/**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */
#ifdef __AVR__

#include "../../inc/MarlinConfig.h"
#include "HAL.h"

#ifdef USBCON
  DefaultSerial1 MSerial0(false, Serial);
  #ifdef BLUETOOTH
    BTSerial btSerial(false, bluetoothSerial);
  #endif
#endif

// ------------------------
// Public Variables
// ------------------------

// Don't initialize/override variable (which would happen in .init4)
uint8_t reset_reason __attribute__((section(".noinit")));

// ------------------------
// Public functions
// ------------------------

__attribute__((naked))             // Don't output function pro- and epilogue
__attribute__((used))              // Output the function, even if "not used"
__attribute__((section(".init3"))) // Put in an early user definable section
void HAL_save_reset_reason() {
  #if ENABLED(OPTIBOOT_RESET_REASON)
    __asm__ __volatile__(
      A("STS %0, r2")
      : "=m"(reset_reason)
    );
  #else
    reset_reason = MCUSR;
  #endif

  // Clear within 16ms since WDRF bit enables a 16ms watchdog timer -> Boot loop
  MCUSR = 0;
  wdt_disable();
}

void HAL_init() {
  // Init Servo Pins
  #define INIT_SERVO(N) OUT_WRITE(SERVO##N##_PIN, LOW)
  #if HAS_SERVO_0
    INIT_SERVO(0);
  #endif
  #if HAS_SERVO_1
    INIT_SERVO(1);
  #endif
  #if HAS_SERVO_2
    INIT_SERVO(2);
  #endif
  #if HAS_SERVO_3
    INIT_SERVO(3);
  #endif
}

void HAL_reboot() {
  #if ENABLED(USE_WATCHDOG)
    while (1) { /* run out the watchdog */ }
  #else
    void (*resetFunc)() = 0;  // Declare resetFunc() at address 0
    resetFunc();              // Jump to address 0
  #endif
}

#if ENABLED(SDSUPPORT)

  #include "../../sd/SdFatUtil.h"
  int freeMemory() { return SdFatUtil::FreeRam(); }

#else // !SDSUPPORT

extern "C" {
  extern char __bss_end;
  extern char __heap_start;
  extern void* __brkval;

  int freeMemory() {
    int free_memory;
    if ((int)__brkval == 0)
      free_memory = ((int)&free_memory) - ((int)&__bss_end);
    else
      free_memory = ((int)&free_memory) - ((int)__brkval);
    return free_memory;
  }
}

#endif // !SDSUPPORT

#endif // __AVR__
