test(panic_handler): Added unit test to verify panic handler can halt

This test verifies that the panic handler can indeed halt when
configured to print and halt instead of rebboting.

tools/test_apps/system/panic/main/include/test_panic.h

@@ -83,6 +83,10 @@ void test_setup_coredump_summary(void);
 void test_coredump_summary(void);
 #endif
 
+#if CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT
+void test_panic_halt(void);
+#endif /* CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT */
+
 #ifdef __cplusplus
 }
 #endif

tools/test_apps/system/panic/main/test_app_main.c

@@ -127,6 +127,9 @@ void app_main(void)
     HANDLE_TEST(test_name, test_tcb_corrupted);
     HANDLE_TEST(test_name, test_panic_handler_stuck0);
     HANDLE_TEST(test_name, test_panic_handler_crash0);
+#if CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT
+    HANDLE_TEST(test_name, test_panic_halt);
+#endif /* CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT */
 #if CONFIG_ESP_COREDUMP_ENABLE_TO_FLASH && CONFIG_ESP_COREDUMP_DATA_FORMAT_ELF
     HANDLE_TEST(test_name, test_setup_coredump_summary);
     HANDLE_TEST(test_name, test_coredump_summary);

tools/test_apps/system/panic/main/test_panic.c

@@ -443,3 +443,12 @@ void test_capture_dram(void)
     assert(0);
 }
 #endif
+
+#if CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT
+void test_panic_halt(void)
+{
+    printf("Triggering panic. Device should print 'CPU halted.' and stop.\n");
+    fflush(stdout);
+    assert(0);
+}
+#endif /* CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT */

tools/test_apps/system/panic/pytest_panic.py

@@ -1223,3 +1223,12 @@ def test_tcb_corrupted(dut: PanicTestDut, target: str, config: str, test_func_na
         expected_backtrace=None,
         expected_coredump=coredump_pattern
     )
+
+
+@pytest.mark.generic
+@pytest.mark.supported_targets
+@pytest.mark.parametrize('config', ['panic_halt'], indirect=True)
+def test_panic_halt(dut: PanicTestDut) -> None:
+    dut.run_test_func('test_panic_halt')
+    dut.expect_exact('CPU halted.', timeout=30)
+    dut.expect_none(dut.REBOOT, timeout=3)

tools/test_apps/system/panic/sdkconfig.ci.panic_halt

@@ -0,0 +1,5 @@
+# Panic halt CI config
+CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT=y
+CONFIG_ESP_SYSTEM_PANIC_PRINT_REBOOT=n
+CONFIG_ESP_SYSTEM_PANIC_SILENT_REBOOT=n
+CONFIG_ESP_SYSTEM_PANIC_GDBSTUB=n