My roadmap

[Norman Feske]

Hi Michael,

thanks for sharing your ambitious plan. It is intriguing!

On 18.12.20 15:22, Michael Grunditz wrote:
> Make the RK3399 port complete which for example includes PineBook Pro.
> HDMI will be easy, and I think eDP will be as well. The question is if
> doing it with DDE-Linux or from scratch. The RK3399 port is really
> only a exercise for me , since we already is on our way with a native
> port of RISC OS. But I guess a port of Genode can be useful for
> others.

I sense that DDE-Linux will become a hot topic the in 2021 and really
hope that the advances of tooling and methodology I hinted at in my
email, will make our life easier. Great to know that you anticipate this
direction.

> we haven't done natively is graphics. The only doc for DE 2.0 is a
> register description (VERY large document). No appnotes which makes it
> close to impossible to do without looking at BSP. We used simplefb ,
> that is , starting graphics in uboot and use the resulting
> framebuffer. NetBSD also does graphics this way.

My expectations regarding the Allwinner documentation were low. The
happier I was about the result of a quick web search [1]. That looks
quite useful to my untrained eye.

As a general plan, I will expose myself to the DDE-Linux approach as
much as possible to streamline the developer experience as much as I am
able to, and to document my work as I go. So I will definitely port the
graphics driver of the Linux kernel as a part of this challenge.

That said, by skimming over the DE document, I'm really tempted to play
around with the features directly, mapping them to Genode APIs in ways
that would be difficult when solely reusing the Linux driver code. But I
would not start with that before the Linux driver is working as a base line.

By the way, to get started with the DE, the code of the p-boot loader
[2] looks like a nice starting point. It is far from trivial. But it is
not daunting either.

[1] https://duckduckgo.com/?q=display+engine+allwinner+pdf
[2] https://megous.com/git/p-boot/tree/src/display.c

Cheers
Norman

-- 
Dr.-Ing. Norman Feske
Genode Labs

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