Roadmap 2024

[Stefan Kalkowski]

Hello,

On Fri, Dec 29, 2023 at 12:53:37PM +0100, Michael Grunditz wrote:
> >> I also would like to see a layer for USB controllers like EHCI and
> >> XHCI. I would be most happy if someone can walk me thru the pc usb
> >> stack. I would like to cut lose EHCI from it and use that in my ports.
> >> I believe that this is better than using linux driver all up to the
> >> actual stack.
> 
> > I'd be curious how your goals are aligned with Stefan's ongoing redesign
> > of Genode's USB infrastructure (explained at [2]) and his further plans
> > down the road. I'm hopeful that you might benefit from his line of work.
> 
> > [2] https://github.com/genodelabs/genode/issues/5021
> 
> I don't know. The plans linked is above what I want to do, if I understand 
> it right. I come from RISC OS lands , and in our rom we have EHCI,OHCI and 
> XHCI in seperate controller drivers. This all connects to what we call 
> USBDriver which is the main USB stack.
> 
> In Genode I would like to have something similar. It makes it very easy to 
> bring up on new platforms. In my case, Rockchip, I start USB ( power/phy) 
> from U-Boot. After that I only need to assign address and irq to the 
> controller driver. If Genode doesn't have native controller drivers at all 
> (in pc port) ( sorry haven't checked yet), I could try to bring in 
> controler drivers from BSD.
> 

I think using OHCI/EHCI/XHCI controller drivers written from scratch,
or ported from another OS then Linux is an orthogonal topic to the
recent attempts of re-designing the USB session. Driver implementation
can be done either by using the current session API or the envisioned
one. Anyway it might be good to target the newer session API, to limit
the overall efforts.

I was thinking of creating an USB multiplexer, independent of the
actual controller that serves either USB controller drivers acting as
clients as well as USB client device drivers. Thereby, we could
survive restarting USB host controller drivers in case of
malfunctions, which would increase robustness for all driver variants.
I'm not sure whether we shall schedule this vaque idea already for the
roadmap 2024, but I'm open to it.

Regards Stefan

-- 
Stefan Kalkowski
Genode labs

https://github.com/skalk | https://genode.org