From: Matthew Garrett <mjg@redhat.com>
To: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Takao Indoh <indou.takao@jp.fujitsu.com>,
nhorman@tuxdriver.com, hpa@zytor.com, kexec@lists.infradead.org,
linux-kernel@vger.kernel.org, horms@verge.net.au,
Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>,
tglx@linutronix.de, mingo@redhat.com, vgoyal@redhat.com
Subject: Re: [PATCH v2][EFI] Run EFI in physical mode
Date: Thu, 13 Jan 2011 17:41:39 +0000 [thread overview]
Message-ID: <20110113174139.GB22823@srcf.ucam.org> (raw)
In-Reply-To: <m1bp3kbu6t.fsf@fess.ebiederm.org>
On Thu, Jan 13, 2011 at 09:16:26AM -0800, Eric W. Biederman wrote:
> Matthew Garrett <mjg@redhat.com> writes:
>
> > We're seeing issues with some Dell hardware when EFI is run in physical
> > mode - it seems that Windows uses virtual mode, so the physical path is
> > never exercised. I'm not sure that changing the default to physical is
> > going to be possible without compatibility issues.
>
> The bootloaders use physical mode, and there shouldn't be a separate
> physical vs virtual mode. It should be the same code with or without
> relocations applied. At worst we can set virtual address to the
> physical address, on buggy boards.
Haven't we learned that failing to mimic Windows as closely as possible
in firmware interactions is a recipe for immense disaster yet? We'll
never successfully blacklist every broken machine.
> Honestly if the problem is the EFI code is so buggy we can't use it
> in physical mode the answer is almost certainly not to use the
> buggy EFI code.
Which would be fine, except...
> The only bits that I don't think have an alternative are the firmware
> variable accesses. Which are a nice to have, but not a show stopper
> anywhere.
It's not typically possible to set up the bootloader without EFI
variable acccess.
--
Matthew Garrett | mjg59@srcf.ucam.org
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2011-01-13 17:42 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-16 23:07 [PATCH v2][EFI] Run EFI in physical mode Takao Indoh
2010-12-14 3:43 ` Kenji Kaneshige
2010-12-14 18:01 ` Takao Indoh
2010-12-16 20:22 ` H. Peter Anvin
2011-01-13 16:38 ` Matthew Garrett
2011-01-13 17:16 ` Eric W. Biederman
2011-01-13 17:41 ` Matthew Garrett [this message]
2010-12-14 22:38 ` Takao Indoh
2010-12-15 23:42 ` Eric W. Biederman
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-all 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=20110113174139.GB22823@srcf.ucam.org \
--to=mjg@redhat.com \
--cc=ebiederm@xmission.com \
--cc=horms@verge.net.au \
--cc=hpa@zytor.com \
--cc=indou.takao@jp.fujitsu.com \
--cc=kaneshige.kenji@jp.fujitsu.com \
--cc=kexec@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=nhorman@tuxdriver.com \
--cc=tglx@linutronix.de \
--cc=vgoyal@redhat.com \
/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