/*    FreeRTOS V4.1.1 - Copyright (C) 2003-2006 Richard Barry.    MCF5235 Port - Copyright (C) 2006 Christian Walter.    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 as published by    the Free Software Foundation; either version 2 of the License, or    (at your option) any later version.    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    along with FreeRTOS; 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, 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.    ***************************************************************************    See http://www.FreeRTOS.org for documentation, latest information, license    and contact details.  Please ensure to read the configuration and relevant    port sections of the online documentation.    ****************************************************************************/#include <stdlib.h>#include "FreeRTOS.h"#include "FreeRTOSConfig.h"#include "task.h"/* ------------------------ Types ----------------------------------------- */typedef volatile unsigned long vuint32;typedef volatile unsigned short vuint16;typedef volatile unsigned char vuint8;/* ------------------------ Defines --------------------------------------- */#define portVECTOR_TABLE                __RAMVEC#define portVECTOR_SYSCALL              ( 32 + portTRAP_YIELD )#define portVECTOR_TIMER                ( 64 + 36 )#define MCF_PIT_PRESCALER               512UL#define MCF_PIT_TIMER_TICKS             ( FSYS_2 / MCF_PIT_PRESCALER )#define MCF_PIT_MODULUS_REGISTER(freq)  ( MCF_PIT_TIMER_TICKS / ( freq ) - 1UL)#define MCF_PIT_PMR0                    ( *( vuint16 * )( void * )( &__IPSBAR[ 0x150002 ] ) )#define MCF_PIT_PCSR0                   ( *( vuint16 * )( void * )( &__IPSBAR[ 0x150000 ] ) )#define MCF_PIT_PCSR_PRE(x)             ( ( ( x ) & 0x000F ) << 8 )#define MCF_PIT_PCSR_EN                 ( 0x0001 )#define MCF_PIT_PCSR_RLD                ( 0x0002 )#define MCF_PIT_PCSR_PIF                ( 0x0004 )#define MCF_PIT_PCSR_PIE                ( 0x0008 )#define MCF_PIT_PCSR_OVW                ( 0x0010 )#define MCF_INTC0_ICR36                 ( *( vuint8 * )( void * )( &__IPSBAR[ 0x000C64 ] ) )#define MCF_INTC0_IMRH                  ( *( vuint32 * )( void * )( &__IPSBAR[ 0x000C08 ] ) )#define MCF_INTC0_IMRH_INT_MASK36       ( 0x00000010 )#define MCF_INTC0_IMRH_MASKALL          ( 0x00000001 )#define MCF_INTC0_ICRn_IP(x)            ( ( ( x ) & 0x07 ) << 0 )#define MCF_INTC0_ICRn_IL(x)            ( ( ( x ) & 0x07 ) << 3 )#define portNO_CRITICAL_NESTING         ( ( unsigned portLONG ) 0 )#define portINITIAL_CRITICAL_NESTING    ( ( unsigned portLONG ) 10 )/* ------------------------ Static variables ------------------------------ */volatile unsigned portLONG              ulCriticalNesting = portINITIAL_CRITICAL_NESTING;/* ------------------------ Static functions ------------------------------ */#if configUSE_PREEMPTION == 0static void prvPortPreemptiveTick ( void ) __attribute__ ((interrupt_handler));#elsestatic void prvPortPreemptiveTick ( void );#endif/* ------------------------ Start implementation -------------------------- */portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE * pxTopOfStack, pdTASK_CODE pxCode,                       void *pvParameters ){    /* Place the parameter on the stack in the expected location. */    *pxTopOfStack = ( portSTACK_TYPE ) pvParameters;    pxTopOfStack--;    /* Place dummy return address on stack. Tasks should never terminate so     * we can set this to anything. */    *pxTopOfStack = ( portSTACK_TYPE ) 0;    pxTopOfStack--;    /* Create a Motorola Coldfire exception stack frame. First comes the return     * address. */    *pxTopOfStack = ( portSTACK_TYPE ) pxCode;    pxTopOfStack--;    /* Format, fault-status, vector number for exception stack frame. Task     * run in supervisor mode. */    *pxTopOfStack = 0x40002000UL | ( portVECTOR_SYSCALL + 32 ) << 18;    pxTopOfStack--;    /* Set the initial critical section nesting counter to zero. This value     * is used to restore the value of ulCriticalNesting. */    *pxTopOfStack = 0;    *pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xA6;    /* A6 / FP */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xA5;    /* A5 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xA4;    /* A4 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xA3;    /* A3 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xA2;    /* A2 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xA1;    /* A1 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xA0;    /* A0 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD7;    /* D7 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD6;    /* D6 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD5;    /* D5 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD4;    /* D4 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD3;    /* D3 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD2;    /* D2 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD1;    /* D1 */    pxTopOfStack--;    *pxTopOfStack = ( portSTACK_TYPE ) 0xD0;    /* D0 */    return pxTopOfStack;}/* * Called by portYIELD() or taskYIELD() to manually force a context switch. */static voidprvPortYield( void ){    asm volatile ( "move.w  #0x2700, %sr\n\t" );#if _GCC_USES_FP == 1    asm volatile ( "unlk %fp\n\t" );#endif     /* Perform the context switch.  First save the context of the current task. */    portSAVE_CONTEXT(  );    /* Find the highest priority task that is ready to run. */    vTaskSwitchContext(  );    /* Restore the context of the new task. */    portRESTORE_CONTEXT(  );}#if configUSE_PREEMPTION == 0/* * The ISR used for the scheduler tick depends on whether the cooperative or * the preemptive scheduler is being used. */static voidprvPortPreemptiveTick ( void ){    /* The cooperative scheduler requires a normal IRQ service routine to     * simply increment the system tick.     */    vTaskIncrementTick(  );    MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIF;}#elsestatic voidprvPortPreemptiveTick( void ){    asm volatile ( "move.w  #0x2700, %sr\n\t" );#if _GCC_USES_FP == 1    asm volatile ( "unlk %fp\n\t" );#endif    portSAVE_CONTEXT(  );    MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIF;    vTaskIncrementTick(  );    vTaskSwitchContext(  );    portRESTORE_CONTEXT(  );}#endifvoidvPortEnterCritical(){    /* FIXME: We should store the old IPL here - How are we supposed to do     * this.     */    ( void )portSET_IPL( portIPL_MAX );    /* Now interrupts are disabled ulCriticalNesting can be accessed     * directly.  Increment ulCriticalNesting to keep a count of how many times     * portENTER_CRITICAL() has been called. */    ulCriticalNesting++;}voidvPortExitCritical(){    if( ulCriticalNesting > portNO_CRITICAL_NESTING )    {        /* Decrement the nesting count as we are leaving a critical section. */        ulCriticalNesting--;        /* If the nesting level has reached zero then interrupts should be        re-enabled. */        if( ulCriticalNesting == portNO_CRITICAL_NESTING )        {            ( void )portSET_IPL( 0 );        }    }}portBASE_TYPExPortStartScheduler( void ){    extern void     ( *portVECTOR_TABLE[  ] ) (  );    /* Add entry in vector table for yield system call. */    portVECTOR_TABLE[ portVECTOR_SYSCALL ] = prvPortYield;    /* Add entry in vector table for periodic timer. */    portVECTOR_TABLE[ portVECTOR_TIMER ] = prvPortPreemptiveTick;    /* Configure the timer for the system clock. */    if ( configTICK_RATE_HZ > 0)    {        /* Configure prescaler */        MCF_PIT_PCSR0 = MCF_PIT_PCSR_PRE( 0x9 ) | MCF_PIT_PCSR_RLD | MCF_PIT_PCSR_OVW;        /* Initialize the periodic timer interrupt. */        MCF_PIT_PMR0 = MCF_PIT_MODULUS_REGISTER( configTICK_RATE_HZ );        /* Configure interrupt priority and level and unmask interrupt. */        MCF_INTC0_ICR36 = MCF_INTC0_ICRn_IL( 0x1 ) | MCF_INTC0_ICRn_IP( 0x1 );        MCF_INTC0_IMRH &= ~( MCF_INTC0_IMRH_INT_MASK36 | MCF_INTC0_IMRH_MASKALL );        /* Enable interrupts */        MCF_PIT_PCSR0 |= MCF_PIT_PCSR_PIE | MCF_PIT_PCSR_EN | MCF_PIT_PCSR_PIF;    }    /* Restore the context of the first task that is going to run. */    portRESTORE_CONTEXT(  );    /* Should not get here. */    return pdTRUE;}voidvPortEndScheduler( void ){}