On 12/07/2018 16:56, Graeme Gregory wrote:
On Thu, 12 Jul 2018 at 16:50, Rob Herring <robherri...@gmail.com> wrote:
On Thu, Jul 12, 2018 at 9:37 AM Graeme Gregory
<graeme.greg...@linaro.org> wrote:
On Thu, 12 Jul 2018 at 16:30, Udit Kumar <udit.ku...@nxp.com> wrote:
Hi Mark
-----Original Message-----
From: Mark Brown [mailto:broo...@kernel.org]
Sent: Thursday, July 12, 2018 8:20 PM
To: Udit Kumar <udit.ku...@nxp.com>
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>; Architecture Mailman List
<boot-architecture@lists.linaro.org>; nd <n...@arm.com>; arm.ebbr-discuss
<arm.ebbr-disc...@arm.com>
Subject: Re: [Arm.ebbr-discuss] [RFC] uefi: Account for SetVariable() not
working
at runtime
On Thu, Jul 12, 2018 at 02:19:49PM +0000, Udit Kumar wrote:
Do any existing implementations change variables from non-volatile
to volatile?
The UEFI spec is explicit about which variables are volatile and which are not.
Simply relaxing non-volatile to volatile in the general case doesn't
seem like a useful approach to me.
I believe at boot-time, UEFI specs will be followed for volatile and
non-volatile
variables.
Having this in statement EBBR, will help those platform, which cannot expose
non-volatile variables at runtime.
If nothing currently does it the chances that anything will actually cope well
seem minimal. Like Daniel said it seems more likely to break things - if the
variables are defined as being non-volatile then the OS is unlikely to be
checking
at runtime if that's the case or not unless it's explicitly written to work with
EBBR. If an error is generated because a non-volatile variable can't be set
then
that should at least fall into whatever error handling code is there to cover
normal rutime failures which has some chance of doing something sensible.
Right,
There will be some breaks or say diversion from UEFI specs.
If we need to follow UEFI specs 'Table 10. Global Variables' on such platform
where we cannot write to NV storage at runtime, then in either case
1/ passing OS as no-efi-runtime or
2/ Returning errors/not saving to NV storage
is violation of UEFI spec.
Which divergence is acceptable ?
Neither, fix the specs with proper updates to support your use-case.
Or fix your platform to obey the specs you have chosen.
How do you add firmware storage to existing platforms?
Why can't UEFI spec be updated to handle such reduced functionality
platforms if this is important?
Its not like appropriate people are unknown to Linaro.
That is exactly what we discussed in the meeting today. Right now UEFI
2.7 doesn't cover the use case we care about. Resolution was to put a
note into EBBR v0.6 stating that this is a problem and asking for
feedback on preferred solution. The end result will either be a
clarification in UEFI, or a note in EBBR. We will coordinate with the
USWG on this issue.
g.
_______________________________________________
boot-architecture mailing list
boot-architecture@lists.linaro.org
https://lists.linaro.org/mailman/listinfo/boot-architecture
