[Sound-open-firmware] SOF Zephyr and ARM support on STM32

[Liam Girdwood]

On Thu, 2019-05-23 at 09:28 +0000, Calvin AGENEAU wrote:
> Hello SOF subscribers,
> 
> I am currently in my 5th year of Master's degree as an intern at ST
> Microelectronics and my internship subject is the porting of SOF to
> the latest STM32 card.
> I come to you because I couldn't find information about the
> implementation of SOF in Zephyr and about ARM architecture, I only
> found information for Xtensa and Baytrail in the official
> documentation.
> Can someone gives me advices ?

This is still WiP internally, but I will put you in contact with the
Zephyr folks at Intel and see if we can create a branch to do this work
in public. What architecture is your DSP core ? I'm assuiming STM32 has
large ARM cores for Linux but a smaller core for DSP audio ?

The intention is to take the pipeline, topology, audio processing code
and some drivers an craete a Zephyr "process" for each pipeline using
the Zephyr EDF scheduler. This way things should be able to run on ARM
DSP target nicely.

There are some items that dont depend on this branch :-

1) Linux driver support. The driver should already build and run on ARM
but you will need to add some HW abstraction for the STM32. This will
allow the STM32 to send and receive IPC messages, load FW and boot FW.
I also think it will need device tree support but maybe Daniel has
already done this ?

2) Intrinsic or vectorisation support for ARM DSP. Some of the audio
processing component give better performance using SIMD optimisations.
The audio components have support for generic C processing and xtensa
intrinsics, but are missing any intrinsic support fro ARM (meaning
generic C version is used)

Thanks

Liam

> 
> Best Regards,
> Calvin Ageneau??
> 
> _______________________________________________
> Sound-open-firmware mailing list
> Sound-open-firmware at alsa-project.org
> https://mailman.alsa-project.org/mailman/listinfo/sound-open-firmware