Re: [gentoo-user] Microcode update AMD

[Volker Armin Hemmann <volkerarmin@googlemail.com>]

On Tuesday 18 January 2011 09:34:14 Mark Knecht wrote:
> On Tue, Jan 18, 2011 at 8:16 AM, Mark Knecht <markknecht@gmail.com> wrote:
> > On Tue, Jan 18, 2011 at 7:38 AM, Paul Hartman
> > 
> > <paul.hartman+gentoo@gmail.com> wrote:
> >> On Mon, Jan 17, 2011 at 10:29 PM, William Kenworthy <billk@iinet.net.au> 
wrote:
> >>> The bios microcode update is likely an enable setting rather than
> >>> the
> >>> bios actually updating the cpu.  You need to do some reading/asking
> >>> of
> >>> the manufacturers (not here) if it bothers you.
> >> 
> >> Thanks for the links, I didn't realize they made the microcode data
> >> available separately.
> >> 
> >> From Intel's download site for the microcode data:
> >> 
> >> "The microcode data file contains the latest microcode definitions for
> >> all Intel processors. Intel releases microcode updates to correct
> >> processor behavior as documented in the respective processor
> >> specification updates. While the regular approach to getting this
> >> microcode update is via a BIOS upgrade, Intel realizes that this can
> >> be an administrative hassle. The Linux Operating System and VMware ESX
> >> products have a mechanism to update the microcode after booting. For
> >> example, this file will be used by the operating system mechanism if
> >> the file is placed in the /etc/firmware directory of the Linux
> >> system."
> > 
> > Thanks for the info Paul.
> > 
> > For kicks I tried it on an Intel DH55HC MB running an Core i5-661.
> > 
> > 1) Created /etc/firmware
> > 2) Downloaded the Intel microcode-20101123.tgz file
> > 3) Enabled the /dev/cpu/microcode option under Processor Types and
> > Features 4) Rebuilt the kernel and rebooted
> > 
> > I see this in dmesg:
> > 
> > mark@firefly ~ $ dmesg | grep micro
> > [    0.495337] microcode: CPU0 sig=0x20652, pf=0x2, revision=0x9
> > [    0.495436] microcode: CPU1 sig=0x20652, pf=0x2, revision=0x9
> > [    0.495535] microcode: CPU2 sig=0x20652, pf=0x2, revision=0x9
> > [    0.495635] microcode: CPU3 sig=0x20652, pf=0x2, revision=0x9
> > [    0.495751] microcode: Microcode Update Driver: v2.00
> > <tigran@aivazian.fsnet.co.uk>, Peter Oruba
> > mark@firefly ~ $
> > 
> > On this machine the message doesn't change whether the microcode file
> > is located in /etc/firmware or not so I don't know how to tell if the
> > process worked but the processor doesn't need any updates or whether
> > it didn't work at all.
> > 
> > - Mark
> 
> OK, I got it to load by hand:
> 
> 1) emerge microcode-ctl
> 
> which also emerges microcode-data. Unfortunately microcode-data looks
> to be out of date. Add microcode_ctl to the boot level:
> 
> rc-update add microcode_ctl boot
> 
> 2) Unzip and untar the microcode file from Intel.
> 
> 3) The above emerge placed the microcode.dat file in /lib/firmware,
> not /etc/firmware as suggested by the kernel, so I loaded the newer
> one from Intel by hand using microcode-ctl:
> 
> 
> firefly firmware # microcode_ctl -f /etc/firmware/microcode-20101123.dat
> microcode_ctl: writing microcode (length: 430080)
> microcode_ctl: microcode successfuly written to /dev/cpu/microcode
> firefly firmware # dmesg | grep micro
> [    0.495755] microcode: CPU0 sig=0x20652, pf=0x2, revision=0x9
> [    0.495853] microcode: CPU1 sig=0x20652, pf=0x2, revision=0x9
> [    0.495952] microcode: CPU2 sig=0x20652, pf=0x2, revision=0x9
> [    0.496050] microcode: CPU3 sig=0x20652, pf=0x2, revision=0x9
> [    0.496168] microcode: Microcode Update Driver: v2.00
> <tigran@aivazian.fsnet.co.uk>, Peter Oruba
> [ 2647.731262] microcode: CPU0 updated to revision 0xc, date = 2010-06-10
> [ 2647.731982] microcode: CPU1 updated to revision 0xc, date = 2010-06-10
> [ 2647.732815] microcode: CPU2 updated to revision 0xc, date = 2010-06-10
> [ 2647.733608] microcode: CPU3 updated to revision 0xc, date = 2010-06-10
> firefly firmware #
> 
> Now the microcode revision appears to be updated.
> 
> I suspected that if I renamed the file in /etc/firmware to
> 'microcode.dat' maybe it would load automatically at boot time but it
> didn't so I moved it to lib/firmware where microcode_ctl does load it.
> 
> NOTE: There is a /etc/conf.d/microcode_ctl config file but it doesn't
> see to include a path for microcode so I guess at this time I'm stuck
> overwriting the /lib/firmware directory until I learn more.
> 
> Cheers,
> Mark

and that is all the intel stuff. For AMD all you have to do is:
modprobe -r microcode && modprobe microcode