Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #231718

Re: missing memory and the mystery of MTRRs

Show all headers | View raw

[Sorry about the lack of threading - I read this list via its Usenet 
group so I can't reply to the list.]

On Sun Feb 14 11:58:31 2021 "Alexander V. Makartsev" <avbetev@gmail.com>
wrote:

 > On Sat Feb 13 16:44:34 2021 Charlie Gibbs <cgibbs@surfnaked.ca> wrote:
 >
 >> [    0.012080] WARNING: BIOS bug: CPU MTRRs don't cover all of
 >> memory, losing 4800MB of RAM.

<snip>

 >> Is there some sort of HOWTO that covers this stuff?  Where do I go
 >> from here?
 >
 > Even if there is a "HOWTO" to learn some information, are you capable
 > of unpacking, disassembling and patching BIOS of your motherboard and
 > reassemble working image of it to flash into ROM?

I was afraid it might come down to that.

 > I suggest you to fiddle with BIOS settings first. Search for anything
 > that looks like memory related, like "Memory Hole", or something.
 > If this trial and error approach won't help, you can update your BIOS
 > as a last resort.
 > Since your motherboard is pretty old, and Intel has dropped all
 > support for Legacy products, you can't download BIOS updates from
 > Intel official source anymore. [1]
 > But you can still find them on archive sites. [2] I can't vouch for
 > this  site, but it looks like genuine BIOS update from Intel.
 > I have to warn you about security risks, because there could be a
 > small possibility, it was patched with malware, but considering this
 > BIOS is for an ancient hardware I have my doubts and personally I
 > would take the risk.
 > And besides, there are no other options.

Well, there is one other option: replace the motherboard.  Given that
it's becoming increasingly cranky on boot, that might be the way to go.
We had a power outage the other day, and when I tried to restart the
machine it would get past the Grub screen, then sit there forever with
a screen that was blank except for a blinking cursor.  It took about
half a dozen tries before it finally continued the boot process from
there.  I seem to recall that this happened last time we had a power
outage too.  For now I think I'll just keep my backups current, and
come the day it decides not to boot anymore I'll just replace it.

Thanks for the hints.

-- 
/~\  Charlie Gibbs                  |  Microsoft is a dictatorship.
\ /  <cgibbs@kltpzyxm.invalid>      |  Apple is a cult.
  X   I'm really at ac.dekanfrus     |  Linux is anarchy.
/ \  if you read it the right way.  |  Pick your poison.

Back to linux.debian.user | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

Re: missing memory and the mystery of MTRRs Charlie Gibbs <cgibbs@surfnaked.ca> - 2021-02-14 21:40 +0100
  Re: missing memory and the mystery of MTRRs Charles Curley <charlescurley@charlescurley.com> - 2021-02-14 22:50 +0100
  Re: missing memory and the mystery of MTRRs Andrei POPESCU <andreimpopescu@gmail.com> - 2021-02-15 09:20 +0100
    Re: missing memory and the mystery of MTRRs Henrique de Moraes Holschuh <hmh@debian.org> - 2021-02-16 17:20 +0100
  Re: missing memory and the mystery of MTRRs rhkramer@gmail.com - 2021-02-15 13:30 +0100

csiph-web