libpayload: Add unit-tests framework and first test case

This commit adds a unit-tests framework ported from coreboot, and test
for drivers/speaker. Usage of the unit-tests framework is same as for
the coreboot one.

Change-Id: Iaa94ee4dcdc3f74af830113813df0e8fb0b31e4f
Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58242
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Yu-Ping Wu <yupingso@google.com>

payloads/libpayload/tests/include/tests/test.h

@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _TESTS_TEST_H
+#define _TESTS_TEST_H
+
+/*
+ * Standard test header that should be included in all tests. For now it just encapsulates the
+ * include dependencies for Cmocka. Test-specific APIs that are so generic we would want them
+ * available everywhere could also be added here.
+ */
+
+#include <arch/types.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <setjmp.h>
+#include <cmocka.h>
+
+/* Helper macro to aviud checkpatch errors for some macros */
+#define EMPTY_WRAP(...) __VA_ARGS__
+
+/*
+ * Set symbol value and make it global.
+ */
+#define TEST_SYMBOL(symbol, value) asm(".set " #symbol ", " #value "\n\t.globl " #symbol)
+
+/*
+ * Define memory region for testing purpose.
+ *
+ * Create buffer with specified name and size.
+ * Create end symbol for it.
+ */
+#define TEST_REGION(region, size) uint8_t _##region[size];                                     \
+	TEST_SYMBOL(_e##region, _##region + size);                                             \
+	TEST_SYMBOL(_##region##_size, size)
+
+/*
+ * Set start, end and size symbols describing region without allocating memory for it.
+ */
+#define TEST_REGION_UNALLOCATED(region, start, size) EMPTY_WRAP(                               \
+	TEST_SYMBOL(_##region, start);                                                         \
+	TEST_SYMBOL(_e##region, _##region + size);                                             \
+	TEST_SYMBOL(_##region##_size, size)                                                    \
+)
+
+/* Wrapper for running cmocka test groups using name provided by build system in __TEST_NAME__
+   This should be used instead of cmocka_run_group_tests(). If there is a need to use custom
+   group name, then please use cmocka_run_group_tests_name(). */
+#define lp_run_group_tests(group_tests, group_setup, group_teardown)                           \
+	cmocka_run_group_tests_name((__TEST_NAME__ "(" #group_tests ")"), group_tests,         \
+				    group_setup, group_teardown)
+
+#endif /* _TESTS_TEST_H */