public inbox for devel@edk2.groups.io
 help / color / mirror / Atom feed
From: "Andrew Fish" <afish@apple.com>
To: devel@edk2.groups.io, rafaelrodrigues.machado@gmail.com
Subject: Re: [edk2-devel] Memory Operation Mode
Date: Wed, 21 Aug 2019 12:55:16 -0700	[thread overview]
Message-ID: <BAEDC657-599C-43CE-984E-4CDBAFAF958D@apple.com> (raw)
In-Reply-To: <CACgnt79vnGVaJz7tLs77ziXio6mHksnLnHyrHp=bwWWqdMbRaw@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1266 bytes --]



> On Aug 21, 2019, at 11:55 AM, Rafael Machado <rafaelrodrigues.machado@gmail.com> wrote:
> 
> Hi everyone
> 
> I would like to ask for some help regarding one question.
> How do I know how the memory communication was set by the BIOS/MRC/FSP during the initialization process?
> For example, I would like to know if the memory controller is working with the memories in single channel or dual channel mode.
> 
> Didn't find anything related to this at the uefi spec.
> And seems the registers that may have this information are platform dependent, so no generic solution seems to be currently available.
> 
> Any idea about how to have this information?
> 

Rafael,

This is probably more of a PI kind of spec question, but the PI spec only really deals in how memory is discovered and registered with the PEI/DXE Core etc. There is not any infrastructure that abstracts this level of detail in PI. 

In general the kind of info you are looking for would only exist in SMBIOS records. You could start with the Type 16, 17, 18, and 19 SMBIOS records. The code that configure the memory knows a lot, but the only standard way to communicate this info is via SMBIOS. 

Thanks,

Andrew Fish

> Thanks and Regards
> Rafael R. Machado
> 


[-- Attachment #2: Type: text/html, Size: 2250 bytes --]

  reply	other threads:[~2019-08-21 19:56 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-21 18:55 Memory Operation Mode Rafael Machado
2019-08-21 19:55 ` Andrew Fish [this message]
2019-08-22 14:09   ` [edk2-devel] " Rafael Machado

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-list from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=BAEDC657-599C-43CE-984E-4CDBAFAF958D@apple.com \
    --to=devel@edk2.groups.io \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox