/*
	FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 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.

    ***************************************************************************
    ***************************************************************************
    *                                                                         *
    * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *
	*                                                                         *
	* This is a concise, step by step, 'hands on' guide that describes both   *
	* general multitasking concepts and FreeRTOS specifics. It presents and   *
	* explains numerous examples that are written using the FreeRTOS API.     *
	* Full source code for all the examples is provided in an accompanying    *
	* .zip file.                                                              *
    *                                                                         *
    ***************************************************************************
    ***************************************************************************

	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.
*/

        .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