git.sur5r.net Git - freertos/blob - Source/portable/GCC/CORTUS_APS3/port.c

   1 /*
   2     FreeRTOS V6.0.4 - Copyright (C) 2010 Real Time Engineers Ltd.
   3
   4     ***************************************************************************
   5     *                                                                         *
   6     * If you are:                                                             *
   7     *                                                                         *
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  10     *    + Looking for basic training,                                        *
  11     *    + Wanting to improve your FreeRTOS skills and productivity           *
  12     *                                                                         *
  13     * then take a look at the FreeRTOS eBook                                  *
  14     *                                                                         *
  15     *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
  16     *                  http://www.FreeRTOS.org/Documentation                  *
  17     *                                                                         *
  18     * A pdf reference manual is also available.  Both are usually delivered   *
  19     * to your inbox within 20 minutes to two hours when purchased between 8am *
  20     * and 8pm GMT (although please allow up to 24 hours in case of            *
  21     * exceptional circumstances).  Thank you for your support!                *
  22     *                                                                         *
  23     ***************************************************************************
  24
  25     This file is part of the FreeRTOS distribution.
  26
  27     FreeRTOS is free software; you can redistribute it and/or modify it under
  28     the terms of the GNU General Public License (version 2) as published by the
  29     Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
  30     ***NOTE*** The exception to the GPL is included to allow you to distribute
  31     a combined work that includes FreeRTOS without being obliged to provide the
  32     source code for proprietary components outside of the FreeRTOS kernel.
  33     FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
  34     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  35     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  36     more details. You should have received a copy of the GNU General Public
  37     License and the FreeRTOS license exception along with FreeRTOS; if not it
  38     can be viewed here: http://www.freertos.org/a00114.html and also obtained
  39     by writing to Richard Barry, contact details for whom are available on the
  40     FreeRTOS WEB site.
  41
  42     1 tab == 4 spaces!
  43
  44     http://www.FreeRTOS.org - Documentation, latest information, license and
  45     contact details.
  46
  47     http://www.SafeRTOS.com - A version that is certified for use in safety
  48     critical systems.
  49
  50     http://www.OpenRTOS.com - Commercial support, development, porting,
  51     licensing and training services.
  52 */
  53
  54 /* Standard includes. */
  55 #include <stdlib.h>
  56
  57 /* Kernel includes. */
  58 #include "FreeRTOS.h"
  59 #include "task.h"
  60
  61 /* Machine includes */
  62 #include <machine/counter.h>
  63 #include <machine/ic.h>
  64 /*-----------------------------------------------------------*/
  65
  66 /* The initial PSR has the Previous Interrupt Enabled (PIEN) flag set. */
  67 #define portINITIAL_PSR                 ( 0x00020000 )
  68
  69 /*-----------------------------------------------------------*/
  70
  71 /*
  72  * Perform any hardware configuration necessary to generate the tick interrupt.
  73  */
  74 static void prvSetupTimerInterrupt( void );
  75 /*-----------------------------------------------------------*/
  76
  77 portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE * pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
  78 {
  79         /* Make space on the stack for the context - this leaves a couple of spaces
  80         empty.  */
  81         pxTopOfStack -= 20;
  82
  83         /* Fill the registers with known values to assist debugging. */
  84         pxTopOfStack[ 16 ] = portKERNEL_INTERRUPT_PRIORITY_LEVEL;
  85         pxTopOfStack[ 15 ] = portINITIAL_PSR;
  86         pxTopOfStack[ 14 ] = ( unsigned long ) pxCode;
  87         pxTopOfStack[ 13 ] = 0x00000000UL; /* R15. */
  88         pxTopOfStack[ 12 ] = 0x00000000UL; /* R14. */
  89         pxTopOfStack[ 11 ] = 0x0d0d0d0dUL;
  90         pxTopOfStack[ 10 ] = 0x0c0c0c0cUL;
  91         pxTopOfStack[ 9 ] = 0x0b0b0b0bUL;
  92         pxTopOfStack[ 8 ] = 0x0a0a0a0aUL;
  93         pxTopOfStack[ 7 ] = 0x09090909UL;
  94         pxTopOfStack[ 6 ] = 0x08080808UL;
  95         pxTopOfStack[ 5 ] = 0x07070707UL;
  96         pxTopOfStack[ 4 ] = 0x06060606UL;
  97         pxTopOfStack[ 3 ] = 0x05050505UL;
  98         pxTopOfStack[ 2 ] = 0x04040404UL;
  99         pxTopOfStack[ 1 ] = 0x03030303UL;
 100         pxTopOfStack[ 0 ] = ( unsigned long ) pvParameters;
 101
 102         return pxTopOfStack;
 103 }
 104 /*-----------------------------------------------------------*/
 105
 106 portBASE_TYPE xPortStartScheduler( void )
 107 {
 108         /* Set-up the timer interrupt. */
 109         prvSetupTimerInterrupt();
 110
 111         /* Enable the TRAP yield. */
 112         irq[ portIRQ_TRAP_YIELD ].ien = 1;
 113         irq[ portIRQ_TRAP_YIELD ].ipl = portKERNEL_INTERRUPT_PRIORITY_LEVEL;
 114
 115         /* Integrated Interrupt Controller: Enable all interrupts. */
 116         ic->ien = 1;
 117
 118         /* Restore callee saved registers. */
 119         portRESTORE_CONTEXT();
 120
 121         /* Should not get here. */
 122         return 0;
 123 }
 124 /*-----------------------------------------------------------*/
 125
 126 static void prvSetupTimerInterrupt( void )
 127 {
 128         /* Enable timer interrupts */
 129         counter1->reload = ( configCPU_CLOCK_HZ / configTICK_RATE_HZ ) - 1;
 130         counter1->value = counter1->reload;
 131         counter1->mask = 1;
 132
 133         /* Set the IRQ Handler priority and enable it. */
 134         irq[ IRQ_COUNTER1 ].ien = 1;
 135         irq[ IRQ_COUNTER1 ].ipl = portKERNEL_INTERRUPT_PRIORITY_LEVEL;
 136 }
 137 /*-----------------------------------------------------------*/
 138
 139 /* Trap 31 handler. */
 140 void interrupt31_handler( void ) __attribute__((naked));
 141 void interrupt31_handler( void )
 142 {
 143         portSAVE_CONTEXT();
 144         __asm volatile ( "call vTaskSwitchContext" );
 145         portRESTORE_CONTEXT();
 146 }
 147 /*-----------------------------------------------------------*/
 148
 149 static void prvProcessTick( void ) __attribute__((noinline));
 150 static void prvProcessTick( void )
 151 {
 152         vTaskIncrementTick();
 153
 154         #if configUSE_PREEMPTION == 1
 155                 vTaskSwitchContext();
 156         #endif
 157
 158         /* Clear the Tick Interrupt. */
 159         counter1->expired = 0;
 160 }
 161 /*-----------------------------------------------------------*/
 162
 163 /* Timer 1 interrupt handler, used for tick interrupt. */
 164 void interrupt7_handler( void ) __attribute__((naked));
 165 void interrupt7_handler( void )
 166 {
 167         portSAVE_CONTEXT();
 168         prvProcessTick();
 169         portRESTORE_CONTEXT();
 170 }
 171 /*-----------------------------------------------------------*/
 172
 173 void vPortEndScheduler( void )
 174 {
 175         /* Nothing to do. Unlikely to want to end. */
 176 }
 177 /*-----------------------------------------------------------*/