglist.html says that 
"subscription to the list is not required to post a question." But that 
failed. So I'm trying again, after having subscribed...)


Hello.

Is it possible to update the CPU's microcode (an Intel CPU, in this 
case) with Grub? Meaning before the operating system starts.

I'm using Grub 2.02 beta 2 to boot three operating systems on my machine 
(Gentoo, FreeBSD and Windows 8.1.) It would be nice if I could make Grub 
do a microcode update before booting any of those operating systems. 
Right now, I am only able to a microcode update in Linux, after the 
kernel is booted.