test: Add libc_printf test

BRANCH=none
BUG=b:234181908, b:254530679
TEST=./test/run_device_tests.py --board dartmonkey -t libc_printf

Signed-off-by: Tom Hughes <tomhughes@chromium.org>
Change-Id: I5ac9838dd59cb048325a27cc28d7859da040b52d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3997616
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>
Reviewed-by: Bobby Casey <bobbycasey@google.com>
Reviewed-by: Andrea Grandi <agrandi@google.com>

9 files changed, 50 insertions, 0 deletions

diff --git a/board/hatch_fp/build.mk b/board/hatch_fp/build.mk
index 8ff7ec6cfb..17e85cfb05 100644
--- a/board/hatch_fp/build.mk
+++ b/board/hatch_fp/build.mk
@@ -40,6 +40,7 @@ test-list-y=\
        flash_write_protect \
        fpsensor \
        fpsensor_hw \
+       libc_printf \
        mpu \
        mutex \
        panic \
diff --git a/board/nocturne_fp/build.mk b/board/nocturne_fp/build.mk
index cd3981263c..d91229c7e3 100644
--- a/board/nocturne_fp/build.mk
+++ b/board/nocturne_fp/build.mk
@@ -40,6 +40,7 @@ test-list-y=\
        flash_write_protect \
        fpsensor \
        fpsensor_hw \
+       libc_printf \
        mpu \
        mutex \
        panic \
diff --git a/board/nucleo-dartmonkey/build.mk b/board/nucleo-dartmonkey/build.mk
index 2e3e1f31d2..809db95260 100644
--- a/board/nucleo-dartmonkey/build.mk
+++ b/board/nucleo-dartmonkey/build.mk
@@ -22,6 +22,7 @@ test-list-y=\
        flash_write_protect \
        fpsensor \
        fpsensor_hw \
+       libc_printf \
        mpu \
        mutex \
        pingpong \
diff --git a/board/nucleo-f412zg/build.mk b/board/nucleo-f412zg/build.mk
index 21a2955bc4..37402b7e68 100644
--- a/board/nucleo-f412zg/build.mk
+++ b/board/nucleo-f412zg/build.mk
@@ -19,6 +19,7 @@ test-list-y=\
        exception \
        flash_physical \
        flash_write_protect \
+       libc_printf \
        mpu \
        mutex \
        pingpong \
diff --git a/board/nucleo-h743zi/build.mk b/board/nucleo-h743zi/build.mk
index 6153d85d8a..3a59c5d47d 100644
--- a/board/nucleo-h743zi/build.mk
+++ b/board/nucleo-h743zi/build.mk
@@ -19,6 +19,7 @@ test-list-y=\
        exception \
        flash_physical \
        flash_write_protect \
+       libc_printf \
        mpu \
        mutex \
        pingpong \
diff --git a/test/build.mk b/test/build.mk
index a4f9ee74b8..eee0e86179 100644
--- a/test/build.mk
+++ b/test/build.mk
@@ -223,6 +223,9 @@ online_calibration-y=online_calibration.o
 online_calibration_spoof-y=online_calibration_spoof.o gyro_cal_init_for_test.o
 rgb_keyboard-y=rgb_keyboard.o
 kasa-y=kasa.o
+ifeq ($(USE_BUILTIN_STDLIB), 0)
+libc_printf-y=libc_printf.o
+endif
 mpu-y=mpu.o
 mutex-y=mutex.o
 newton_fit-y=newton_fit.o
diff --git a/test/libc_printf.c b/test/libc_printf.c
new file mode 100644
index 0000000000..b3f5f03605
--- /dev/null
+++ b/test/libc_printf.c
@@ -0,0 +1,28 @@
+/* Copyright 2022 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdio.h>
+
+#include "test_util.h"
+
+test_static int test_printf(void)
+{
+	/*
+	 * The test itself is not verifying that printing works (according to
+	 * the test framework, this will always pass).
+	 *
+	 * Instead, the test runner (test/run_device_tests.py) looks for the
+	 * printed string in the test output to determine if the test passed.
+	 */
+	printf("printf called\n");
+	return EC_SUCCESS;
+}
+
+void run_test(int argc, const char **argv)
+{
+	test_reset();
+	RUN_TEST(test_printf);
+	test_print_result();
+}
diff --git a/test/libc_printf.tasklist b/test/libc_printf.tasklist
new file mode 100644
index 0000000000..959f62ef79
--- /dev/null
+++ b/test/libc_printf.tasklist
@@ -0,0 +1,9 @@
+/* Copyright 2022 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/**
+ * See CONFIG_TASK_LIST in config.h for details.
+ */
+#define CONFIG_TEST_TASK_LIST
diff --git a/test/run_device_tests.py b/test/run_device_tests.py
index 0aee1428f5..cfa034ac91 100755
--- a/test/run_device_tests.py
+++ b/test/run_device_tests.py
@@ -91,6 +91,7 @@ DATA_ACCESS_VIOLATION_20000000_REGEX = re.compile(
 DATA_ACCESS_VIOLATION_24000000_REGEX = re.compile(
     r"Data access violation, mfar = 24000000\r\n"
 )
+PRINTF_CALLED_REGEX = re.compile(r"printf called\r\n")
 
 BLOONCHIPPER = "bloonchipper"
 DARTMONKEY = "dartmonkey"
@@ -236,6 +237,10 @@ class AllTests:
                 test_args=["uart"],
             ),
             TestConfig(
+                test_name="libc_printf",
+                finish_regexes=[PRINTF_CALLED_REGEX],
+            ),
+            TestConfig(
                 config_name="mpu_ro",
                 test_name="mpu",
                 image_to_use=ImageType.RO,