/*
    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.
*/

        .global _vPortYield
		.extern _vTaskSwitchContext
		.extern uxCriticalNesting

_vPortYield:

		PUSH	SR						/* Save the SR used by the task.... */
		PUSH	W0						/* ....then disable interrupts. */
		MOV		#32, W0
		MOV		W0, SR
		PUSH	W1						/* Save registers to the stack. */
		PUSH.D	W2
		PUSH.D	W4
		PUSH.D	W6
		PUSH.D 	W8
		PUSH.D 	W10
		PUSH.D	W12
		PUSH	W14
		PUSH	RCOUNT
		PUSH	TBLPAG
		PUSH	ACCAL
		PUSH	ACCAH
		PUSH	ACCAU
		PUSH	ACCBL
		PUSH	ACCBH
		PUSH	ACCBU
		PUSH	DCOUNT
		PUSH	DOSTARTL
		PUSH	DOSTARTH
		PUSH	DOENDL
		PUSH	DOENDH
		
																						
		PUSH	CORCON
		PUSH	PSVPAG
		MOV		_uxCriticalNesting, W0		/* Save the critical nesting counter for the task. */
		PUSH	W0
		MOV		_pxCurrentTCB, W0			/* Save the new top of stack into the TCB. */
		MOV		W15, [W0]

		call 	_vTaskSwitchContext

		MOV		_pxCurrentTCB, W0			/* Restore the stack pointer for the task. */
		MOV		[W0], W15
		POP		W0							/* Restore the critical nesting counter for the task. */
		MOV		W0, _uxCriticalNesting
		POP		PSVPAG
		POP		CORCON
		POP		DOENDH
		POP		DOENDL
		POP		DOSTARTH
		POP		DOSTARTL
		POP		DCOUNT
		POP		ACCBU
		POP		ACCBH
		POP		ACCBL
		POP		ACCAU
		POP		ACCAH
		POP		ACCAL
		POP		TBLPAG
		POP		RCOUNT						/* Restore the registers from the stack. */
		POP		W14
		POP.D	W12
		POP.D	W10
		POP.D	W8
		POP.D	W6
		POP.D	W4
		POP.D	W2
		POP.D	W0
		POP		SR

        return

        .end
