2 FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.
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4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
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5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS tutorial books are available in pdf and paperback. *
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10 * Complete, revised, and edited pdf reference manuals are also *
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13 * Purchasing FreeRTOS documentation will not only help you, by *
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14 * ensuring you get running as quickly as possible and with an *
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15 * in-depth knowledge of how to use FreeRTOS, it will also help *
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16 * the FreeRTOS project to continue with its mission of providing *
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17 * professional grade, cross platform, de facto standard solutions *
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18 * for microcontrollers - completely free of charge! *
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20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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22 * Thank you for using FreeRTOS, and thank you for your support! *
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24 ***************************************************************************
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27 This file is part of the FreeRTOS distribution.
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29 FreeRTOS is free software; you can redistribute it and/or modify it under
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30 the terms of the GNU General Public License (version 2) as published by the
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31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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33 >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
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34 distribute a combined work that includes FreeRTOS without being obliged to
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35 provide the source code for proprietary components outside of the FreeRTOS
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38 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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39 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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40 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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41 details. You should have received a copy of the GNU General Public License
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42 and the FreeRTOS license exception along with FreeRTOS; if not it can be
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43 viewed here: http://www.freertos.org/a00114.html and also obtained by
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44 writing to Real Time Engineers Ltd., contact details for whom are available
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45 on the FreeRTOS WEB site.
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49 ***************************************************************************
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51 * Having a problem? Start by reading the FAQ "My application does *
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52 * not run, what could be wrong?" *
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54 * http://www.FreeRTOS.org/FAQHelp.html *
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56 ***************************************************************************
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59 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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60 license and Real Time Engineers Ltd. contact details.
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62 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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63 including FreeRTOS+Trace - an indispensable productivity tool, and our new
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64 fully thread aware and reentrant UDP/IP stack.
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66 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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67 Integrity Systems, who sell the code with commercial support,
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68 indemnification and middleware, under the OpenRTOS brand.
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70 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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71 engineered and independently SIL3 certified version for use in safety and
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72 mission critical applications that require provable dependability.
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75 /*-----------------------------------------------------------
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76 * Implementation of functions defined in portable.h for the ST STR75x ARM7
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78 *----------------------------------------------------------*/
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80 /* Library includes. */
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82 #include "75x_eic.h"
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84 /* Scheduler includes. */
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85 #include "FreeRTOS.h"
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88 /* Constants required to setup the initial stack. */
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89 #define portINITIAL_SPSR ( ( portSTACK_TYPE ) 0x1f ) /* System mode, ARM mode, interrupts enabled. */
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90 #define portTHUMB_MODE_BIT ( ( portSTACK_TYPE ) 0x20 )
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91 #define portINSTRUCTION_SIZE ( ( portSTACK_TYPE ) 4 )
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93 /* Constants required to handle critical sections. */
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94 #define portNO_CRITICAL_NESTING ( ( unsigned long ) 0 )
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96 /* Prescale used on the timer clock when calculating the tick period. */
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97 #define portPRESCALE 20
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100 /*-----------------------------------------------------------*/
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102 /* Setup the TB to generate the tick interrupts. */
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103 static void prvSetupTimerInterrupt( void );
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105 /*-----------------------------------------------------------*/
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108 * Initialise the stack of a task to look exactly as if a call to
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109 * portSAVE_CONTEXT had been called.
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111 * See header file for description.
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113 portSTACK_TYPE *pxPortInitialiseStack( portSTACK_TYPE *pxTopOfStack, pdTASK_CODE pxCode, void *pvParameters )
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115 portSTACK_TYPE *pxOriginalTOS;
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117 pxOriginalTOS = pxTopOfStack;
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119 /* To ensure asserts in tasks.c don't fail, although in this case the assert
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120 is not really required. */
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123 /* Setup the initial stack of the task. The stack is set exactly as
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124 expected by the portRESTORE_CONTEXT() macro. */
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126 /* First on the stack is the return address - which in this case is the
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127 start of the task. The offset is added to make the return address appear
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128 as it would within an IRQ ISR. */
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129 *pxTopOfStack = ( portSTACK_TYPE ) pxCode + portINSTRUCTION_SIZE;
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132 *pxTopOfStack = ( portSTACK_TYPE ) 0xaaaaaaaa; /* R14 */
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134 *pxTopOfStack = ( portSTACK_TYPE ) pxOriginalTOS; /* Stack used when task starts goes in R13. */
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136 *pxTopOfStack = ( portSTACK_TYPE ) 0x12121212; /* R12 */
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138 *pxTopOfStack = ( portSTACK_TYPE ) 0x11111111; /* R11 */
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140 *pxTopOfStack = ( portSTACK_TYPE ) 0x10101010; /* R10 */
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142 *pxTopOfStack = ( portSTACK_TYPE ) 0x09090909; /* R9 */
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144 *pxTopOfStack = ( portSTACK_TYPE ) 0x08080808; /* R8 */
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146 *pxTopOfStack = ( portSTACK_TYPE ) 0x07070707; /* R7 */
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148 *pxTopOfStack = ( portSTACK_TYPE ) 0x06060606; /* R6 */
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150 *pxTopOfStack = ( portSTACK_TYPE ) 0x05050505; /* R5 */
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152 *pxTopOfStack = ( portSTACK_TYPE ) 0x04040404; /* R4 */
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154 *pxTopOfStack = ( portSTACK_TYPE ) 0x03030303; /* R3 */
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156 *pxTopOfStack = ( portSTACK_TYPE ) 0x02020202; /* R2 */
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158 *pxTopOfStack = ( portSTACK_TYPE ) 0x01010101; /* R1 */
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161 /* When the task starts is will expect to find the function parameter in
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163 *pxTopOfStack = ( portSTACK_TYPE ) pvParameters; /* R0 */
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166 /* The status register is set for system mode, with interrupts enabled. */
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167 *pxTopOfStack = ( portSTACK_TYPE ) portINITIAL_SPSR;
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169 #ifdef THUMB_INTERWORK
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171 /* We want the task to start in thumb mode. */
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172 *pxTopOfStack |= portTHUMB_MODE_BIT;
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178 /* Interrupt flags cannot always be stored on the stack and will
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179 instead be stored in a variable, which is then saved as part of the
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181 *pxTopOfStack = portNO_CRITICAL_NESTING;
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183 return pxTopOfStack;
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185 /*-----------------------------------------------------------*/
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187 portBASE_TYPE xPortStartScheduler( void )
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189 extern void vPortISRStartFirstTask( void );
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191 /* Start the timer that generates the tick ISR. Interrupts are disabled
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193 prvSetupTimerInterrupt();
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195 /* Start the first task. */
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196 vPortISRStartFirstTask();
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198 /* Should not get here! */
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201 /*-----------------------------------------------------------*/
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203 void vPortEndScheduler( void )
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205 /* It is unlikely that the ARM port will require this function as there
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206 is nothing to return to. */
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208 /*-----------------------------------------------------------*/
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210 static void prvSetupTimerInterrupt( void )
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212 EIC_IRQInitTypeDef EIC_IRQInitStructure;
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213 TB_InitTypeDef TB_InitStructure;
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215 /* Setup the EIC for the TB. */
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216 EIC_IRQInitStructure.EIC_IRQChannelCmd = ENABLE;
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217 EIC_IRQInitStructure.EIC_IRQChannel = TB_IRQChannel;
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218 EIC_IRQInitStructure.EIC_IRQChannelPriority = 1;
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219 EIC_IRQInit(&EIC_IRQInitStructure);
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221 /* Setup the TB for the generation of the tick interrupt. */
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222 TB_InitStructure.TB_Mode = TB_Mode_Timing;
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223 TB_InitStructure.TB_CounterMode = TB_CounterMode_Down;
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224 TB_InitStructure.TB_Prescaler = portPRESCALE - 1;
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225 TB_InitStructure.TB_AutoReload = ( ( configCPU_CLOCK_HZ / portPRESCALE ) / configTICK_RATE_HZ );
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226 TB_Init(&TB_InitStructure);
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228 /* Enable TB Update interrupt */
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229 TB_ITConfig(TB_IT_Update, ENABLE);
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231 /* Clear TB Update interrupt pending bit */
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232 TB_ClearITPendingBit(TB_IT_Update);
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237 /*-----------------------------------------------------------*/
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