2 FreeRTOS V7.5.0 - Copyright (C) 2013 Real Time Engineers Ltd.
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4 VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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6 ***************************************************************************
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8 * FreeRTOS provides completely free yet professionally developed, *
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9 * robust, strictly quality controlled, supported, and cross *
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10 * platform software that has become a de facto standard. *
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12 * Help yourself get started quickly and support the FreeRTOS *
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13 * project by purchasing a FreeRTOS tutorial book, reference *
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14 * manual, or both from: http://www.FreeRTOS.org/Documentation *
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18 ***************************************************************************
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20 This file is part of the FreeRTOS distribution.
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22 FreeRTOS is free software; you can redistribute it and/or modify it under
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23 the terms of the GNU General Public License (version 2) as published by the
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24 Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
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26 >>! NOTE: The modification to the GPL is included to allow you to distribute
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27 >>! a combined work that includes FreeRTOS without being obliged to provide
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28 >>! the source code for proprietary components outside of the FreeRTOS
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31 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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32 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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33 FOR A PARTICULAR PURPOSE. Full license text is available from the following
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34 link: http://www.freertos.org/a00114.html
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38 ***************************************************************************
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40 * Having a problem? Start by reading the FAQ "My application does *
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41 * not run, what could be wrong?" *
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43 * http://www.FreeRTOS.org/FAQHelp.html *
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45 ***************************************************************************
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47 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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48 license and Real Time Engineers Ltd. contact details.
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50 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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51 including FreeRTOS+Trace - an indispensable productivity tool, a DOS
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52 compatible FAT file system, and our tiny thread aware UDP/IP stack.
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54 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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55 Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
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56 licenses offer ticketed support, indemnification and middleware.
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58 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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59 engineered and independently SIL3 certified version for use in safety and
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60 mission critical applications that require provable dependability.
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64 #include "FreeRTOSConfig.h"
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65 #include "portasm.h"
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67 IMPORT xTaskIncrementTick
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68 IMPORT vTaskSwitchContext
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69 IMPORT vPortSetupTimerInterrupt
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73 EXPORT xPortStartScheduler
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78 * The RTOS tick ISR.
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80 * If the cooperative scheduler is in use this simply increments the tick
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83 * If the preemptive scheduler is in use a context switch can also occur.
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88 call #xTaskIncrementTick
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90 jeq SkipContextSwitch
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91 call #vTaskSwitchContext
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95 /*-----------------------------------------------------------*/
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99 * Manual context switch called by the portYIELD() macro.
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103 /* Mimic an interrupt by pushing the SR. */
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106 /* Now the SR is stacked we can disable interrupts. */
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109 /* Save the context of the current task. */
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112 /* Switch to the highest priority task that is ready to run. */
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113 call #vTaskSwitchContext
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115 /* Restore the context of the new task. */
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116 portRESTORE_CONTEXT
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117 /*-----------------------------------------------------------*/
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121 * Start off the scheduler by initialising the RTOS tick timer, then restoring
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122 * the context of the first task.
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124 xPortStartScheduler:
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126 /* Setup the hardware to generate the tick. Interrupts are disabled
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127 when this function is called. */
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128 call #vPortSetupTimerInterrupt
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130 /* Restore the context of the first task that is going to run. */
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131 portRESTORE_CONTEXT
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132 /*-----------------------------------------------------------*/
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135 /* Install vTickISR as the timer A0 interrupt. */
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137 ORG 0xFFE0 + TIMERA0_VECTOR
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139 _vTickISR_: DC16 vTickISR
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