text: /*
   * FreeRTOS Kernel V10.1.1
   * Copyright (C) 2018 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
   *
   * 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.
   *
   * http://www.FreeRTOS.org
   * http://aws.amazon.com/freertos
   *
   * 1 tab == 4 spaces!
   */
  
  /* FreeRTOS includes. */
  #include "FreeRTOS.h"
  #include "task.h"
  
  /* Library includes. */
  #include "board.h"
  
  /*
   * The FreeRTOS tick handler.  This function must be installed as the handler
   * for the timer used to generate the tick interrupt.  Note that the interrupt
   * generated by the PIT is shared by other system peripherals, so if the PIT is
   * used for Tick generation then FreeRTOS_Tick_Handler() can only be installed
   * directly as the PIT handler if no other system interrupts need to be
   * serviced.  If system interrupts other than the PIT need to be serviced then
   * install System_Handler() as the PIT interrupt handler in place of
   * FreeRTOS_Tick_Handler() and add additional interrupt processing into the
   * implementation of System_Handler().
   */
  extern void FreeRTOS_Tick_Handler( void );
  static void System_Handler( void );
  
  /*-----------------------------------------------------------*/
  
  static void System_Handler( void )
  {
  	/* See the comments above the function prototype in this file. */
  	FreeRTOS_Tick_Handler();
  }
  /*-----------------------------------------------------------*/
  
  /*
   * The application must provide a function that configures a peripheral to
   * create the FreeRTOS tick interrupt, then define configSETUP_TICK_INTERRUPT()
   * in FreeRTOSConfig.h to call the function.  This file contains a function
   * that is suitable for use on the Atmel SAMA5.
   */
  void vConfigureTickInterrupt( void )
  {
  	/* NOTE:  The PIT interrupt is cleared by the configCLEAR_TICK_INTERRUPT()
  	macro in FreeRTOSConfig.h. */
  
  	/* Enable the PIT clock. */
  	PMC->PMC_PCER0 = 1 << ID_PIT;
  
  	/* Initialize the PIT to the desired frequency - specified in uS. */
  	PIT_Init( 1000000UL / configTICK_RATE_HZ, BOARD_MCK / 1000000 );
  
  	/* Configure interrupt on PIT.  Note this is on the system interrupt, which
  	is shared with other system peripherals, so System_Handler() must be
  	installed in place of FreeRTOS_Tick_Handler() if other system handlers are
  	required.  The tick must be given the lowest priority (0 in the SAMA5 AIC) */
  	IRQ_ConfigureIT( ID_PIT, AIC_SMR_SRCTYPE_EXT_POSITIVE_EDGE, FreeRTOS_Tick_Handler );
  	/* See commend directly above IRQ_ConfigureIT( ID_PIT, 0, System_Handler ); */
  	IRQ_EnableIT( ID_PIT );
  	PIT_EnableIT();
  
  	/* Enable the pit. */
  	PIT_Enable();
  
  	/* Prevent compiler warnings in the case where System_Handler() is not used
  	as the handler.  See the comments above the System_Handler() function
  	prototype at the top of this file. */
  	( void ) System_Handler;
  }
  /*-----------------------------------------------------------*/
  
  