efi_selftest: add a test for ResetSystem()

The unit test will reset the system by calling the ResetSystem() runtime
service before or after ExitBootServices() according to the users choice
by setting environment variable efi_selftest to:

* 'reset system' or
* 'reset system runtime'.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

lib/efi_selftest/Makefile

@@ -31,6 +31,7 @@ efi_selftest_mem.o \
 efi_selftest_memory.o \
 efi_selftest_open_protocol.o \
 efi_selftest_register_notify.o \
+efi_selftest_reset.o \
 efi_selftest_set_virtual_address_map.o \
 efi_selftest_textinput.o \
 efi_selftest_textinputex.o \

lib/efi_selftest/efi_selftest_reset.c

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * efi_selftest_reset
+ *
+ * Copyright (c) 2020 Heinrich Schuchardt <xypron.glpk@gmx.de>
+ *
+ * This test checks the following service at boot time or runtime:
+ * ResetSystem()
+ */
+
+#include <efi_selftest.h>
+
+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.
+ *
+ * @return:	EFI_ST_SUCCESS for success
+ */
+static int execute(void)
+{
+	u16 reset_data[] = L"Reset by selftest";
+
+	runtime->reset_system(EFI_RESET_COLD, EFI_SUCCESS,
+			      sizeof(reset_data), reset_data);
+	efi_st_error("Reset failed.\n");
+	return EFI_ST_FAILURE;
+}
+
+EFI_UNIT_TEST(reset) = {
+	.name = "reset system",
+	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
+	.setup = setup,
+	.execute = execute,
+	.on_request = true,
+};
+
+EFI_UNIT_TEST(resetrt) = {
+	.name = "reset system runtime",
+	.phase = EFI_SETUP_BEFORE_BOOTTIME_EXIT,
+	.setup = setup,
+	.execute = execute,
+	.on_request = true,
+};