Re: Fwd: [RFC,PATCH v2] efi: Add support for a UEFI variablefilesystem

From: joeyli
Date: Thu Sep 13 2012 - 04:13:31 EST

On Thu, 2012-09-06 at 13:40 +0800, Jeremy Kerr wrote:
> From: Matthew Garrett <mjg@xxxxxxxxxx>
> The existing EFI variables code only supports variables of up to 1024
> bytes. This limitation existed in version 0.99 of the EFI
> specification,
> but was removed before any full releases. Since variables can now be
> larger than a single page, sysfs isn't the best interface for this.
> So,
> instead, let's add a filesystem. Variables can be read, written and
> created, with the first 4 bytes of each variable representing its UEFI
> attributes. The create() method doesn't actually commit to flash since
> zero-length variables can't exist per-spec.
> Updates from Jeremy Kerr <jeremy.kerr@xxxxxxxxxxxxx>.
> Signed-off-by: Matthew Garrett <mjg@xxxxxxxxxx>
> Signed-off-by: Jeremy Kerr <jeremy.kerr@xxxxxxxxxxxxx>
> ---
> v2: Add check for < 4-byte writes

Do we have plan to create a new kobject add to /sys/firmware/efi for
provide a fixed mount point to efivars fs?
e.g. /sys/firmware/efi/efivars

Or we just direct reuse current /sys/firmeware/efi/vars? But, that means
we need think for the backward compatibility if choice reuse vars

Thanks a lot!
Joey Lee

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