[PATCH 3/5] bloblist: Tidy up the data alignment

[Simon Glass]

Hi Rasmus,

On Mon, 5 Oct 2020 at 23:41, Rasmus Villemoes
<rasmus.villemoes at prevas.dk> wrote:
>
> On 20/09/2020 02.49, Simon Glass wrote:
> > The intention which bloblists is that each blob's data is aligned in
> > memory. At present it is only the headers that are aligned.
> >
> > Update the code to correct this and add a little more documentation.
>
> Hi Simon
>
> I haven't read this patch in detail, but I have a general request
> regarding changes to the bloblist layout: Backwards compatibility - in
> the sense that, if the bloblist is generated by SPL from 2020.04, that
> should also be usable from a U-Boot proper as of 2021.01 etc.
>
> While I/we don't actually use bloblist currently, we have some ideas for
> what we might use it for on various boards. But, on at least one board,
> our SPL is stored in read-only storage after production, while we have
> redundant (and updatable) copies of U-Boot proper - so it's important
> that a future U-Boot can also grok a bloblist generated by earlier code.
>
> Is that guaranteed?

It is intended.

If we add a test for this we can provide that guarantee, yes. The test
will need to encode a pre-built binary bloblist though, not use the
code in master to generate it.

Regards,
Simon