[PATCH] efi_loader: Allow also empty capsule to be process

[AKASHI Takahiro]

Hi,

On Wed, Jul 19, 2023 at 08:28:41AM +0200, Michal Simek wrote:
> 
> 
> On 7/18/23 17:41, Heinrich Schuchardt wrote:
> > On 13.07.23 16:35, Michal Simek wrote:
> > > Empty capsule are also allowed to be process. Without it updated images
> > > can't change their Image Acceptance state from no to yes.
> > 
> > Is there any documentation describing the usage of empty capsule to set
> > the image acceptance state?
> 
> I actually don't know about documentation. I was talking to Ilias to make
> sure that documentation is up2date because there are missing couple of
> things there.

Sughosh should have more to say here about A/B update.

> I am testing A/B update and if you setup oemflags to 0x8000 then capsules
> are not automatically accepted and waiting for acceptance capsule to be
> passed.
> When I tested it I found out that they are not process that's why I created
> this patch.

The path you tried to modify is only executed by "efidebug capsule update"
or more specifically via the runtime service, UPDATE_CAPSULE.

But this API is NOT officially supported in the current capsule implementation
(at least, in my initial intention).
The only way to invoke capsule updates is to reboot the system.
If you want to test A/B update, please do the reboot.

-Takahiro Akashi


> But definitely someone should check that logic that the patch is
> right based on intention how these empty capsules should be used.
> I am actually not quite sure how revert capsules should be used and how to
> revert only certain image if you use multiple images in the same bank.
> 
> Thanks,
> Michal