[PATCH v2 3/3] mx7ulp_com: add support for SPL

[Oleksandr Suvorov]

Hi Fabio,

On Thu, Sep 16, 2021 at 10:27 PM Fabio Estevam <festevam at gmail.com> wrote:
>
> Hi Oleksandr,
>
> On Thu, Sep 16, 2021 at 3:50 PM Oleksandr Suvorov <cryosay at gmail.com> wrote:
>
> > The SPL for this board is built with prepended DCD which includes DDR
> > training data (defined in imximage.cfg). So that the bootrom initializes
> > DDR using DCD before jumping to SPL.
> > Is it mandatory to move DDR init in C code for SPL-enabled setups?
> > We wouldn't be changing it for now :(
>
> If the SPL is currently not doing its minimum task of configuring DDR,
> why do we need SPL in the first place?

It's for a secure boot process, for running op-tee before u-boot.
You could refer to the model we use
https://docs.foundries.io/latest/reference-manual/security/secure-boot-imx.html#our-implementation
In that model, u-boot runs in a normal world.
Separating SPL is only the beginning of changes, so I'm trying to go
prepare changes to mainline step-by-step.
-- 
Best regards,

Oleksandr Suvorov
Software Engineer
T: +380 63 8489656
E: oleksandr.suvorov at foundries.io
W: www.foundries.io