efi_selftest: unit test for GetTime()

Provide a unit test for the GetTime() runtime service.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_selftest/efi_selftest_rtc.c b/lib/efi_selftest/efi_selftest_rtc.c
new file mode 100644
index 0000000..8d440dc
--- /dev/null
+++ b/lib/efi_selftest/efi_selftest_rtc.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * efi_selftest_rtc
+ *
+ * Copyright (c) 2018 Heinrich Schuchardt <xypron.glpk@gmx.de>
+ *
+ * Test the real time clock runtime services.
+ */
+
+#include <efi_selftest.h>
+
+#define EFI_ST_NO_RTC "Could not read real time clock\n"
+
+static struct efi_runtime_services *runtime;
+
+/*
+ * Setup unit test.
+ *
+ * @handle:	handle of the loaded image
+ * @systable:	system table
+ * @return:	EFI_ST_SUCCESS for success
+ */
+static int setup(const efi_handle_t handle,
+		 const struct efi_system_table *systable)
+{
+	runtime = systable->runtime;
+	return EFI_ST_SUCCESS;
+}
+
+/*
+ * Execute unit test.
+ *
+ * Display current time.
+ *
+ * @return:	EFI_ST_SUCCESS for success
+ */
+static int execute(void)
+{
+	efi_status_t ret;
+	struct efi_time tm;
+
+	/* Display current time */
+	ret = runtime->get_time(&tm, NULL);
+	if (ret != EFI_SUCCESS) {
+#ifdef CONFIG_CMD_DATE
+		efi_st_error(EFI_ST_NO_RTC);
+		return EFI_ST_FAILURE;
+#else
+		efi_st_todo(EFI_ST_NO_RTC);
+		return EFI_ST_SUCCESS;
+#endif
+	} else {
+		efi_st_printf("Time according to real time clock: "
+			      "%.4u-%.2u-%.2u %.2u:%.2u:%.2u\n",
+			      tm.year, tm.month, tm.day,
+			      tm.hour, tm.minute, tm.second);
+	}
+
+	return EFI_ST_SUCCESS;
+}
+
+EFI_UNIT_TEST(rtc) = {
+	.name = "real time clock",
+	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
+	.setup = setup,
+	.execute = execute,
+};