Subversion Repositories openrisc_2011-10-31

/*
    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.

    ***************************************************************************
    *                                                                         *
    * If you are:                                                             *
    *                                                                         *
    *    + New to FreeRTOS,                                                   *
    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
    *    + Looking for basic training,                                        *
    *    + Wanting to improve your FreeRTOS skills and productivity           *
    *                                                                         *
    * then take a look at the FreeRTOS books - available as PDF or paperback  *
    *                                                                         *
    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
    *                  http://www.FreeRTOS.org/Documentation                  *
    *                                                                         *
    * A pdf reference manual is also available.  Both are usually delivered   *
    * to your inbox within 20 minutes to two hours when purchased between 8am *
    * and 8pm GMT (although please allow up to 24 hours in case of            *
    * exceptional circumstances).  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 exception 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.
*/

        .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