hi Jan
have you checked your device tree file? this file is used by the kernel during boot time to know which device exists and load its respective driver. list of coresight IPs as well as their relative address map is available in "Zynq UltraScale+ Device TRM" UG1085 (v2.1) August 21, 2019 
 page 1163
B.R.
Zied Guermazi

On Friday, October 18, 2019, 05:44:30 PM GMT+2, Mathieu Poirier <mathieu.poirier@linaro.org> wrote:


Good day Jan,

Please CC the coresight mailing list when you have questions such as
this one.  There is a lot of knowledgeable people on it that are also
be able to help you.


On Fri, 18 Oct 2019 at 07:42, Jan Hoogerbrugge <jan.hoogerbrugge@nxp.com> wrote:
>
> Hi Mathieu,
>
> I am trying to understand Coresight support in the Linux kernel. I am using a Xilinx Zynq
> Ultrascale+ system. I configured the kernel with coresight support enabled. When the
> system is running I see the /sys/bus/coresight directory but the devices directory in it
> stays empty. Also, I do not see messages about coresight reported when booting:
>
> root@xilinx-zcu102-2017_4:~# ls -R /sys/bus/coresight
> /sys/bus/coresight:
> devices            drivers_autoprobe  uevent
> drivers            drivers_probe
>
> /sys/bus/coresight/devices:
>
> /sys/bus/coresight/drivers:
> root@xilinx-zcu102-2017_4:~# dmesg | grep -i coresight
> root@xilinx-zcu102-2017_4:~#
>
> Any idea what I am doing wrong?

My guess it that coresight devices for that processor have not been
specified in the device tree.  If I'm not mistaking some people (also
on this list) from Xiling have been experiencing with coresight on
that specific platform - hopefully they will chime in.

>
> I want to use Coresight to obtain some TPUI/ETM traces so that I can experiment with them.

Note that a driver for the TPIU IP block is currently not available.
I never had time to write a driver and nobody has ever submitted one.

> I hope that I can dump some traces to file so that I can process them later. Do you know about
> publicly accessible archives with traces on the Internet? This might be then an alternative
> for me.

I do not know of any.

Thanks,
Mathieu

>
> Regards,
>
> Jan
>
> --
>
> Jan Hoogerbrugge
>
> Principal Security Architect
>
> Competence Center Crypto & Security
>
> NXP Semiconductors
>
> High Tech Campus 46, 5656AE Eindhoven, The Netherlands
>
> Phone: +31 6 57728704
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