Adding support for new Ethernet PHY

[Christian Mauderer]

On 17/06/2019 18:16, Jonathan Brandmeyer wrote:
> What does it take to support a new Ethernet PHY in rtems-libbsd?  We've
> got a board with a TI DP83867 family member on it, which appears to have
> some support in FreeBSD.  How can that get pulled into a particular
> rtems-libbsd BSP?
> 
> Thanks,
> -Jonathan Brandmeyer
> 

Hello Jonathan,

if there is already a PHY driver for that PHY, you basically just follow
the steps from "How to Import Code from FreeBSD" in the libbsd
CONTRIBUTING.md. PHYs should be quite simple so it would be about:

- Add the files to libbsd.py
- Run ./freebsd-to-rtems.py -R and ./freebsd-to-rtems.py
- Commit the _unchanged_ imported files.
- Commit libbsd.py and (if necessary) changes.
- Add the driver reference to nexus-devices (if it is a officially
supported BSP) or to your application.

If it is supported, it should be most likely one of the files in
freebsd-org/sys/dev/mii. But to be honest: I didn't find it on a quick
look. Where did you find the support?

On the other hand: The DP83867E seems to have the default registers. If
you only need basic support without any extras, the generic ukphy (short
for UnKnown PHY) driver should work.

Best regards

Christian Mauderer