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

Robotics & Edge Computing Jetson Systems Jetson Orin Nano
13

Hi @1209762583 .

Please refer below steps:

Host Side (Ubuntu)
  1. Sync the L4T source tree for the target Jetson release:
cd Linux_for_Tegra/source
./source_sync.sh -t jetson_36.4.3
  1. Apply the CoreSight kernel patch to enable trace support:
cd Linux_for_Tegra/source/kernel/kernel-jammy-src
git apply coresight.patch
  1. Apply the device-tree overlay patch for CoreSight nodes:
cd Linux_for_Tegra/source/hardware/nvidia/t23x/nv-public
git apply overlay.patch

  1. Drop in the CoreSight SoC device-tree include:

    • Add tegra234-soc-coresight.dtsi into Linux_for_Tegra/source/hardware/nvidia/t23x/nv-public/nv-soc/.

  2. Build the Jetson Linux Kernel, NVIDIA Out-of-Tree Modules, and DTBs by following the Kernel Customization guide.

  3. Enable non-secure debug access in BCT (slot B) by editing Linux_for_Tegra/bootloader/generic/BCT/tegra234-br-bct_b-p3767-0000-l4t.dts:

-        SecureDebugControlNoneEcid = <0x0>;
+        SecureDebugControlNoneEcid = <0x10>;
  1. Apply the same BCT change to the primary slot in Linux_for_Tegra/bootloader/generic/BCT/tegra234-br-bct-p3767-0000-l4t.dts:
-        SecureDebugControlNoneEcid = <0x0>;
+        SecureDebugControlNoneEcid = <0x10>;
  1. Flash the device
Target Device (Jetson Orin Nano)
  1. Ensure the running kernel is built with CoreSight enabled. Verify options (example from a working build):
$ zgrep CORESIGHT /proc/config.gz

CONFIG_CORESIGHT=y
CONFIG_CORESIGHT_LINKS_AND_SINKS=y
CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y
# CONFIG_CORESIGHT_CATU is not set
# CONFIG_CORESIGHT_SINK_TPIU is not set
# CONFIG_CORESIGHT_SINK_ETBV10 is not set
CONFIG_CORESIGHT_SOURCE_ETM4X=y
CONFIG_CORESIGHT_STM=y
# CONFIG_CORESIGHT_CPU_DEBUG is not set
# CONFIG_CORESIGHT_CTI is not set
# CONFIG_CORESIGHT_TRBE is not set
  1. Confirm CoreSight devices are exposed under sysfs:
$ ls /sys/bus/coresight/devices

etm0  etm1  etm2  etm3  etm4  etm5  funnel0  funnel1  funnel2  funnel3  funnel4  stm0  tmc_etf0
  1. Follow the forum topic to build perf with the CoreSight Embedded Trace Extension.
  2. Run a minimal perf trace test (adjust CPU and sink name to match your system):
sudo perf record -m 32768 -o perf.data -e cs_etm/@tmc_etf0/ -C 0 -- taskset -c 0 sleep 1
sudo perf report -D -i perf.data

Thanks

coresight.patch (1.2 KB)
overlay.patch (1.1 KB)
tegra234-soc-coresight.dtsi (11.2 KB)