Import of the watch repository from Pebble

platform/tintin/boot/src/boot_tests.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "boot_tests.h"
+
+#include "board/board.h"
+#include "drivers/button.h"
+#include "drivers/dbgserial.h"
+#include "drivers/flash.h"
+#include "system/bootbits.h"
+#include "system/rtc_registers.h"
+#include "util/misc.h"
+
+#include "stm32f2xx.h"
+
+#include <stdint.h>
+#include <inttypes.h>
+#include <stdbool.h>
+
+static const int STUCK_BUTTON_THRESHOLD = 5;
+
+bool is_button_stuck(void) {
+  // We store how many times each button has been pressed on previous boots in this
+  // rtc backup register. Every time when we boot without that button pressed that
+  // counter gets cleared. If the byte reaches 5, return a failure.
+
+  uint32_t button_counter_register = RTC_ReadBackupRegister(STUCK_BUTTON_REGISTER);
+  uint8_t* button_counter = (uint8_t*) (&button_counter_register);
+  bool result = false;
+
+  for (int button_id = 0; button_id < NUM_BUTTONS; button_id++) {
+    if (!button_is_pressed(button_id)) {
+      button_counter[button_id] = 0;
+      continue;
+    }
+
+    if (button_counter[button_id] >= STUCK_BUTTON_THRESHOLD) {
+      dbgserial_putstr("Stuck button register is invalid, clearing.");
+      dbgserial_print_hex(button_counter_register);
+
+      RTC_WriteBackupRegister(STUCK_BUTTON_REGISTER, 0);
+      return false;
+    }
+
+    button_counter[button_id] += 1;
+
+    if (button_counter[button_id] >= STUCK_BUTTON_THRESHOLD) {
+      dbgserial_print("Button id ");
+      dbgserial_print_hex(button_id);
+      dbgserial_putstr("is stuck!");
+      result = true;
+    }
+  }
+
+  if (button_counter_register != 0) {
+    dbgserial_print("Button was pushed on boot. Button counter: ");
+    dbgserial_print_hex(button_counter_register);
+    dbgserial_newline();
+  }
+
+  RTC_WriteBackupRegister(STUCK_BUTTON_REGISTER, button_counter_register);
+  return result;
+}
+
+bool is_flash_broken(void) {
+  return !flash_sanity_check();
+}