About Beaglebone Black device tree

[Chris Johns]

On 2020-02-10 19:18, Christian Mauderer wrote:
> 
> Hello Chris,
> 
> thanks for your input. I'm still not entirely happy with the location
> too. But I also don't know a better one. Currently I know of the
> following necessary cases:
> 
> - Build a dtb from FreeBSD sources (or some other source).
> 
> - Build an overlay from some RTEMS source (for example: Using an i2c
> adaption layer for libbsd instead of using the i2c hardware directly).

Thank you the summary. I see the issue.

> - For some targets with a simple bootloader that can only load one
> device tree binary: Merge the overlays with the base tree.

OK. Can this be done in a tool like rtems-boot-image to merge them.

> The dts from FreeBSD could either be imported in libbsd or pulled from a
> download (note: either many files for all dts, dtsi and headers or one
> big file for the complete FreeBSD source tree). The overlays for RTEMS
> are a bit less easy: There should be a place for them in RTEMS
> somewhere. And I really don't know where would be a good one. Do you
> have any suggestions?

It is tricky.

I suppose FDT is used to describe the hardware and we should be using it 
in RTEMS for drivers. If we locate them outside the rtems.git repo it 
will create an awkward relationship. I agree we do need to capture them 
somehow.

I am not sure what we need to do to handle these files.

Chris