[PATCH v2 2/2] sandbox: add bootmethod EFI boot-manager

[Heinrich Schuchardt]

On 10/19/24 01:01, Mark Kettenis wrote:
>> Date: Fri, 18 Oct 2024 19:26:01 +0200
>> From: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
> 
> Hi Heinrich,
> 
>> On 10/18/24 19:21, Simon Glass wrote:
>>> Hi Heinrich,
>>>
>>> On Thu, 17 Oct 2024 at 19:18, Heinrich Schuchardt
>>> <heinrich.schuchardt at canonical.com> wrote:
>>>>
>>>> The EFI boot-manager is the default method to boot EFI binaries.
>>>> We should be able to use it on the Sandbox.
>>>>
>>>> * Enable EFI boot-manager bootmethod on the sandbox.
>>>> * Adjust unit tests to reflect the additional boot method.
>>>>
>>>> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
>>>> Reviewed-by: Simon Glass <sjg at chromium.org>
>>>> Reviewed-by: Mattijs Korpershoek <mkorpershoek at baylibre.com>
>>>> ---
>>>> v2:
>>>>           no changes
>>>> ---
>>>>    arch/sandbox/dts/test.dts |  4 ++++
>>>>    test/boot/bootmeth.c      | 28 +++++++++++++++++-----------
>>>>    2 files changed, 21 insertions(+), 11 deletions(-)
>>>
>>> This is better, but I still see this.
>>>
>>> => bootflow scan
>>>        efi_var_to_file() Cannot persist EFI variables without system partition
>>>
>>> Please find a way to get rid of it. I can give some suggestions if you like.
>>>
>>
>> Would you, please, mind providing a rationale why you want this correct
>> message not to be written.
> 
> To me, warning about persisting EFI variables only makes sense if
> you're actually trying to persist an EFI variable.  But all we're
> doing here is scanning for possible bootflows.

The UEFI specification requires to create Boot#### variables which are 
non-volatile.

As the variables have to be non-volatile we try to persist them in a 
file. And the message describes that this fails.

> 
>> I expect the sandbox to behave as any other board and provide warnings
>> when they are adequate.
> 
> The warning doesn't make sense to me on non-sandbox boards either.
> 
> I suspect this is the code that autogenerates EFI Boot options, so
> code that sets Boot#### EFI variables.  But do we really care that we
> can't make those persistent?  The code will just regenerate them upon
> the next boot...

The same warning is written for any variable that cannot be persisted, 
e.g. for the Boot#### variables that you create manually.

Persisting auto-generated Boot#### makes sense as you may refer to these 
in the BootOrder or BootNext variables.

Best regards

Heinrich