/*
	FreeRTOS.org V4.7.1 - Copyright (C) 2003-2008 Richard Barry.

	This file is part of the FreeRTOS.org distribution.

	FreeRTOS.org 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 2 of the License, or
	(at your option) any later version.

	FreeRTOS.org 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 FreeRTOS.org; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

	A special exception to the GPL can be applied should you wish to distribute
	a combined work that includes FreeRTOS.org, without being obliged to provide
	the source code for any proprietary components.  See the licensing section 
	of http://www.FreeRTOS.org for full details of how and when the exception
	can be applied.

	***************************************************************************

	Please ensure to read the configuration and relevant port sections of the 
	online documentation.

	+++ http://www.FreeRTOS.org +++
	Documentation, latest information, license and contact details.  

	+++ http://www.SafeRTOS.com +++
	A version that is certified for use in safety critical systems.

	+++ http://www.OpenRTOS.com +++
	Commercial support, development, porting, licensing and training services.

	***************************************************************************
*/

/*-----------------------------------------------------------
 * Implementation of functions defined in portable.h for the MicroBlaze port.
 *----------------------------------------------------------*/


/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"

/* Library includes. */
#include "xexception_l.h"
#include "xtime_l.h"

/* Standard includes. */
#include <string.h>

/*-----------------------------------------------------------*/

#define portCRITICAL_INTERRUPT_ENABLE	( 1UL << 14UL )
#define portEXTERNAL_INTERRUPT_ENABLE	( 1UL << 16UL )
#define portMACHINE_CHECK_ENABLE		( 1UL << 19UL )
#define portINITIAL_MSR		( portCRITICAL_INTERRUPT_ENABLE | portEXTERNAL_INTERRUPT_ENABLE | portMACHINE_CHECK_ENABLE )

/*
 */
static void prvSetupTimerInterrupt( void );
extern void vStartFirstTask( void );
/*-----------------------------------------------------------*/

static void prvTickISR( void );
extern void vPortYield( void );

/* 
 * Initialise the stack of a task to look exactly as if a call to 
 * portSAVE_CONTEXT had been made.
 * 
 * See the header file portable.h.
 */
portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
{
	/* Place a known value at the bottom of the stack for debugging. */
	*pxTopOfStack = 0xDEADBEEF;
	*pxTopOfStack--;

	*pxTopOfStack = 0x10000001UL;;	/* R0. */
	pxTopOfStack--;
									/* SP. */
	*pxTopOfStack = 0x31313131UL;	/* R31. */
	pxTopOfStack--;
	*pxTopOfStack = 0x30303030UL;	/* R30. */
	pxTopOfStack--;
	*pxTopOfStack = 0x29292929UL;	/* R29. */
	pxTopOfStack--;
	*pxTopOfStack = 0x28282828UL;	/* R28. */
	pxTopOfStack--;
	*pxTopOfStack = 0x27272727UL;	/* R27. */
	pxTopOfStack--;
	*pxTopOfStack = 0x26262626UL;	/* R26. */
	pxTopOfStack--;
	*pxTopOfStack = 0x25252525UL;	/* R25. */
	pxTopOfStack--;
	*pxTopOfStack = 0x24242424UL;	/* R24. */
	pxTopOfStack--;
	*pxTopOfStack = 0x23232323UL;	/* R23. */
	pxTopOfStack--;
	*pxTopOfStack = 0x22222222UL;	/* R22. */
	pxTopOfStack--;
	*pxTopOfStack = 0x21212121UL;	/* R21. */
	pxTopOfStack--;
	*pxTopOfStack = 0x20202020UL;	/* R20. */
	pxTopOfStack--;
	*pxTopOfStack = 0x19191919UL;	/* R19. */
	pxTopOfStack--;
	*pxTopOfStack = 0x18181818UL;	/* R18. */
	pxTopOfStack--;
	*pxTopOfStack = 0x17171717UL;	/* R17. */
	pxTopOfStack--;
	*pxTopOfStack = 0x16161616UL;	/* R16. */
	pxTopOfStack--;
	*pxTopOfStack = 0x15151515UL;	/* R15. */
	pxTopOfStack--;
	*pxTopOfStack = 0x14141414UL;	/* R14. */
	pxTopOfStack--;
	*pxTopOfStack = 0x13131313UL;	/* R13. */
	pxTopOfStack--;
	*pxTopOfStack = 0x12121212UL;	/* R12. */
	pxTopOfStack--;
	*pxTopOfStack = 0x11111111UL;	/* R11. */
	pxTopOfStack--;
	*pxTopOfStack = 0x10101010UL;	/* R10. */
	pxTopOfStack--;
	*pxTopOfStack = 0x09090909UL;	/* R9. */
	pxTopOfStack--;
	*pxTopOfStack = 0x08080808UL;	/* R8. */
	pxTopOfStack--;
	*pxTopOfStack = 0x07070707UL;	/* R7. */
	pxTopOfStack--;
	*pxTopOfStack = 0x06060606UL;	/* R6. */
	pxTopOfStack--;
	*pxTopOfStack = 0x05050505UL;	/* R5. */
	pxTopOfStack--;
	*pxTopOfStack = 0x04040404UL;	/* R4. */
	pxTopOfStack--;
	*pxTopOfStack = ( portSTACK_TYPE ) pvParameters;
	pxTopOfStack--;
	*pxTopOfStack = 0x02020202UL;	/* R2. */
	pxTopOfStack--;
	*pxTopOfStack = 0x00000000;		/* CR. */
	pxTopOfStack--;
	*pxTopOfStack = 0x00000000;		/* XER. */
	pxTopOfStack--;
	*pxTopOfStack = 0x00000000;		/* LR. */
	pxTopOfStack--;
	*pxTopOfStack = 0x00000000;		/* CTR. */
	pxTopOfStack--;
	*pxTopOfStack = 0x00000000;		/* USPRG0. */
	pxTopOfStack--;
	*pxTopOfStack = ( portSTACK_TYPE ) pxCode; /* SRR0. */
	pxTopOfStack--;
	*pxTopOfStack = portINITIAL_MSR;/* SRR1. */
	pxTopOfStack--;

	return pxTopOfStack;
}
/*-----------------------------------------------------------*/

portBASE_TYPE xPortStartScheduler( void )
{
extern void *pxCurrentTCB;

	prvSetupTimerInterrupt();
	vStartFirstTask();
	
	/* Should not get here as the tasks are now running! */
	return pdFALSE;
}
/*-----------------------------------------------------------*/

void vPortEndScheduler( void )
{
	/* Not implemented. */
}
/*-----------------------------------------------------------*/

/*
 * Hardware initialisation to generate the RTOS tick.   
 */
static void prvSetupTimerInterrupt( void )
{
const unsigned portLONG ulInterval = ( ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1UL );

	XExc_Init();
	XExc_mDisableExceptions( XEXC_NON_CRITICAL ) ;	
	XExc_RegisterHandler( XEXC_ID_PIT_INT, ( XExceptionHandler ) prvTickISR, ( void * ) 0 );
	XExc_RegisterHandler( XEXC_ID_SYSTEM_CALL, ( XExceptionHandler ) vPortYield, ( void * ) 0 );

	XTime_PITEnableAutoReload();
	XTime_PITEnableInterrupt();
	XTime_PITSetInterval( ulInterval );
	XTime_PITEnableInterrupt();
	
	XExc_mEnableExceptions( XEXC_NON_CRITICAL ) ;
}
/*-----------------------------------------------------------*/

static void prvTickISR( void )
{
static unsigned portLONG ulTicks = 0;

	ulTicks++;
	if( ulTicks >= 1000 )
	{
		vParTestToggleLED( 0 );
		ulTicks = 0;
	}
	XTime_PITClearInterrupt();
	
	#if configUSE_PREEMPTION == 1
	#endif
}
/*-----------------------------------------------------------*/