Device Tree Blob for Beaglebone Black?

[Vijay Kumar Banerjee]

On Sun, Feb 23, 2020 at 11:46 PM Alan Cudmore <alan.cudmore at gmail.com>
wrote:

> Hi Christian,
> Thanks for the quick response. I followed the instructions in the
> docs.rtems.org manual and generated the dtb from the FreeBSD commit
> that Vijay suggested. It still resulted in an exception in the same
> function.
>
> Do you know if a specific commit of rtems-libbsd is required to work
> with that dtb?
> I tried master, and then the "5-freebsd-12" branch.
>
> Thanks,
> Alan
>
> Hi Alan,

I checked with the usb01 and ping01 tests running on libbsd master
and the dtb from the commit mentioned by Christian. I can't reproduce
the error and it seems to run as expected. I'm not sure where the
error might be coming from. Below I'm pasting the contents of my uEnv.txt
If the error isn't in the uEnv, I can send you my sd card image(offlist) so
that you
can try that on your board and that might give some hint on what was going
wrong.

```
setenv bootdelay 5
uenvcmd=run boot
boot=fatload mmc 0 0x80800000 rtems-app.img ; fatload mmc 0 0x88000000
am335x-boneblack.dtb ; fdt addr 0x88000000; bootm 0x80800000 - 0x88000000
```

Best regards,
Vijay

> On Sun, Feb 23, 2020 at 11:32 AM Christian Mauderer <list at c-mauderer.de>
> wrote:
> >
> > On 23/02/2020 17:07, Alan Cudmore wrote:
> > > I have been trying to bring up RTEMS with rtems-libbsd on the
> > > beaglebone black (latest master).
> > >
> > > I can run the regular RTEMS samples on the board, and a couple of the
> > > rtems-libbsd testsuite examples run as well.
> > >
> > > The samples such as ping01 and usb01 get a fatal exception in the
> > > function fdt_ro_probe_ , leading me to believe that maybe I am not
> > > using the correct device tree blob.
> > >
> > > I'm using the instructions here:
> > > https://git.rtems.org/rtems-docs/tree/user/bsps/arm/beagle.rst
> > >
> > > And I have am loading am335x-boneblack.dtb that I copied from a linux
> > > u-boot build. The instructions talk about getting the one from the
> > > FreeBSD repository, but there are many other files included in that
> > > dts source.
> > >
> > > What dtb is normally used for the Beaglebone black RTEMS libbsd
> testing?
> > >
> > > Is the dtb needed for the non-libbsd BSP?
> > >
> > > Also, is the ethernet supported on the RTEMS beagle BSP, or do I need
> > > libbsd to get ethernet?
> > >
> > > Thanks,
> > > Alan
> >
> > Hello Alan,
> >
> > I recommend to use the FreeBSD device trees. libbsd is FreeBSD based and
> > therefore works best with them. Normally I would suggest to use the
> > version matching the FreeBSD commit used in libbsd. But unfortunately in
> > the last commit that doesn't seem to work. Vijay had some problems with
> > it and noted that the version from FreeBSD commit
> > 19a6ceb89dbacf74697d493e48c388767126d418 works fine.
> >
> > Regarding Ethernet support: As far as I know there is no support for the
> > legacy stack. But the one in libbsd worked fine the last time I tested
> > it (which was when I ported it). If you really want to use the legacy
> > stack please note that it is still an IPv4 only one and therefore it is
> > quite limited nowadays.
> >
> > Best regards
> >
> > Christian
> _______________________________________________
> devel mailing list
> devel at rtems.org
> http://lists.rtems.org/mailman/listinfo/devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/devel/attachments/20200224/236d6998/attachment.html>