Source/portable/CodeWarrior/ColdFire_V2/port.c

/*
    FreeRTOS V7.0.0 - Copyright (C) 2011 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!

    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.
*/

/* 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;


#define portSAVE_CONTEXT()				\
	lea.l		(-60, %sp), %sp;		\
	movem.l		%d0-%fp, (%sp);			\
	move.l		pxCurrentTCB, %a0;		\
	move.l		%sp, (%a0);

#define portRESTORE_CONTEXT()			\
	move.l		pxCurrentTCB, %a0;		\
	move.l		(%a0), %sp;				\
	movem.l		(%sp), %d0-%fp;			\
	lea.l		%sp@(60), %sp;			\
	rte



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

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_INTFRCH == 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 );
}
/*-----------------------------------------------------------*/