text: /*
      FreeRTOS V7.1.1 - Copyright (C) 2012 Real Time Engineers Ltd.
  	
  
      ***************************************************************************
       *                                                                       *
       *    FreeRTOS tutorial books are available in pdf and paperback.        *
       *    Complete, revised, and edited pdf reference manuals are also       *
       *    available.                                                         *
       *                                                                       *
       *    Purchasing FreeRTOS documentation will not only help you, by       *
       *    ensuring you get running as quickly as possible and with an        *
       *    in-depth knowledge of how to use FreeRTOS, it will also help       *
       *    the FreeRTOS project to continue with its mission of providing     *
       *    professional grade, cross platform, de facto standard solutions    *
       *    for microcontrollers - completely free of charge!                  *
       *                                                                       *
       *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
       *                                                                       *
       *    Thank you for using FreeRTOS, and thank you for your support!      *
       *                                                                       *
      ***************************************************************************
  
  
      This file is part of the FreeRTOS distribution.
  
      FreeRTOS is free software; you can redistribute it and/or modify it under
      the terms of the GNU General Public License (version 2) as published by the
      Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
      >>>NOTE<<< The modification to the GPL is included to allow you to
      distribute a combined work that includes FreeRTOS without being obliged to
      provide the source code for proprietary components outside of the FreeRTOS
      kernel.  FreeRTOS 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 and the FreeRTOS license exception along with FreeRTOS; if not it
      can be viewed here: http://www.freertos.org/a00114.html and also obtained
      by writing to Richard Barry, contact details for whom are available on the
      FreeRTOS WEB site.
  
      1 tab == 4 spaces!
      
      ***************************************************************************
       *                                                                       *
       *    Having a problem?  Start by reading the FAQ "My application does   *
       *    not run, what could be wrong?                                      *
       *                                                                       *
       *    http://www.FreeRTOS.org/FAQHelp.html                               *
       *                                                                       *
      ***************************************************************************
  
      
      http://www.FreeRTOS.org - Documentation, training, latest information, 
      license and contact details.
      
      http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
      including FreeRTOS+Trace - an indispensable productivity tool.
  
      Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell 
      the code with commercial support, indemnification, and middleware, under 
      the OpenRTOS brand: http://www.OpenRTOS.com.  High Integrity Systems also
      provide a safety engineered and independently SIL3 certified version under 
      the SafeRTOS brand: http://www.SafeRTOS.com.
  */
  
  /* Kernel includes. */
  #include "FreeRTOS.h"
  #include "task.h"
  
  #define portINITIAL_FORMAT_VECTOR		( ( portSTACK_TYPE ) 0x4000 )
  
  /* Supervisor mode set. */
  #define portINITIAL_STATUS_REGISTER		( ( portSTACK_TYPE ) 0x2000)
  
  /* Used to keep track of the number of nested calls to taskENTER_CRITICAL().  This
  will be set to 0 prior to the first task being started. */
  static unsigned long ulCriticalNesting = 0x9999UL;
  
  /*-----------------------------------------------------------*/
  
  portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE * pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
  {
  	*pxTopOfStack = ( portSTACK_TYPE ) pvParameters;
  	pxTopOfStack--;
  
  	*pxTopOfStack = (portSTACK_TYPE) 0xDEADBEEF;
  	pxTopOfStack--;
  
  	/* Exception stack frame starts with the return address. */
  	*pxTopOfStack = ( portSTACK_TYPE ) pxCode;
  	pxTopOfStack--;
  
  	*pxTopOfStack = ( portINITIAL_FORMAT_VECTOR << 16UL ) | ( portINITIAL_STATUS_REGISTER );
  	pxTopOfStack--;
  
  	*pxTopOfStack = ( portSTACK_TYPE ) 0x0; /*FP*/
  	pxTopOfStack -= 14; /* A5 to D0. */
  
      return pxTopOfStack;
  }
  /*-----------------------------------------------------------*/
  
  portBASE_TYPE xPortStartScheduler( void )
  {
  extern void vPortStartFirstTask( void );
  
  	ulCriticalNesting = 0UL;
  
  	/* Configure the interrupts used by this port. */
  	vApplicationSetupInterrupts();
  
  	/* Start the first task executing. */
  	vPortStartFirstTask();
  
  	return pdFALSE;
  }
  /*-----------------------------------------------------------*/
  
  void vPortEndScheduler( void )
  {
  	/* Not implemented as there is nothing to return to. */
  }
  /*-----------------------------------------------------------*/
  
  void vPortEnterCritical( void )
  {
  	if( ulCriticalNesting == 0UL )
  	{
  		/* Guard against context switches being pended simultaneously with a
  		critical section being entered. */
  		do
  		{
  			portDISABLE_INTERRUPTS();
  			if( MCF_INTC0_INTFRCL == 0UL )
  			{
  				break;
  			}
  
  			portENABLE_INTERRUPTS();
  
  		} while( 1 );
  	}
  	ulCriticalNesting++;
  }
  /*-----------------------------------------------------------*/
  
  void vPortExitCritical( void )
  {
  	ulCriticalNesting--;
  	if( ulCriticalNesting == 0 )
  	{
  		portENABLE_INTERRUPTS();
  	}
  }
  /*-----------------------------------------------------------*/
  
  void vPortYieldHandler( void )
  {
  unsigned long ulSavedInterruptMask;
  
  	ulSavedInterruptMask = portSET_INTERRUPT_MASK_FROM_ISR();
  		/* Note this will clear all forced interrupts - this is done for speed. */
  		MCF_INTC0_INTFRCL = 0;
  		vTaskSwitchContext();
  	portCLEAR_INTERRUPT_MASK_FROM_ISR( ulSavedInterruptMask );
  }
  
  
  
  
  
  
  