/*
    FreeRTOS V6.0.1 - Copyright (C) 2009 Real Time Engineers Ltd.

    ***************************************************************************
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    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
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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 _ulPortSetIPL
    .global mcf5xxx_wr_cacrx
    .global _mcf5xxx_wr_cacrx
    .global vPortYieldISR
    .global _vPortYieldISR
    .global vPortStartFirstTask
    .global _vPortStartFirstTask
    .extern _pxCurrentTCB
    .extern _vPortYieldHandler

    .text

.macro portSAVE_CONTEXT

	lea.l		(-60, sp), sp
	movem.l		d0-a6, (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-a6
	lea.l		(60, sp), 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:
_ulPortSetIPL:
    link    A6,#-8
    movem.l D6-D7,(SP)

    move.w  SR,D7       /* current sr    */

    move.l  D7,D6       /* prepare return value  */
    andi.l  #0x0700,D6  /* mask out IPL  */
    lsr.l   #8,D6       /* IPL   */

    andi.l  #0x07,D0    /* least significant three bits  */
    lsl.l   #8,D0       /* move over to make mask    */

    andi.l  #0x0000F8FF,D7  /* zero out current IPL  */
    or.l    D0,D7           /* place new IPL in sr   */
    move.w  D7,SR

	move.l	D6, D0		/* Return value in D0. */
    movem.l (SP),D6-D7
    lea     8(SP),SP
    unlk    A6
    rts
/********************************************************************/

mcf5xxx_wr_cacrx:
_mcf5xxx_wr_cacrx:
    move.l  4(sp),d0
    .long   0x4e7b0002  /* movec d0,cacr   */
    nop
    rts

/********************************************************************/

/* Yield interrupt. */
_vPortYieldISR:
vPortYieldISR:
	portSAVE_CONTEXT
	jsr _vPortYieldHandler
	portRESTORE_CONTEXT

/********************************************************************/


vPortStartFirstTask:
_vPortStartFirstTask:
	portRESTORE_CONTEXT

    .end