tests: subsys: swo: Add test that checks SWO log backend

CODEOWNERS

@@ -941,6 +941,7 @@
 /tests/subsys/partition_manager/region/   @nordicjm @tejlmand
 /tests/subsys/partition_manager/static_pm_file/ @nordicjm @tejlmand
 /tests/subsys/pcd/                        @nrfconnect/ncs-pluto
+/tests/subsys/swo/                        @nrfconnect/ncs-low-level-test
 /tests/subsys/usb/negotiated_speed/       @nrfconnect/ncs-low-level-test
 /tests/subsys/ipc/                        @nrfconnect/ncs-low-level-test
 /tests/tfm/                               @nrfconnect/ncs-aegir @magnev

scripts/ci/tags.yaml

@@ -1916,3 +1916,7 @@ ci_samples_nrf54h20:
     - nrf/samples/nrf54h20/
     - zephyr/modules/hal_nordic/
     - zephyr/soc/nordic/nrf54h/
+
+ci_tests_subsys_swo:
+  files:
+    - nrf/tests/subsys/swo/

tests/subsys/swo/CMakeLists.txt

@@ -0,0 +1,13 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(log_swo)
+
+FILE(GLOB app_sources src/main.c)
+target_sources(app PRIVATE ${app_sources})

tests/subsys/swo/prj.conf

@@ -0,0 +1,2 @@
+CONFIG_LOG=y
+CONFIG_LOG_BACKEND_SWO=y

tests/subsys/swo/pytest/test_swo.py

@@ -0,0 +1,131 @@
+#
+# Copyright (c) 2025 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+import logging
+import re
+import subprocess
+from pathlib import Path
+import time
+
+import psutil
+from twister_harness import DeviceAdapter
+
+logger = logging.getLogger(__name__)
+
+# Kill parent process and all child processes (if started)
+def _kill(proc):
+    try:
+        for child in psutil.Process(proc.pid).children(recursive=True):
+            child.kill()
+        proc.kill()
+    except Exception as e:
+        logger.exception(f'Could not kill nrfutil - {e}')
+
+
+def test_swo_logging(dut: DeviceAdapter):
+    """
+    Compile and flash test application on MCU.
+    Tested core(s) uses SWO backend for logging.
+    JLinkSWOViewerCLExe is used to collect logs.
+    """
+    BUILD_DIR = str(dut.device_config.build_dir)
+    PLATFORM = dut.device_config.platform
+    SEGGER_ID = dut.device_config.id
+    COLLECT_TIMEOUT = 10.0
+    EXPECTED = rf"\d+: Hello from {PLATFORM}"
+
+    logger.debug(f"{dut.device_config=}")
+
+    SWO_CONFIG = {
+        'nrf52dk/nrf52832': {
+            'device': 'nRF52832_xxAA',
+            'cpufreq': 64000000,
+            'swofreq': 1000000,
+        },
+        'nrf52840dk/nrf52840': {
+            'device': 'nRF52840_xxAA',
+            'cpufreq': 64000000,
+            'swofreq': 1000000,
+        },
+        'nrf5340dk/nrf5340/cpuapp': {
+            'device': 'nRF5340_xxAA_APP',
+            'cpufreq': 64000000,
+            'swofreq': 1000000,
+        },
+        'nrf54l15dk/nrf54l05/cpuapp': {
+            'device': 'nRF54L05_M33',
+            'cpufreq': 128000000,
+            'swofreq': 1000000,
+        },
+        'nrf54l15dk/nrf54l10/cpuapp': {
+            'device': 'nRF54L10_M33',
+            'cpufreq': 128000000,
+            'swofreq': 1000000,
+        },
+        'nrf54l15dk/nrf54l15/cpuapp': {
+            'device': 'nRF54L15_M33',
+            'cpufreq': 128000000,
+            'swofreq': 1000000,
+        },
+        'nrf54lm20dk/nrf54lm20a/cpuapp': {
+            'device': 'NRF54LM20A_M33',
+            'cpufreq': 128000000,
+            'swofreq': 1000000,
+        },
+        'nrf54lv10dk/nrf54lv10a/cpuapp': {
+            'device': 'NRF54LV10A_M33',
+            'cpufreq': 128000000,
+            'swofreq': 1000000,
+        },
+    }
+
+    log_filename = f"{BUILD_DIR}/log_swo.txt"
+    try:
+        Path(f"{log_filename}").unlink()
+        logger.info("Old output file was deleted")
+    except FileNotFoundError:
+        pass
+
+    # Wait a bit for the core to boot
+    time.sleep(2)
+
+    # use JLinkSWOViewerCLExe to collect logs
+    cmd = f"JLinkSWOViewerCLExe -USB {SEGGER_ID}"
+    cmd += f" -device {SWO_CONFIG[PLATFORM]['device']}"
+    cmd += f" -cpufreq {SWO_CONFIG[PLATFORM]['cpufreq']}"
+    cmd += f" -swofreq {SWO_CONFIG[PLATFORM]['swofreq']}"
+    cmd += f" -itmmask 0xFFFF -outputfile {log_filename}"
+    try:
+        logger.info(f"Executing:\n{cmd}")
+        proc = subprocess.Popen(
+            cmd,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.STDOUT,
+            encoding='UTF-8',
+            shell=True,
+        )
+    except OSError as exc:
+        logger.error(f"Unable to start JLinkSWOViewerCLExe:\n{cmd=}\n{exc=}")
+
+    try:
+        proc.wait(COLLECT_TIMEOUT)
+    except subprocess.TimeoutExpired:
+        pass
+    finally:
+        _kill(proc)
+
+    # read logs
+    with open(f"{log_filename}", errors="ignore") as log_file:
+        log_file_content = log_file.read()
+
+    # if nothing in log_file, stop test
+    assert(
+        len(log_file_content) > 0
+    ), f"File {log_filename} is empty"
+
+    # Check if log file contains expected string
+    expected_str = re.search(EXPECTED, log_file_content)
+    assert expected_str is not None, f"Failed to match {EXPECTED} in {log_filename}"

tests/subsys/swo/src/main.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2025 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(log_swo, LOG_LEVEL_INF);
+
+#include <zephyr/kernel.h>
+
+int main(void)
+{
+	int counter = 1;
+
+	while (true) {
+		LOG_INF("%d: Hello from %s", counter, CONFIG_BOARD_TARGET);
+		counter++;
+		k_msleep(1000);
+	}
+}

tests/subsys/swo/testcase.yaml

@@ -0,0 +1,20 @@
+tests:
+  swo.logging:
+    tags: ci_tests_subsys_swo
+    harness: pytest
+    harness_config:
+      pytest_dut_scope: session
+      pytest_root:
+        - "pytest/test_swo.py::test_swo_logging"
+    timeout: 30
+    platform_allow:
+      - nrf52dk/nrf52832
+      - nrf52840dk/nrf52840
+      - nrf5340dk/nrf5340/cpuapp
+      - nrf54l15dk/nrf54l05/cpuapp
+      - nrf54l15dk/nrf54l10/cpuapp
+      - nrf54l15dk/nrf54l15/cpuapp
+      - nrf54lm20dk/nrf54lm20a/cpuapp
+      - nrf54lv10dk/nrf54lv10a/cpuapp
+    integration_platforms:
+      - nrf5340dk/nrf5340/cpuapp