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From: Grant Likely <grant.likely@secretlab.ca>
To: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>,
	Matt Fleming <matt@console-pimps.org>,
	Leif Lindholm <leif.lindholm@linaro.org>,
	Stephen Warren <swarren@wwwdotorg.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	linux-efi@vger.kernel.org,
	"linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"patches@linaro.org" <patches@linaro.org>,
	"H. Peter Anvin" <hpa@linux.intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	matt.fleming@intel.com
Subject: Re: [PATCH 1/4] Documentation: arm: [U]EFI runtime services
Date: Thu, 27 Jun 2013 07:23:23 +0100	[thread overview]
Message-ID: <CACxGe6uFkbuJ3BxM=A0Lu=jZQ79Ba8SmNsdBdTOO13szTfTZ=Q@mail.gmail.com> (raw)
In-Reply-To: <20130627013219.GA346@srcf.ucam.org>

On Thu, Jun 27, 2013 at 2:32 AM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> On Wed, Jun 26, 2013 at 07:38:19AM -0700, James Bottomley wrote:
>> The fixed virtual address scheme currently being looked at for x86_64 to
>> make SetVirtualAddressMap() kexec invariant doesn't work on 32 bit
>> because the address space isn't big enough.  For ARM, given that we've
>> much more opportunity to work with the vendors, can we just avoid
>> transitioning to a virtual address map and always just install a
>> physical mapping before doing efi calls?
>
> We can probably get away with that now, but it does risk us ending up
> with some firmware that expects to run in physical mode (boards designed
> for Linux) and some firmware that expects to run in virtual mode (boards
> designed for Windows). The degree of lockdown in the Windows ecosystem
> at present means it's not a real problem at the moment, but if that ever
> changes we're going to risk incompatibility.

What is the problem trying to be avoided by not using the virtual map?
Is it passing the virtual mapping data from one kernel to the next
when kexecing? Or something else?

g.

  reply	other threads:[~2013-06-27  6:23 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-25 18:10 [PATCH 0/4] arm: [U]EFI runtime services support Leif Lindholm
2013-06-25 18:11 ` [PATCH 1/4] Documentation: arm: [U]EFI runtime services Leif Lindholm
2013-06-25 18:46   ` Christopher Covington
2013-06-25 23:42   ` Stephen Warren
2013-06-26 13:20     ` Grant Likely
2013-06-26 13:53       ` Leif Lindholm
2013-06-26 13:59         ` Matt Fleming
2013-06-26 14:38           ` James Bottomley
2013-06-27  1:32             ` Matthew Garrett
2013-06-27  6:23               ` Grant Likely [this message]
2013-06-27  6:33                 ` James Bottomley
2013-06-27 14:37                   ` Matthew Garrett
2013-06-27 15:09                     ` James Bottomley
2013-06-27 15:37                       ` Grant Likely
2013-06-27 17:28                       ` Matthew Garrett
2013-06-27 14:54                   ` Grant Likely
2013-06-27 15:04                     ` James Bottomley
2013-06-27 18:32                       ` Russell King - ARM Linux
2013-06-27  9:00               ` Leif Lindholm
2013-06-27 14:38                 ` Matthew Garrett
2013-06-27 18:32             ` H. Peter Anvin
2013-06-26 18:32       ` Stephen Warren
2013-06-26 19:31         ` Leif Lindholm
2013-06-27 18:04           ` Stephen Warren
2013-06-27 20:11             ` Grant Likely
2013-06-26 13:13   ` Grant Likely
2013-06-26 14:04     ` Leif Lindholm
2013-06-26 14:35       ` Grant Likely
2013-06-27 14:22     ` Arnd Bergmann
2013-06-30  3:21   ` Rob Landley
2013-06-25 18:11 ` [PATCH 2/4] x86: efi: break efi_lookup_mapped_addr out to generic code Leif Lindholm
2013-06-26 13:30   ` Grant Likely
2013-06-26 13:32   ` Matt Fleming
2013-06-26 14:11     ` Leif Lindholm
2013-06-26 14:40       ` Matt Fleming
2013-06-25 18:11 ` [PATCH 3/4] arm: Add [U]EFI runtime services support Leif Lindholm
2013-06-25 18:20   ` Matthew Garrett
2013-06-26 13:46     ` Grant Likely
2013-06-26 13:46   ` Grant Likely
2013-06-26 13:54     ` Matt Fleming
2013-06-26 14:15       ` Borislav Petkov
2013-06-26 14:35         ` Grant Likely
2013-06-26 14:22     ` Leif Lindholm
2013-06-25 18:11 ` [PATCH 4/4] init: efi: arm: enable (U)EFI runtime services on arm Leif Lindholm
2013-06-26 13:24   ` Grant Likely

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