Re: missing memory and the mystery of MTRRs
[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.
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