/*
    FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.

    FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT 
    http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    ***************************************************************************
     *                                                                       *
     *    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 versions, 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)

/* The clock prescale into the timer peripheral. */
#define portPRESCALE_VALUE				( ( unsigned char ) 10 )

/* The clock frequency into the RTC. */
#define portRTC_CLOCK_HZ				( ( unsigned long ) 1000 )

asm void interrupt VectorNumber_VL1swi vPortYieldISR( void );
static void prvSetupTimerInterrupt( void );

/* 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 )
{

unsigned long ulOriginalA5;

	__asm{ MOVE.L A5, ulOriginalA5 };


	*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. */

	/* Parameter in A0. */
	*( pxTopOfStack + 8 ) = ( portSTACK_TYPE ) pvParameters;

	/* A5 must be maintained as it is resurved by the compiler. */
	*( pxTopOfStack + 13 ) = ulOriginalA5;

	return pxTopOfStack;  
}
/*-----------------------------------------------------------*/

portBASE_TYPE xPortStartScheduler( void )
{
extern void vPortStartFirstTask( void );

	ulCriticalNesting = 0UL;

	/* Configure a timer to generate the tick interrupt. */
	prvSetupTimerInterrupt();

	/* Start the first task executing. */
	vPortStartFirstTask();

	return pdFALSE;
}
/*-----------------------------------------------------------*/

static void prvSetupTimerInterrupt( void )
{				
	/* Prescale by 1 - ie no prescale. */
	RTCSC |= 8;
	
	/* Compare match value. */
	RTCMOD = portRTC_CLOCK_HZ / configTICK_RATE_HZ;
	
	/* Enable the RTC to generate interrupts - interrupts are already disabled
	when this code executes. */
	RTCSC_RTIE = 1;
}
/*-----------------------------------------------------------*/

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( INTC_FRC == 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. */
		INTC_CFRC = 0x3E;
		vTaskSwitchContext();
	}
	portCLEAR_INTERRUPT_MASK_FROM_ISR( ulSavedInterruptMask );
}
/*-----------------------------------------------------------*/

void interrupt VectorNumber_Vrtc vPortTickISR( void )
{
unsigned long ulSavedInterruptMask;

	/* Clear the interrupt. */
	RTCSC |= RTCSC_RTIF_MASK;

	/* Increment the RTOS tick. */
	ulSavedInterruptMask = portSET_INTERRUPT_MASK_FROM_ISR();
	{
		vTaskIncrementTick();
	}
	portCLEAR_INTERRUPT_MASK_FROM_ISR( ulSavedInterruptMask );

	/* If we are using the pre-emptive scheduler then also request a
	context switch as incrementing the tick could have unblocked a task. */
	#if configUSE_PREEMPTION == 1
	{
		taskYIELD();
	}
	#endif
}