[U-Boot] Use of QEMU UEFI payland with persistent environment

[Simon Glass]

Hi Otavio,

On 8 December 2016 at 14:03, Otavio Salvador
<otavio.salvador at ossystems.com.br> wrote:
> On Thu, Dec 8, 2016 at 4:55 PM, Simon Glass <sjg at chromium.org> wrote:
>> Hi Otavio,
>>
>> On 8 December 2016 at 10:39, Otavio Salvador
>> <otavio.salvador at ossystems.com.br> wrote:
>>> Hello everyone,
>>>
>>> We are trying to automate some tests and one of the parts of the
>>> project requires the use of persistent environment.
>>>
>>> Due performance advantages we would like to use x86 with KVM to
>>> execute the tests however after booting QEMU with the UEFI payload it
>>> turns out the environment cannot be saved. Did someone ever made it
>>> work?
>>
>> Do you expect it to save to SPI flash? If so, does QEMU provide a way
>> to emulate that in a persistent file, or similar?
>
> The SPI flash would be ideal as we could keep it for reuse.
>
> It seems we can pass a file with:
>
> -drive if=pflash,format=raw,<file>
>
> But I did not find how to make it writable and make U-Boot to use it.

As an example, chromebook_link enables the SPI environment, so you
could copy the ENV_IS_IN_SPI_FLASH, etc. options from there.

To save it, 'saveenv' should work.

- Simon