2 ; FreeRTOS V7.1.1 - Copyright (C) 2012 Real Time Engineers Ltd.
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5 ; ***************************************************************************
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7 ; * FreeRTOS tutorial books are available in pdf and paperback. *
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8 ; * Complete, revised, and edited pdf reference manuals are also *
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11 ; * Purchasing FreeRTOS documentation will not only help you, by *
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12 ; * ensuring you get running as quickly as possible and with an *
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13 ; * in-depth knowledge of how to use FreeRTOS, it will also help *
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14 ; * the FreeRTOS project to continue with its mission of providing *
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15 ; * professional grade, cross platform, de facto standard solutions *
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16 ; * for microcontrollers - completely free of charge! *
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18 ; * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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20 ; * Thank you for using FreeRTOS, and thank you for your support! *
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22 ; ***************************************************************************
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25 ; This file is part of the FreeRTOS distribution.
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27 ; FreeRTOS is free software; you can redistribute it and/or modify it under
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28 ; the terms of the GNU General Public License (version 2) as published by the
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29 ; Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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30 ; >>>NOTE<<< The modification to the GPL is included to allow you to
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31 ; distribute a combined work that includes FreeRTOS without being obliged to
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32 ; provide the source code for proprietary components outside of the FreeRTOS
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33 ; kernel. FreeRTOS is distributed in the hope that it will be useful, but
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34 ; WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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35 ; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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36 ; more details. You should have received a copy of the GNU General Public
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37 ; License and the FreeRTOS license exception along with FreeRTOS; if not it
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38 ; can be viewed here: http://www.freertos.org/a00114.html and also obtained
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39 ; by writing to Richard Barry, contact details for whom are available on the
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40 ; FreeRTOS WEB site.
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42 ; 1 tab == 4 spaces!
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44 ; http://www.FreeRTOS.org - Documentation, latest information, license and
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47 ; http://www.SafeRTOS.com - A version that is certified for use in safety
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50 ; http://www.OpenRTOS.com - Commercial support, development, porting,
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51 ; licensing and training services.
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54 .extern pxCurrentTCB
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55 .extern vTaskSwitchContext
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56 .extern ulMaxSyscallInterruptPriorityConst
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58 .global PendSV_Handler
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60 .global vPortStartFirstTask
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61 .global vPortEnableVFP
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63 ;-----------------------------------------------------------
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68 PendSV_Handler: .type func
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71 ;Get the location of the current TCB.
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72 ldr.w r3, =pxCurrentTCB
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75 ;Is the task using the FPU context? If so, push high vfp registers.
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78 vstmdbeq r0!, {s16-s31}
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80 ;Save the core registers.
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81 stmdb r0!, {r4-r11, r14}
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83 ;Save the new top of stack into the first member of the TCB.
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86 stmdb sp!, {r3, r14}
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87 ldr.w r0, =ulMaxSyscallInterruptPriorityConst
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89 bl vTaskSwitchContext
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92 ldmia sp!, {r3, r14}
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94 ;The first item in pxCurrentTCB is the task top of stack.
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98 ;Pop the core registers.
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99 ldmia r0!, {r4-r11, r14}
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101 ;Is the task using the FPU context? If so, pop the high vfp registers too.
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104 vldmiaeq r0!, {s16-s31}
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109 .size PendSV_Handler, $-PendSV_Handler
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112 ;-----------------------------------------------------------
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117 SVC_Handler: .type func
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118 ;Get the location of the current TCB.
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119 ldr.w r3, =pxCurrentTCB
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122 ;Pop the core registers.
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123 ldmia r0!, {r4-r11, r14}
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128 .size SVC_Handler, $-SVC_Handler
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131 ;-----------------------------------------------------------
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136 vPortStartFirstTask .type func
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137 ;Use the NVIC offset register to locate the stack.
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138 ldr.w r0, =0xE000ED08
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141 ;Set the msp back to the start of the stack.
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143 ;Call SVC to start the first task.
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146 .size vPortStartFirstTask, $-vPortStartFirstTask
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149 ;-----------------------------------------------------------
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154 vPortEnableVFP .type func
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155 ;The FPU enable bits are in the CPACR.
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156 ldr.w r0, =0xE000ED88
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159 ;Enable CP10 and CP11 coprocessors, then save back.
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160 orr r1, r1, #( 0xf << 20 )
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163 .size vPortEnableVFP, $-vPortEnableVFP
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