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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Source/] [portable/] [GCC/] [MCF5235/] [port.c] - Blame information for rev 820

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1 572 jeremybenn
/*
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    FreeRTOS V4.1.1 - Copyright (C) 2003-2006 Richard Barry.
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    MCF5235 Port - Copyright (C) 2006 Christian Walter.
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    This file is part of the FreeRTOS distribution.
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    FreeRTOS is free software; you can redistribute it and/or modify
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    it under the terms of the GNU General Public License** as published by
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    the Free Software Foundation; either version 2 of the License, or
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    (at your option) any later version.
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    FreeRTOS is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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    GNU General Public License for more details.
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    You should have received a copy of the GNU General Public License
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    along with FreeRTOS; if not, write to the Free Software
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    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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    A special exception to the GPL can be applied should you wish to distribute
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    a combined work that includes FreeRTOS, without being obliged to provide
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    the source code for any proprietary components.  See the licensing section
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    of http://www.FreeRTOS.org for full details of how and when the exception
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    can be applied.
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    ***************************************************************************
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    ***************************************************************************
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    *                                                                         *
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    * Get the FreeRTOS eBook!  See http://www.FreeRTOS.org/Documentation      *
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        *                                                                         *
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        * This is a concise, step by step, 'hands on' guide that describes both   *
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        * general multitasking concepts and FreeRTOS specifics. It presents and   *
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        * explains numerous examples that are written using the FreeRTOS API.     *
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        * Full source code for all the examples is provided in an accompanying    *
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        * .zip file.                                                              *
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    *                                                                         *
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    ***************************************************************************
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    ***************************************************************************
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        Please ensure to read the configuration and relevant port sections of the
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        online documentation.
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        http://www.FreeRTOS.org - Documentation, latest information, license and
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        contact details.
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        http://www.SafeRTOS.com - A version that is certified for use in safety
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        critical systems.
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        http://www.OpenRTOS.com - Commercial support, development, porting,
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        licensing and training services.
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*/
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#include <stdlib.h>
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#include "FreeRTOS.h"
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#include "FreeRTOSConfig.h"
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#include "task.h"
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/* ------------------------ Types ----------------------------------------- */
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typedef volatile unsigned long vuint32;
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typedef volatile unsigned short vuint16;
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typedef volatile unsigned char vuint8;
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/* ------------------------ Defines --------------------------------------- */
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#define portVECTOR_TABLE                __RAMVEC
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#define portVECTOR_SYSCALL              ( 32 + portTRAP_YIELD )
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#define portVECTOR_TIMER                ( 64 + 36 )
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#define MCF_PIT_PRESCALER               512UL
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#define MCF_PIT_TIMER_TICKS             ( FSYS_2 / MCF_PIT_PRESCALER )
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#define MCF_PIT_MODULUS_REGISTER(freq)  ( MCF_PIT_TIMER_TICKS / ( freq ) - 1UL)
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#define MCF_PIT_PMR0                    ( *( vuint16 * )( void * )( &__IPSBAR[ 0x150002 ] ) )
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#define MCF_PIT_PCSR0                   ( *( vuint16 * )( void * )( &__IPSBAR[ 0x150000 ] ) )
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#define MCF_PIT_PCSR_PRE(x)             ( ( ( x ) & 0x000F ) << 8 )
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#define MCF_PIT_PCSR_EN                 ( 0x0001 )
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#define MCF_PIT_PCSR_RLD                ( 0x0002 )
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#define MCF_PIT_PCSR_PIF                ( 0x0004 )
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#define MCF_PIT_PCSR_PIE                ( 0x0008 )
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#define MCF_PIT_PCSR_OVW                ( 0x0010 )
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#define MCF_INTC0_ICR36                 ( *( vuint8 * )( void * )( &__IPSBAR[ 0x000C64 ] ) )
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#define MCF_INTC0_IMRH                  ( *( vuint32 * )( void * )( &__IPSBAR[ 0x000C08 ] ) )
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#define MCF_INTC0_IMRH_INT_MASK36       ( 0x00000010 )
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#define MCF_INTC0_IMRH_MASKALL          ( 0x00000001 )
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#define MCF_INTC0_ICRn_IP(x)            ( ( ( x ) & 0x07 ) << 0 )
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#define MCF_INTC0_ICRn_IL(x)            ( ( ( x ) & 0x07 ) << 3 )
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#define portNO_CRITICAL_NESTING         ( ( unsigned long ) 0 )
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#define portINITIAL_CRITICAL_NESTING    ( ( unsigned long ) 10 )
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/* ------------------------ Static variables ------------------------------ */
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volatile unsigned long              ulCriticalNesting = portINITIAL_CRITICAL_NESTING;
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/* ------------------------ Static functions ------------------------------ */
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#if configUSE_PREEMPTION == 0
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static void prvPortPreemptiveTick ( void ) __attribute__ ((interrupt_handler));
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#else
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static void prvPortPreemptiveTick ( void );
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#endif
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/* ------------------------ Start implementation -------------------------- */
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portSTACK_TYPE *
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pxPortInitialiseStack( portSTACK_TYPE * pxTopOfStack, pdTASK_CODE pxCode,
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                       void *pvParameters )
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{
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    /* Place the parameter on the stack in the expected location. */
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    *pxTopOfStack = ( portSTACK_TYPE ) pvParameters;
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    pxTopOfStack--;
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    /* Place dummy return address on stack. Tasks should never terminate so
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     * we can set this to anything. */
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    *pxTopOfStack = ( portSTACK_TYPE ) 0;
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    pxTopOfStack--;
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    /* Create a Motorola Coldfire exception stack frame. First comes the return
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     * address. */
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    *pxTopOfStack = ( portSTACK_TYPE ) pxCode;
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    pxTopOfStack--;
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    /* Format, fault-status, vector number for exception stack frame. Task
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     * run in supervisor mode. */
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    *pxTopOfStack = 0x40002000UL | ( portVECTOR_SYSCALL + 32 ) << 18;
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    pxTopOfStack--;
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    /* Set the initial critical section nesting counter to zero. This value
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     * is used to restore the value of ulCriticalNesting. */
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    *pxTopOfStack = 0;
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    *pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xA6;    /* A6 / FP */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xA5;    /* A5 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xA4;    /* A4 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xA3;    /* A3 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xA2;    /* A2 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xA1;    /* A1 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xA0;    /* A0 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD7;    /* D7 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD6;    /* D6 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD5;    /* D5 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD4;    /* D4 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD3;    /* D3 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD2;    /* D2 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD1;    /* D1 */
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    pxTopOfStack--;
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    *pxTopOfStack = ( portSTACK_TYPE ) 0xD0;    /* D0 */
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    return pxTopOfStack;
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}
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/*
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 * Called by portYIELD() or taskYIELD() to manually force a context switch.
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 */
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static void
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prvPortYield( void )
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{
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    asm volatile ( "move.w  #0x2700, %sr\n\t" );
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#if _GCC_USES_FP == 1
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    asm volatile ( "unlk %fp\n\t" );
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#endif
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     /* Perform the context switch.  First save the context of the current task. */
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    portSAVE_CONTEXT(  );
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    /* Find the highest priority task that is ready to run. */
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    vTaskSwitchContext(  );
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    /* Restore the context of the new task. */
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    portRESTORE_CONTEXT(  );
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}
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#if configUSE_PREEMPTION == 0
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/*
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 * The ISR used for the scheduler tick depends on whether the cooperative or
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 * the preemptive scheduler is being used.
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 */
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static void
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prvPortPreemptiveTick ( void )
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{
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    /* The cooperative scheduler requires a normal IRQ service routine to
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     * simply increment the system tick.
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     */
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    vTaskIncrementTick(  );
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    MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIF;
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}
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#else
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static void
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prvPortPreemptiveTick( void )
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{
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    asm volatile ( "move.w  #0x2700, %sr\n\t" );
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#if _GCC_USES_FP == 1
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    asm volatile ( "unlk %fp\n\t" );
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#endif
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    portSAVE_CONTEXT(  );
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    MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIF;
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    vTaskIncrementTick(  );
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    vTaskSwitchContext(  );
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    portRESTORE_CONTEXT(  );
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}
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#endif
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void
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vPortEnterCritical()
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{
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    /* FIXME: We should store the old IPL here - How are we supposed to do
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     * this.
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     */
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    ( void )portSET_IPL( portIPL_MAX );
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    /* Now interrupts are disabled ulCriticalNesting can be accessed
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     * directly.  Increment ulCriticalNesting to keep a count of how many times
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     * portENTER_CRITICAL() has been called. */
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    ulCriticalNesting++;
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}
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void
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vPortExitCritical()
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{
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    if( ulCriticalNesting > portNO_CRITICAL_NESTING )
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    {
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        /* Decrement the nesting count as we are leaving a critical section. */
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        ulCriticalNesting--;
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        /* If the nesting level has reached zero then interrupts should be
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        re-enabled. */
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        if( ulCriticalNesting == portNO_CRITICAL_NESTING )
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        {
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            ( void )portSET_IPL( 0 );
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        }
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    }
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}
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portBASE_TYPE
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xPortStartScheduler( void )
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{
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    extern void     ( *portVECTOR_TABLE[  ] ) (  );
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    /* Add entry in vector table for yield system call. */
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    portVECTOR_TABLE[ portVECTOR_SYSCALL ] = prvPortYield;
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    /* Add entry in vector table for periodic timer. */
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    portVECTOR_TABLE[ portVECTOR_TIMER ] = prvPortPreemptiveTick;
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    /* Configure the timer for the system clock. */
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    if ( configTICK_RATE_HZ > 0)
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    {
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        /* Configure prescaler */
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        MCF_PIT_PCSR0 = MCF_PIT_PCSR_PRE( 0x9 ) | MCF_PIT_PCSR_RLD | MCF_PIT_PCSR_OVW;
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        /* Initialize the periodic timer interrupt. */
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        MCF_PIT_PMR0 = MCF_PIT_MODULUS_REGISTER( configTICK_RATE_HZ );
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        /* Configure interrupt priority and level and unmask interrupt. */
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        MCF_INTC0_ICR36 = MCF_INTC0_ICRn_IL( 0x1 ) | MCF_INTC0_ICRn_IP( 0x1 );
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        MCF_INTC0_IMRH &= ~( MCF_INTC0_IMRH_INT_MASK36 | MCF_INTC0_IMRH_MASKALL );
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        /* Enable interrupts */
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        MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIE | MCF_PIT_PCSR_EN | MCF_PIT_PCSR_PIF;
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    }
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    /* Restore the context of the first task that is going to run. */
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    portRESTORE_CONTEXT(  );
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    /* Should not get here. */
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    return pdTRUE;
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}
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void
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vPortEndScheduler( void )
282
{
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}

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