2 FreeRTOS.org V4.7.2 - Copyright (C) 2003-2008 Richard Barry.
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4 This file is part of the FreeRTOS.org distribution.
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6 FreeRTOS.org is free software; you can redistribute it and/or modify
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7 it under the terms of the GNU General Public License as published by
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8 the Free Software Foundation; either version 2 of the License, or
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9 (at your option) any later version.
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11 FreeRTOS.org is distributed in the hope that it will be useful,
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12 but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 GNU General Public License for more details.
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16 You should have received a copy of the GNU General Public License
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17 along with FreeRTOS.org; if not, write to the Free Software
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18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 A special exception to the GPL can be applied should you wish to distribute
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21 a combined work that includes FreeRTOS.org, without being obliged to provide
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22 the source code for any proprietary components. See the licensing section
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23 of http://www.FreeRTOS.org for full details of how and when the exception
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26 ***************************************************************************
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28 Please ensure to read the configuration and relevant port sections of the
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29 online documentation.
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31 +++ http://www.FreeRTOS.org +++
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32 Documentation, latest information, license and contact details.
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34 +++ http://www.SafeRTOS.com +++
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35 A version that is certified for use in safety critical systems.
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37 +++ http://www.OpenRTOS.com +++
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38 Commercial support, development, porting, licensing and training services.
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40 ***************************************************************************
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43 /*-----------------------------------------------------------
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44 * Implementation of functions defined in portable.h for the ST STR75x ARM7
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46 *----------------------------------------------------------*/
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48 /* Library includes. */
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50 #include "75x_eic.h"
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52 /* Scheduler includes. */
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53 #include "FreeRTOS.h"
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56 /* Constants required to setup the initial stack. */
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57 #define portINITIAL_SPSR ( ( portSTACK_TYPE ) 0x1f ) /* System mode, ARM mode, interrupts enabled. */
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58 #define portTHUMB_MODE_BIT ( ( portSTACK_TYPE ) 0x20 )
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59 #define portINSTRUCTION_SIZE ( ( portSTACK_TYPE ) 4 )
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61 /* Constants required to handle critical sections. */
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62 #define portNO_CRITICAL_NESTING ( ( unsigned portLONG ) 0 )
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64 /* Prescale used on the timer clock when calculating the tick period. */
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65 #define portPRESCALE 20
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68 /*-----------------------------------------------------------*/
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70 /* Setup the TB to generate the tick interrupts. */
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71 static void prvSetupTimerInterrupt( void );
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73 /*-----------------------------------------------------------*/
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76 * Initialise the stack of a task to look exactly as if a call to
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77 * portSAVE_CONTEXT had been called.
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79 * See header file for description.
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81 portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
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83 portSTACK_TYPE *pxOriginalTOS;
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85 pxOriginalTOS = pxTopOfStack;
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87 /* Setup the initial stack of the task. The stack is set exactly as
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88 expected by the portRESTORE_CONTEXT() macro. */
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90 /* First on the stack is the return address - which in this case is the
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91 start of the task. The offset is added to make the return address appear
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92 as it would within an IRQ ISR. */
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93 *pxTopOfStack = ( portSTACK_TYPE ) pxCode + portINSTRUCTION_SIZE;
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96 *pxTopOfStack = ( portSTACK_TYPE ) 0xaaaaaaaa; /* R14 */
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98 *pxTopOfStack = ( portSTACK_TYPE ) pxOriginalTOS; /* Stack used when task starts goes in R13. */
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100 *pxTopOfStack = ( portSTACK_TYPE ) 0x12121212; /* R12 */
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102 *pxTopOfStack = ( portSTACK_TYPE ) 0x11111111; /* R11 */
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104 *pxTopOfStack = ( portSTACK_TYPE ) 0x10101010; /* R10 */
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106 *pxTopOfStack = ( portSTACK_TYPE ) 0x09090909; /* R9 */
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108 *pxTopOfStack = ( portSTACK_TYPE ) 0x08080808; /* R8 */
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110 *pxTopOfStack = ( portSTACK_TYPE ) 0x07070707; /* R7 */
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112 *pxTopOfStack = ( portSTACK_TYPE ) 0x06060606; /* R6 */
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114 *pxTopOfStack = ( portSTACK_TYPE ) 0x05050505; /* R5 */
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116 *pxTopOfStack = ( portSTACK_TYPE ) 0x04040404; /* R4 */
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118 *pxTopOfStack = ( portSTACK_TYPE ) 0x03030303; /* R3 */
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120 *pxTopOfStack = ( portSTACK_TYPE ) 0x02020202; /* R2 */
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122 *pxTopOfStack = ( portSTACK_TYPE ) 0x01010101; /* R1 */
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125 /* When the task starts is will expect to find the function parameter in
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127 *pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* R0 */
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130 /* The status register is set for system mode, with interrupts enabled. */
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131 *pxTopOfStack = ( portSTACK_TYPE ) portINITIAL_SPSR;
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133 #ifdef THUMB_INTERWORK
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135 /* We want the task to start in thumb mode. */
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136 *pxTopOfStack |= portTHUMB_MODE_BIT;
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142 /* Interrupt flags cannot always be stored on the stack and will
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143 instead be stored in a variable, which is then saved as part of the
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145 *pxTopOfStack = portNO_CRITICAL_NESTING;
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147 return pxTopOfStack;
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149 /*-----------------------------------------------------------*/
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151 portBASE_TYPE xPortStartScheduler( void )
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153 extern void vPortISRStartFirstTask( void );
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155 /* Start the timer that generates the tick ISR. Interrupts are disabled
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157 prvSetupTimerInterrupt();
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159 /* Start the first task. */
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160 vPortISRStartFirstTask();
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162 /* Should not get here! */
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165 /*-----------------------------------------------------------*/
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167 void vPortEndScheduler( void )
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169 /* It is unlikely that the ARM port will require this function as there
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170 is nothing to return to. */
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172 /*-----------------------------------------------------------*/
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174 static void prvSetupTimerInterrupt( void )
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176 EIC_IRQInitTypeDef EIC_IRQInitStructure;
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177 TB_InitTypeDef TB_InitStructure;
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179 /* Setup the EIC for the TB. */
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180 EIC_IRQInitStructure.EIC_IRQChannelCmd = ENABLE;
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181 EIC_IRQInitStructure.EIC_IRQChannel = TB_IRQChannel;
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182 EIC_IRQInitStructure.EIC_IRQChannelPriority = 1;
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183 EIC_IRQInit(&EIC_IRQInitStructure);
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185 /* Setup the TB for the generation of the tick interrupt. */
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186 TB_InitStructure.TB_Mode = TB_Mode_Timing;
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187 TB_InitStructure.TB_CounterMode = TB_CounterMode_Down;
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188 TB_InitStructure.TB_Prescaler = portPRESCALE;
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189 TB_InitStructure.TB_AutoReload = ( ( configCPU_CLOCK_HZ / ( portPRESCALE + 1 ) ) / configTICK_RATE_HZ ) + 1;
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190 TB_Init(&TB_InitStructure);
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192 /* Enable TB Update interrupt */
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193 TB_ITConfig(TB_IT_Update, ENABLE);
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195 /* Clear TB Update interrupt pending bit */
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196 TB_ClearITPendingBit(TB_IT_Update);
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201 /*-----------------------------------------------------------*/
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