Jetson Orin Nano CoreSight ETM enabled in kernel but /sys/bus/coresight/devices is empty

Robotics & Edge Computing Jetson Systems Jetson Orin Nano
1

Hi NVIDIA team,

I am trying to enable ARM CoreSight ETM tracing on Jetson Orin Nano (T234), but I cannot bring up any CoreSight devices even after rebuilding the kernel with CoreSight options enabled.

Environment

  • Board: Jetson Orin Nano Devkit
  • SoC: T234
  • JetPack/L4T: JetPack 6 / R36.4.3
  • Kernel: 5.15.148-tegra

What I changed

I rebuilt the kernel and enabled:

  • CONFIG_CORESIGHT=y
  • CONFIG_CORESIGHT_LINKS_AND_SINKS=y
  • CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y
  • CONFIG_CORESIGHT_SOURCE_ETM4X=y

I replaced kernel image + DTB and rebooted successfully.

Reproduction / Current status

zcat /proc/config.gz | grep CORESIGHT

Output:

CONFIG_CORESIGHT=y
CONFIG_CORESIGHT_LINKS_AND_SINKS=y
CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y
CONFIG_CORESIGHT_SINK_TPIU=y
CONFIG_CORESIGHT_SINK_ETBV10=y
CONFIG_CORESIGHT_SOURCE_ETM4X=y

ls -la /sys/bus/coresight/devices

Output:

total 0
drwxr-xr-x 2 root root 0 ...
drwxr-xr-x 4 root root 0 ...

sudo dmesg | grep -i coresight

Output:

[    ...] cs_system_cfg: CoreSight Configuration manager initialised

Also, decompiling the running DTB does not show coresight/etm/tmc/funnel/replicator nodes.

My understanding

This no longer looks like a kernel Kconfig issue.
It seems T234 CoreSight DT/platform description is missing in my current source/release.

I saw forum comments mentioning:
hardware/nvidia/soc/t23x/kernel-dts/tegra234-soc/tegra234-soc-coresight.dtsi
but I cannot find a usable public file/patch for this on my side.

Request

Could you please provide one of the following for R36.4.3 (or the nearest supported release):

  1. A working tegra234-soc-coresight.dtsi; or
  2. A patch set (DTS/DTSI + dependencies) that can be applied directly; or
  3. A clear statement that ETM is not supported on this release, and recommended alternatives.

If supported, please share:

  • ETM/TMC/Funnel/Replicator MMIO addresses
  • required clock/reset bindings
  • ports/endpoints topology
  • expected validation output (/sys/bus/coresight/devices node list)

Thanks in advance.

References

4

Hi,
Please get the file from

Jetson Linux | NVIDIA Developer
Driver Package (BSP) Sources
/hardware/nvidia/soc/t23x/kernel-dts/tegra234-soc/tegra234-soc-coresight.dtsi

It shall be eligible for Jetpack 6. Please give it a try.

5

Thanks for sharing the tegra234-soc-coresight.dtsi path.
I tested it on JetPack 6 (R36.4.3), but ETM/TMC still do not bind successfully.

Environment

  • Board: Jetson Orin Nano Devkit (T234)
  • JetPack/L4T: R36.4.3
  • Kernel: 5.15.148-tegra

What I did

  1. Found file in R35.6.4 public_sources.tbz2:
    hardware/nvidia/soc/t23x/kernel-dts/tegra234-soc/tegra234-soc-coresight.dtsi
  2. Ported this dtsi into my R36.4.3 source tree and included it in board DT chain.
  3. Adjusted obvious compatibility issues for R36 (clock provider/cpu phandle mapping).
  4. Rebuilt DTBs, deployed DTB, updated initrd, rebooted.

Current result

  • Kernel config is enabled:
    • CONFIG_CORESIGHT=y
    • CONFIG_CORESIGHT_LINKS_AND_SINKS=y
    • CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y
    • CONFIG_CORESIGHT_SOURCE_ETM4X=y
  • Boot log shows only:
    • cs_system_cfg: CoreSight Configuration manager initialised
  • No ETM/TMC probe success logs.
  • Driver directories show no bound devices:
    • /sys/bus/amba/drivers/coresight-etm4x → only uevent
    • /sys/bus/amba/drivers/coresight-tmc → only uevent

Request

Could you please provide a known-good patch/config for R36.x (preferably R36.4.3 or nearest) including:

  1. Exact tegra234 CoreSight DTS/DTSI content for this release,
  2. Required clock/reset/power/security settings,
  3. Any additional kernel args or runtime setup needed to make ETM/TMC bind.

If possible, please share expected success logs and expected /sys/bus/coresight/devices node list for Orin Nano.

Thanks a lot.

7

Hi,
We have tested it on AGX Orin developer kit:
Are there any processor tracing support on Jetson AGX Orin - #9 by WayneWWW

Will check with the teams and see if it works the same on Orin Nano.

8

Thanks for your help! We are looking forward to your team’s feedback on whether the Orin Nano supports the same tracing features. Hope to hear from you soon.

9

## Jetson Orin Nano: ETM trace not producing payload (only 64-byte AUXTRACE)

I’m trying to collect ETM control-flow trace with `perf` on Jetson Orin Nano, but I cannot get valid ETM payload.
Below is the current status and reproduction details.

1) Device/PMU enumeration status

CoreSight devices currently visible under `/sys/bus/coresight/devices`:

  • `etm0 … etm5`
  • `funnel0 … funnel4`
  • `replicator0`
  • `tmc_etf0`

Perf side:

  • `perf list | grep -i cs_etm` shows `cs_etm//`
  • `/sys/bus/event_source/devices/cs_etm` exists

2) Key boot/runtime errors

Boot log contains:

  • `coresight-tmc: probe of 24070000.etr failed with error -13`

CBB errors also appear:

  • `Error:cbb-fabric, Errmon:2`
  • `Error Code: SLAVE_ERR`
  • `MASTER_ID: CCPLEX`
  • `Protection: Unprivileged, Non-Secure, Data Access`
  • Example fault addresses: `0x27840fe0 / 0x27940fe0 / 0x27a40fe0 / 0x27b40fe0`

3) ETM register status (example)

  • `trcauthstatus = 0x88`
  • `trcoslsr = 0xa`
  • `trcpdsr = 0x23` (on some cores)

I’m not sure whether `0x88` means non-secure ETM debug/trace is disabled on this platform.

4) Reproduction setup

Since ETR is unavailable, I disabled ETR in DTB and tried to sink ETM to ETF.

Commands:

```bash
sudo perf record -vv -o perf.data -e cs_etm// -C 0 – timeout 3s taskset -c 0 ./branch_demo
sudo perf report -D -i perf.data | rg “CoreSight ETM Trace data|AUXTRACE|SAMPLE events” -n
```

5) Observed result

Results are consistently:

  • `PERF_RECORD_AUXTRACE_INFO` exists
  • `PERF_RECORD_AUXTRACE` exists
  • but `CoreSight ETM Trace data: size 64 bytes`
  • `SAMPLE events: 0`
  • `perf script --itrace=…` has no output

So there is AUXTRACE metadata/header, but almost no valid ETM payload.

6) Question

Does `trcauthstatus = 0x88` on Orin Nano mean non-secure ETM trace is unavailable by default?
If yes, what is the official way to enable ETM trace so that real ETM payload can be collected?