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Date:   Tue, 28 Mar 2017 17:13:15 +0200
From:   Jan Kiszka <>
To:     Ard Biesheuvel <>,
        Matt Fleming <>
Cc:     "" <>,
        Linux Kernel Mailing List <>,
        Andy Shevchenko <>,
        "Bryan O'Donoghue" <>,
        Hock Leong Kweh <>,
        Borislav Petkov <>,
        Sascha Weisenberger <>
Subject: Re: [PATCH v2 5/7] efi/capsule: Prepare for loading images with
 security header

On 2017-03-28 15:49, Ard Biesheuvel wrote:
> On 24 March 2017 at 17:34, Jan Kiszka <> wrote:
>> The Quark security header is nicely located in front of the capsule
>> image, but we still need to pass the image to the update service as if
>> there was none. Prepare efi_capsule_update and its user for this by
>> defining and evaluating a EFI header displacement in the image located
>> in memory. For standard-conforming capsules, this displacement is 0.
>> Signed-off-by: Jan Kiszka <>
> Hello Jan,
> Thanks for taking the time to respin this.
> I played around with these patches a bit (I can't really test them
> since I don't have the hardware), and I am not really happy with the
> non-trivial changes to the generic code, only to allow a header
> displacement.
> So instead, I attempted to come up with an alternative which does not
> use a displacement field, but makes the core capsule routines work
> with a copy of the capsule header rather than mandating that it exists
> at the start of the buffer. This way, we can override the code that
> performs the copy, and make it originate from somewhere else.
> Could you please have a look at
> and tell me if that would work for you? I will send them out for
> proper review in any case, but to avoid confusion (if I missed
> something obvious), I don't want to send them out just yet.

There is more needed to make things work again, maybe around passing the
right image size. I'm looking into this.

Another observation: Making EFI_CAPSULE_QUIRK_QUARK_CSH select
EFI_CAPSULE_LOADER technically resolves the problem that the platform
code would otherwise need something from a capsule loader module.
However, a logical configuration would rather make the quirk depend on
the loader, wouldn't it? But I'm fine with both.


Siemens AG, Corporate Technology, CT RDA ITP SES-DE
Corporate Competence Center Embedded Linux

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