Intel IA32 CPU microcode...What is it
 

I am compiling a new kernel for mkd 8.1 due to application requirments and my stupidity. I ran make menuconfig, and I have gotten to this option for IA32 Microcode support. What is it? what is its usefullness? the help does not say much and the site it reffered me to is about as helpful.

Bring thread back to life RE: IA-32 microcode
 

Wow, only post I can find on the subject is 5 years old!?

Agreed, the documentation, menuconfig help and website are pretty spare of information on the subject, as is the Intel website itself. And the latest release of the code seems to be several years old too.

What it is: Updated code which temporarily replaces some/all of the programming inside the Intel CPU. It may contain bug-fixes, general updates, and improvements to some part of the CPU's built-in code.
It may not work for every CPU, and is only made in this case for certain Intel CPU's.
When loaded, it acts like a temporary flash of the CPU's ROM.

Why I posted this: I tried out the Microcode update driver for my 2.6.17.13 kernel. I use Slackware 11, and an MSI 6580 motherboard with an Intel P4 2.2Ghz and 80280 chipset (I think that's the number, off top of my head). I have had the driver compiled in for some time, and finally got around to seeing if it was of any use to me. Why? Because it's there, I guess.

Anyway, upon testing application of the code in the console, it returned an error "Bad Microcode - code contains errors". This could mean almost anything, from what I understand of the documentation. I tried it during a reboot, and the system sort-of hung during boot, repeating the same commands over and over a million or so times.
In the end, I had to boot from my CD and rm -f the script I made which was attempting to install the microcode because I couldn't boot normally. All is well now, a minor episode it was, but I wonder if anyone else has had any use for, success with, or information about this IA-32 Microcode driver thingy.
Such as: Is it still useful? For which CPU's and from what era? Has anyone installed it successfully? What was the result, if any? Is it just an urban myth?

SV