text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2018 Scott Shawcroft for Adafruit Industries
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include "supervisor/shared/safe_mode.h"
  
  #include "mphalport.h"
  
  #if defined(MICROPY_HW_LED_STATUS) || defined(CIRCUITPY_BOOT_BUTTON)
  #include "shared-bindings/digitalio/DigitalInOut.h"
  #endif
  #include "shared-bindings/microcontroller/Processor.h"
  #include "shared-bindings/microcontroller/ResetReason.h"
  
  #include "supervisor/serial.h"
  #include "supervisor/shared/rgb_led_colors.h"
  #include "supervisor/shared/rgb_led_status.h"
  #include "supervisor/shared/translate.h"
  #include "supervisor/shared/tick.h"
  
  #define SAFE_MODE_DATA_GUARD 0xad0000af
  #define SAFE_MODE_DATA_GUARD_MASK 0xff0000ff
  
  static safe_mode_t current_safe_mode;
  
  safe_mode_t wait_for_safe_mode_reset(void) {
      uint32_t reset_state = port_get_saved_word();
      safe_mode_t safe_mode = NO_SAFE_MODE;
      if ((reset_state & SAFE_MODE_DATA_GUARD_MASK) == SAFE_MODE_DATA_GUARD) {
          safe_mode = (reset_state & ~SAFE_MODE_DATA_GUARD_MASK) >> 8;
      }
      if (safe_mode != NO_SAFE_MODE) {
          port_set_saved_word(SAFE_MODE_DATA_GUARD);
          current_safe_mode = safe_mode;
          return safe_mode;
      }
  
      const mcu_reset_reason_t reset_reason = common_hal_mcu_processor_get_reset_reason();
      if (reset_reason != RESET_REASON_POWER_ON &&
          reset_reason != RESET_REASON_RESET_PIN &&
          reset_reason != RESET_REASON_UNKNOWN) {
          return NO_SAFE_MODE;
      }
      port_set_saved_word(SAFE_MODE_DATA_GUARD | (MANUAL_SAFE_MODE << 8));
      // Wait for a while to allow for reset.
      temp_status_color(SAFE_MODE);
      #ifdef MICROPY_HW_LED_STATUS
      digitalio_digitalinout_obj_t status_led;
      common_hal_digitalio_digitalinout_construct(&status_led, MICROPY_HW_LED_STATUS);
      common_hal_digitalio_digitalinout_switch_to_output(&status_led, true, DRIVE_MODE_PUSH_PULL);
      #endif
      #ifdef CIRCUITPY_BOOT_BUTTON
      digitalio_digitalinout_obj_t boot_button;
      common_hal_digitalio_digitalinout_construct(&boot_button, CIRCUITPY_BOOT_BUTTON);
      common_hal_digitalio_digitalinout_switch_to_input(&boot_button, PULL_UP);
      #endif
      uint64_t start_ticks = supervisor_ticks_ms64();
      uint64_t diff = 0;
      while (diff < 700) {
          #ifdef MICROPY_HW_LED_STATUS
          // Blink on for 100, off for 100, on for 100, off for 100 and on for 200
          common_hal_digitalio_digitalinout_set_value(&status_led, diff > 100 && diff / 100 != 2 && diff / 100 != 4);
          #endif
          #ifdef CIRCUITPY_BOOT_BUTTON
          if (!common_hal_digitalio_digitalinout_get_value(&boot_button)) {
              return USER_SAFE_MODE;
          }
          #endif
          diff = supervisor_ticks_ms64() - start_ticks;
      }
      #ifdef MICROPY_HW_LED_STATUS
      common_hal_digitalio_digitalinout_deinit(&status_led);
      #endif
      clear_temp_status();
      port_set_saved_word(SAFE_MODE_DATA_GUARD);
      return NO_SAFE_MODE;
  }
  
  void safe_mode_on_next_reset(safe_mode_t reason) {
      port_set_saved_word(SAFE_MODE_DATA_GUARD | (reason << 8));
  }
  
  // Don't inline this so it's easy to break on it from GDB.
  void __attribute__((noinline,)) reset_into_safe_mode(safe_mode_t reason) {
      if (current_safe_mode > BROWNOUT && reason > BROWNOUT) {
          while (true) {
              // This very bad because it means running in safe mode didn't save us. Only ignore brownout
              // because it may be due to a switch bouncing.
          }
      }
  
      safe_mode_on_next_reset(reason);
      reset_cpu();
  }
  
  
  
  #define FILE_AN_ISSUE translate("\nPlease file an issue with the contents of your CIRCUITPY drive at \nhttps://github.com/adafruit/circuitpython/issues\n")
  
  void print_safe_mode_message(safe_mode_t reason) {
      if (reason == NO_SAFE_MODE) {
          return;
      }
      serial_write("\n");
  
      switch (reason) {
          case USER_SAFE_MODE:
              #ifdef BOARD_USER_SAFE_MODE_ACTION
              // Output a user safe mode string if it's set.
              serial_write_compressed(translate("You requested starting safe mode by "));
              serial_write_compressed(BOARD_USER_SAFE_MODE_ACTION);
              serial_write_compressed(translate("To exit, please reset the board without "));
              serial_write_compressed(BOARD_USER_SAFE_MODE_ACTION);
              #else
              break;
              #endif
              return;
          case MANUAL_SAFE_MODE:
              serial_write_compressed(translate("CircuitPython is in safe mode because you pressed the reset button during boot. Press again to exit safe mode.\n"));
              return;
          case PROGRAMMATIC_SAFE_MODE:
              serial_write_compressed(translate("The `microcontroller` module was used to boot into safe mode. Press reset to exit safe mode.\n"));
              return;
          default:
              break;
      }
  
      serial_write_compressed(translate("You are in safe mode: something unanticipated happened.\n"));
      switch (reason) {
          case BROWNOUT:
              serial_write_compressed(translate("The microcontroller's power dipped. Make sure your power supply provides\nenough power for the whole circuit and press reset (after ejecting CIRCUITPY).\n"));
              return;
          case HEAP_OVERWRITTEN:
              serial_write_compressed(translate("The CircuitPython heap was corrupted because the stack was too small.\nPlease increase the stack size if you know how, or if not:"));
              serial_write_compressed(FILE_AN_ISSUE);
              return;
          case NO_HEAP:
              serial_write_compressed(translate("CircuitPython was unable to allocate the heap.\n"));
              serial_write_compressed(FILE_AN_ISSUE);
              return;
          default:
              break;
      }
  
      serial_write_compressed(translate("CircuitPython core code crashed hard. Whoops!\n"));
      switch (reason) {
          case HARD_CRASH:
              serial_write_compressed(translate("Crash into the HardFault_Handler."));
              return;
          case MICROPY_NLR_JUMP_FAIL:
              serial_write_compressed(translate("NLR jump failed. Likely memory corruption."));
              return;
          case MICROPY_FATAL_ERROR:
              serial_write_compressed(translate("Fatal error."));
              break;
          case GC_ALLOC_OUTSIDE_VM:
              serial_write_compressed(translate("Attempted heap allocation when VM not running."));
              break;
              #ifdef SOFTDEVICE_PRESENT
          // defined in ports/nrf/bluetooth/bluetooth_common.mk
          // will print "Unknown reason" if somehow encountered on other ports
          case NORDIC_SOFT_DEVICE_ASSERT:
              serial_write_compressed(translate("Nordic system firmware failure assertion."));
              break;
              #endif
          case FLASH_WRITE_FAIL:
              serial_write_compressed(translate("Failed to write internal flash."));
              break;
          case MEM_MANAGE:
              serial_write_compressed(translate("Invalid memory access."));
              break;
          case WATCHDOG_RESET:
              serial_write_compressed(translate("Watchdog timer expired."));
              break;
          default:
              serial_write_compressed(translate("Unknown reason."));
              break;
      }
      serial_write_compressed(FILE_AN_ISSUE);
  }
  