portasm.s

FreeRTOS - V5.1.1 Last Update: Nov 20 2008 http://sourceforge.net/projects/freertos/

/*
	FreeRTOS.org V5.1.1 - 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.

    ***************************************************************************
    ***************************************************************************
    *                                                                         *
    * SAVE TIME AND MONEY!  We can port FreeRTOS.org to your own hardware,    *
    * and even write all or part of your application on your behalf.          *
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    * expedite your project.                                                  *
    *                                                                         *
    ***************************************************************************
    ***************************************************************************

	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,
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*/

/*
 * Purpose: Lowest level routines for all ColdFire processors.
 *
 * Notes:
 * 
 * ulPortSetIPL() and mcf5xxx_wr_cacr() copied with permission from FreeScale
 * supplied source files.
 */

    .global ulPortSetIPL
    .global mcf5xxx_wr_cacr
    .global __cs3_isr_interrupt_80
    .global vPortStartFirstTask

    .text

.macro portSAVE_CONTEXT

	lea.l		(-60, %sp), %sp
	movem.l		%d0-%fp, (%sp)
	move.l		pxCurrentTCB, %a0
	move.l		%sp, (%a0)

	.endm

.macro portRESTORE_CONTEXT

	move.l		pxCurrentTCB, %a0
	move.l		(%a0), %sp
	movem.l		(%sp), %d0-%fp
	lea.l		%sp@(60), %sp
	rte

	.endm

/********************************************************************/
/*
 * This routines changes the IPL to the value passed into the routine.
 * It also returns the old IPL value back.
 * Calling convention from C:
 *   old_ipl = asm_set_ipl(new_ipl);
 * For the Diab Data C compiler, it passes return value thru D0.
 * Note that only the least significant three bits of the passed
 * value are used.
 */

ulPortSetIPL:
    link    A6,#-8
    movem.l D6-D7,(SP)

    move.w  SR,D7       /* current sr    */

    move.l  D7,D0       /* prepare return value  */
    andi.l  #0x0700,D0  /* mask out IPL  */
    lsr.l   #8,D0       /* IPL   */

    move.l  8(A6),D6    /* get argument  */
    andi.l  #0x07,D6    /* least significant three bits  */
    lsl.l   #8,D6       /* move over to make mask    */

    andi.l  #0x0000F8FF,D7  /* zero out current IPL  */
    or.l    D6,D7           /* place new IPL in sr   */
    move.w  D7,SR

    movem.l (SP),D6-D7
    lea     8(SP),SP
    unlk    A6
    rts
/********************************************************************/

mcf5xxx_wr_cacr:
    move.l  4(sp),d0
    .long   0x4e7b0002  /* movec d0,cacr   */
    nop
    rts

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

/* Yield interrupt. */
__cs3_isr_interrupt_80:
	portSAVE_CONTEXT
	jsr vPortYieldHandler
	portRESTORE_CONTEXT

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


vPortStartFirstTask:
	portRESTORE_CONTEXT

    .end