Re: [PATCH 0/6] introduce Arm FF-A support

Sudeep Holla
2022-08-02T08:38:19Z

Hi Simon,

On Mon, Aug 01, 2022 at 09:08:00PM -0600, Simon Glass wrote:
> Hi Sudeep,
>
> I'm not sure either. In particular I'm not sure why it would be easier
> to update whatever the FF-A software is than to update the DT, since
> presumably they are both in the firmware.
>

No, that is not the point. Someone who integrates must be aware of the
fact that since the firmware is updated, there is a dependency(though
created unnecessarily in this case) to even update the DT. Missing that
may result in spending time and finding it hard way. It may not happen
often but still happens and worth saving time and effort if this unneeded
dependency is wasn't there.

> I am talking about an issue in general and the same issue in
> particular with this series.
>

Since I might be missing to fully understand the issue, I may not be
of much help I am afraid.

> Can I suggest resending this series with a change log for each patch.
> Also please try to avoid #ifdefs and make sure to include
> documentation in doc/ including how this relates to the UEFI
> firmware-update effort that ARM/Linaro is undertaking. Also, what
> happened to the tests / sandbox driver?

To give a extremely brief summary on FF-A, it is an interface that enables
standard way of communication between different partitions in the system.
Partitions(also referred as VMs sometimes) can be either secure or
non-secure. Though it can be use to communicate between 2 non-secure VMs,
it is unlikely to be use there as it is not arch agnostic. So it will be
mainly used between secure and non-secure partitions and amongst secure
partitions.

--
Regards,
Sudeep