test: Add scratchpad test

The first time the test runs it should pass. After rebooting, the test
should then fail because the scratchpad register is already set.

BRANCH=none
BUG=b:157059753
TEST=Build and flash bloonchipper
     On console:
     > runtest
       => PASS
     > reboot
     > runtest
       => PASS, which is WRONG
TEST=Build and flash dartmonkey
     On console:
     > runtest
       => PASS
     > reboot
     > runtest
       => FAILS, which is CORRECT

Signed-off-by: Tom Hughes <tomhughes@chromium.org>
Change-Id: I348d723d8083ecd0d9f5535785c8049f284a00b6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2209189
Commit-Queue: Abe Levkoy <alevkoy@chromium.org>
Reviewed-by: Abe Levkoy <alevkoy@chromium.org>

board/hatch_fp/build.mk

@@ -21,6 +21,7 @@ test-list-y=\
        rollback \
        rollback_entropy \
        rtc \
+       scratchpad \
        sha256 \
        sha256_unrolled \
        stm32f_rtc \

board/nocturne_fp/build.mk

@@ -22,6 +22,7 @@ test-list-y=\
        rollback \
        rollback_entropy \
        rtc \
+       scratchpad \
        sha256 \
        sha256_unrolled \
        stm32f_rtc \

board/nucleo-f412zg/build.mk

@@ -19,6 +19,7 @@ test-list-y=\
        rollback \
        rollback_entropy \
        rtc \
+       scratchpad \
        sha256 \
        sha256_unrolled \
        stm32f_rtc \

board/nucleo-h743zi/build.mk

@@ -19,5 +19,6 @@ test-list-y=\
        rollback \
        rollback_entropy \
        rtc \
+       scratchpad \
        sha256 \
        sha256_unrolled \

test/build.mk

@@ -163,6 +163,7 @@ rollback_entropy-y=rollback_entropy.o
 rsa-y=rsa.o
 rsa3-y=rsa.o
 rtc-y=rtc.o
+scratchpad-y=scratchpad.o
 sbs_charging-y=sbs_charging.o
 sbs_charging_v2-y=sbs_charging_v2.o
 sha256-y=sha256.o

test/scratchpad.c

@@ -0,0 +1,34 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "system.h"
+#include "test_util.h"
+
+/**
+ * The first time this test runs, it should pass. After rebooting, the test
+ * should fail because the scratchpad register is set to 1.
+ */
+test_static int test_scratchpad(void)
+{
+	int rv;
+	uint32_t scratch;
+
+	scratch = system_get_scratchpad();
+	TEST_EQ(scratch, 0, "%d");
+
+	rv = system_set_scratchpad(1);
+	TEST_EQ(rv, EC_SUCCESS, "%d");
+
+	scratch = system_get_scratchpad();
+	TEST_EQ(scratch, 1, "%d");
+
+	return EC_SUCCESS;
+}
+
+void run_test(void)
+{
+	RUN_TEST(test_scratchpad);
+	test_print_result();
+}

test/scratchpad.tasklist

@@ -0,0 +1,9 @@
+/* Copyright 2020 The Chromium OS Authors. All rights reserved.
+ * 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  /* no tasks */