[U-Boot] RK3399/RK3288 same-as-spl Option

[Philipp Tomsich]

Wadim,

> On 30.01.2019, at 13:50, Wadim Egorov <w.egorov at phytec.de> wrote:
> I want to know if there is a reason why the same-as-spl boot order option [1] was not added for the RK3288. Do the chromebooks or other RK3288 based boards don't want/need this option?
> 
For starters I don’t have a RK3288-based board or a Chromebook.
The code was designed to be generic enough to easily retarget to new boards.

It’s good to see that it’s not just our modules that face the challenge of requiring a configurable boot-order ;-) 
> It seems the RK3288 has the same Register that marks the boot source device:
>   RK3399_BROM_BOOTSOURCE_ID_ADDR: 0xff8c0010
>   For RK3288 it is 0xff700010. I know it is not documented in the TRM. But it works.
> 
I had asked Kever for the address (back in the day), as it was not documented neither for the RK3368 nor for the RK3399.
> Any opinions in reworking the RK3288 code to use this Register for "same-as-spl" boot?
> 
There’s a task in my to-do list to move most of the configuration in the GRF (e.g. selecting RGMII vs. GMII) to an ioctl-based scheme.
This resulted as the “best available choice” from a prior discussion between me an Simon.

If you want to tackle this, I would advise a DM-based solution for interfacing with our BootROM.

Thanks,
Philipp.,