[lkml]   [2009]   [Mar]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: Linux* Processor Microcode Data File
On Friday 13 March 2009, Dragoslav Zaric wrote:
>I found this on web site
>Tigran Aivazian, author of the IA32 microcode driver and Microcode
>Update Utility for Linux explained:
>"The answer to your question is that some Intel CPUs (just like any
>other hardware or software) contain bugs
>and, fortunately, their architecture is flexible enough to provide a
>way to fix those bugs by means of loading the
>microcode update on the fly, i.e. while the OS is running with no need
>to reboot (in fact, rebooting or otherwise
>resetting the CPU causes the update to be lost and requires to run the
>update again)."

And what runs this update? I saw it apply once in the dmesg output, about 3
full powerdown reboots ago, never since, and the code is still there in

AMD quad core 9550 here, stepping 03.

>So when you reboot system, you reset CPU to original state, and after
>that you must apply microcode, and this
>is what is actually doing right now, you put microcode in folder
>/etc/firmware and after boot microcode is loaded.
>So I think for CPU hotplug it is also natural that microcode is loaded
>after plugging, because you can not use
>microcode from boot process. Maybe kernel should have database of
>tested microcodes, so when you plug CPU
>appropriate microcode is loaded.

Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
The only thing that experience teaches us is that experience teaches us
-- Andre Maurois (Emile Herzog)

 \ /
  Last update: 2009-03-13 15:59    [W:0.048 / U:13.820 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site