Hi Mike,
Mike Leach wrote:
Hi VIncent On Wed, 15 Jan 2025 at 09:11, V E vincent.ernst@web.de wrote:
Hi Mike, I was able to initialise the ETMs by replacing the hex phandle references with labels. For the funnels, I used "arm,coresight-funnel" like specified in the bindings of kernel 4.9, which seems to fix it. When enabling the sinks and sources via sysfs, I get the expected messages in dmesg. There are no connections folders, though. OK thats good. The connections information was added sometime in the
kernel 5.x series.
So registering the CoreSight devices seems to works, but I guess that there is only limited tracing functionality because the drivers are so old? sysfs tracing should be OK - this is no more than switching on a
source to trace into a sink and collect data.
I tried collecting the trace data via "dd if=/dev/72030000.etf of=~/trace.bin" after turning the devices on and off again, but all I get is an empty file: 0+1 records in 0+1 records out 64 bytes copied, 0.000981324 s, 65.2 kB/s Do you have an idea what I can do to fix this?
Where you may suffer is if you try to use perf. We have made a lot of enhancements and bugfixes on how perf processes trace data since 4.9
Do you know if OpenCSD is already supported for my perf version? I was able to get some perf.data, but ptm2human does not seem to work. I am not that comfortable with these tools yet, though.
Unfortunately, Nvidia's Linux for my Jetson Nano ("Linux for Tegra") only supports kernel 4.9. I guessed this might be the case There exist community solutions for getting a version 5 kernel running (on Ubuntu), but I would prefer keeping the standard Linux for Tegra if possible. What surprises me is that ...0000.etf/status (shown here [1]) does not exist on my device and I also couldn't find it in the ABI documentation. Do you have an idea what that is? This looks like a printout of many of the ETF registers in a single
sysfs file. e.g. RRP, RWP, STATUS etc. Having multiple output lines for a single sysfs file is something that the upstream maintainers frown upon so has likely been dropped. You should still be able to see the same output by reading each individual register
Yes, this is the case, thanks for the info.
Kind regards,
Vincent
Regards Mike
Best regards, Vincent [1] https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3275/index.html#pag... _______________________________________________ CoreSight mailing list -- coresight@lists.linaro.org To unsubscribe send an email to coresight-leave@lists.linaro.org --
Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK