test: Add rollback unit test

This test only runs on device and requires manual verification that a
memory access violation occurred.

Note that bloonchipper region 1 on dragonclaw fails as indicated in
tests below.

BRANCH=none
BUG=b:155229277, b:151105339
TEST=Compile and flash bloonchipper on dragonclaw with region 0
     "runtest" on console
     => Reboots with "Data access violation, mfar = 8020000"
        => PASS
TEST=Compile and flash bloonchipper on dragonclaw with region 1
     "runtest" on console
     => Memory is successfully read
        => FAIL
TEST=Compile and flash dartmonkey on dragontalon with region 0
     "runtest" on console
     => Reboots with "Data access violation, mfar = 80c0000"
        => PASS
TEST=Compile and flash dartmonkey on dragontalon with region 1
     "runtest" on console
     => Reboots with "Data access violation, mfar = 80e0000"
        => PASS

Signed-off-by: Tom Hughes <tomhughes@chromium.org>
Change-Id: I3e9cc568a0b16c6091d96c4373798fe4de4ab65b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2190829
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>

board/hatch_fp/build.mk

@@ -17,6 +17,7 @@ test-list-y=\
        crc32 \
        mutex \
        pingpong \
+       rollback \
        rtc \
        sha256 \
        sha256_unrolled \

board/nocturne_fp/build.mk

@@ -18,6 +18,7 @@ test-list-y=\
        crc32 \
        mutex \
        pingpong \
+       rollback \
        rtc \
        sha256 \
        sha256_unrolled \

board/nucleo-f412zg/build.mk

@@ -15,6 +15,7 @@ test-list-y=\
        crc32 \
        mutex \
        pingpong \
+       rollback \
        rtc \
        sha256 \
        sha256_unrolled \

board/nucleo-h743zi/build.mk

@@ -15,6 +15,7 @@ test-list-y=\
        crc32 \
        mutex \
        pingpong \
+       rollback \
        rtc \
        sha256 \
        sha256_unrolled \

test/build.mk

@@ -157,6 +157,7 @@ power_button-y=power_button.o
 powerdemo-y=powerdemo.o
 printf-y=printf.o
 queue-y=queue.o
+rollback-y=rollback.o
 rsa-y=rsa.o
 rsa3-y=rsa.o
 rtc-y=rtc.o

test/rollback.c

@@ -0,0 +1,121 @@
+/* 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 <stdbool.h>
+#include "flash.h"
+#include "mpu.h"
+#include "test_util.h"
+
+struct rollback_info {
+	int region_0_offset;
+	int region_1_offset;
+	uint32_t region_size_bytes;
+};
+
+/* These values are intentionally hardcoded here instead of using the chip
+ * config headers, so that if the headers are accidentally changed we can catch
+ * it.
+ */
+#if defined(CHIP_VARIANT_STM32F412)
+struct rollback_info rollback_info = {
+	.region_0_offset = 0x20000,
+	.region_1_offset = 0x40000,
+	.region_size_bytes = 128 * 1024,
+};
+#elif defined(CHIP_VARIANT_STM32H7X3)
+struct rollback_info rollback_info = {
+	.region_0_offset = 0xC0000,
+	.region_1_offset = 0xE0000,
+	.region_size_bytes = 128 * 1024,
+};
+#else
+#error "Rollback info not defined for this chip. Please add it."
+#endif
+
+test_static int read_rollback_region(const struct rollback_info *info,
+				     int region)
+{
+	int i;
+	char data;
+	uint32_t bytes_read = 0;
+
+	int offset = region == 0 ? info->region_0_offset :
+				   info->region_1_offset;
+
+	for (i = 0; i < info->region_size_bytes; i++) {
+		if (flash_read(offset + i, sizeof(data), &data) == EC_SUCCESS)
+			bytes_read++;
+	}
+
+	return bytes_read;
+}
+
+test_static int _test_lock_rollback(const struct rollback_info *info,
+				    int region)
+{
+	int rv;
+
+	mpu_enable();
+
+	rv = mpu_lock_rollback(0);
+	TEST_EQ(rv, EC_SUCCESS, "%d");
+
+	/* unlocked we should be able to read both regions */
+	rv = read_rollback_region(info, 0);
+	TEST_EQ(rv, rollback_info.region_size_bytes, "%d");
+
+	rv = read_rollback_region(info, 1);
+	TEST_EQ(rv, rollback_info.region_size_bytes, "%d");
+
+	rv = mpu_lock_rollback(1);
+	TEST_EQ(rv, EC_SUCCESS, "%d");
+
+	/* TODO(b/156112448): Validate that it actually reboots with the correct
+	 * data access violation.
+	 */
+	read_rollback_region(info, region);
+
+	/* Should not get here. Should reboot with:
+	 *
+	 * Data access violation, mfar = XXX
+	 *
+	 * where XXX = start of rollback
+	 */
+	TEST_ASSERT(false);
+
+	return EC_ERROR_UNKNOWN;
+}
+
+test_static int test_lock_rollback_region_0(void)
+{
+	return _test_lock_rollback(&rollback_info, 0);
+}
+
+test_static int test_lock_rollback_region_1(void)
+{
+	return _test_lock_rollback(&rollback_info, 1);
+}
+
+test_static int test_lock_rollback(void)
+{
+	/* This call should never return due to panic.
+	 * TODO(b/156112448): For now you have to manually test each region
+	 * by itself.
+	 */
+	test_lock_rollback_region_0();
+
+#if 0
+	test_lock_rollback_region_1();
+#endif
+
+	return EC_ERROR_UNKNOWN;
+}
+
+void run_test(void)
+{
+	ccprintf("Running rollback test\n");
+	RUN_TEST(test_lock_rollback);
+	test_print_result();
+}

test/rollback.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 */