test: Add tests for flash option bytes and control register

BRANCH=none
BUG=b:155897971
TEST=On dragonclaw v0.2 with Segger J-Trace and servo micro attached:
     ./test/run_device_tests.py -t flash_physical
       => PASS

Signed-off-by: Tom Hughes <tomhughes@chromium.org>
Change-Id: I9a71cdcc2947d13cf2f1d44fdbd57cf20ed6402f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2220737
Commit-Queue: Yicheng Li <yichengli@chromium.org>
Tested-by: Yicheng Li <yichengli@chromium.org>
Reviewed-by: Jett Rink <jettrink@chromium.org>

2 files changed, 99 insertions, 0 deletions

diff --git a/chip/stm32/flash-f.h b/chip/stm32/flash-f.h
index 53892655c8..8d2b8e1fae 100644
--- a/chip/stm32/flash-f.h
+++ b/chip/stm32/flash-f.h
@@ -66,6 +66,9 @@ void lock_flash_option_bytes(void);
 /**
  * Disable the flash option bytes register.
  *
+ * This function expects that bus faults have not already been ignored when
+ * called.
+ *
  * Once this function is called any attempt at accessing the flash option
  * bytes register will generate a bus fault until the next reset.
  *
@@ -76,6 +79,9 @@ void disable_flash_option_bytes(void);
 /**
  * Disable the flash control register.
  *
+ * This function expects that bus faults have not already been ignored when
+ * called.
+ *
  * Once this function is called any attempt at accessing the flash control
  * register will generate a bus fault until the next reset.
  *
diff --git a/test/flash_physical.c b/test/flash_physical.c
index 9b01445582..e5430f4bd0 100644
--- a/test/flash_physical.c
+++ b/test/flash_physical.c
@@ -3,7 +3,9 @@
  * found in the LICENSE file.
  */
 
+#include "chip/stm32/flash-f.h"
 #include "flash.h"
+#include "panic.h"
 #include "test_util.h"
 
 struct flash_info {
@@ -28,6 +30,87 @@ struct flash_info flash_info = {
 #error "Flash info not defined for this chip. Please add it."
 #endif
 
+
+test_static int test_lock_option_bytes(void)
+{
+	TEST_EQ(flash_option_bytes_locked(), true, "%d");
+
+	unlock_flash_option_bytes();
+
+	TEST_EQ(flash_option_bytes_locked(), false, "%d");
+
+	lock_flash_option_bytes();
+
+	TEST_EQ(flash_option_bytes_locked(), true, "%d");
+
+	unlock_flash_option_bytes();
+
+	TEST_EQ(flash_option_bytes_locked(), false, "%d");
+
+	return EC_SUCCESS;
+}
+
+test_static int test_disable_option_bytes(void)
+{
+	TEST_EQ(flash_option_bytes_locked(), false, "%d");
+
+	disable_flash_option_bytes();
+
+	TEST_EQ(flash_option_bytes_locked(), true, "%d");
+
+	/* Since we've disabled the option bytes we'll get a bus fault. */
+	ignore_bus_fault(1);
+
+	unlock_flash_option_bytes();
+
+	ignore_bus_fault(0);
+
+	/* Option bytes should still be locked. */
+	TEST_EQ(flash_option_bytes_locked(), true, "%d");
+
+	return EC_SUCCESS;
+}
+
+test_static int test_lock_flash_control_register(void)
+{
+	TEST_EQ(flash_control_register_locked(), true, "%d");
+
+	unlock_flash_control_register();
+
+	TEST_EQ(flash_control_register_locked(), false, "%d");
+
+	lock_flash_control_register();
+
+	TEST_EQ(flash_control_register_locked(), true, "%d");
+
+	unlock_flash_control_register();
+
+	TEST_EQ(flash_control_register_locked(), false, "%d");
+
+	return EC_SUCCESS;
+}
+
+test_static int test_disable_flash_control_register(void)
+{
+	TEST_EQ(flash_control_register_locked(), false, "%d");
+
+	disable_flash_control_register();
+
+	TEST_EQ(flash_control_register_locked(), true, "%d");
+
+	/* Since we've disabled the option bytes we'll get a bus fault. */
+	ignore_bus_fault(1);
+
+	unlock_flash_control_register();
+
+	ignore_bus_fault(0);
+
+	/* Control register should still be locked. */
+	TEST_EQ(flash_control_register_locked(), true, "%d");
+
+	return EC_SUCCESS;
+}
+
 test_static int test_flash_config(void)
 {
 	TEST_EQ(PHYSICAL_BANKS, flash_info.num_flash_banks, "%d");
@@ -40,5 +123,15 @@ void run_test(int argc, char **argv)
 {
 	ccprintf("Running flash physical test\n");
 	RUN_TEST(test_flash_config);
+	/*
+	 * TODO(b/157692395): These should be implemented for the STM32H743 as
+	 * well.
+	 */
+#if defined(CHIP_VARIANT_STM32F412)
+	RUN_TEST(test_lock_option_bytes);
+	RUN_TEST(test_disable_option_bytes);
+	RUN_TEST(test_lock_flash_control_register);
+	RUN_TEST(test_disable_flash_control_register);
+#endif
 	test_print_result();
 }