2 ; FreeRTOS V7.6.0 - Copyright (C) 2013 Real Time Engineers Ltd.
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3 ; All rights reserved
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6 ; ***************************************************************************
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8 ; * FreeRTOS tutorial books are available in pdf and paperback. *
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9 ; * Complete, revised, and edited pdf reference manuals are also *
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12 ; * Purchasing FreeRTOS documentation will not only help you, by *
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13 ; * ensuring you get running as quickly as possible and with an *
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14 ; * in-depth knowledge of how to use FreeRTOS, it will also help *
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15 ; * the FreeRTOS project to continue with its mission of providing *
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16 ; * professional grade, cross platform, de facto standard solutions *
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17 ; * for microcontrollers - completely free of charge! *
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19 ; * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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21 ; * Thank you for using FreeRTOS, and thank you for your support! *
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23 ; ***************************************************************************
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26 ; This file is part of the FreeRTOS distribution.
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28 ; FreeRTOS is free software; you can redistribute it and/or modify it under
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29 ; the terms of the GNU General Public License (version 2) as published by the
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30 ; Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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31 ; >>>NOTE<<< The modification to the GPL is included to allow you to
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32 ; distribute a combined work that includes FreeRTOS without being obliged to
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33 ; provide the source code for proprietary components outside of the FreeRTOS
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34 ; kernel. FreeRTOS is distributed in the hope that it will be useful, but
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35 ; WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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36 ; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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37 ; more details. You should have received a copy of the GNU General Public
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38 ; License and the FreeRTOS license exception along with FreeRTOS; if not it
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39 ; can be viewed here: http://www.freertos.org/a00114.html and also obtained
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40 ; by writing to Richard Barry, contact details for whom are available on the
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41 ; FreeRTOS WEB site.
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43 ; 1 tab == 4 spaces!
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45 ; http://www.FreeRTOS.org - Documentation, latest information, license and
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48 ; http://www.SafeRTOS.com - A version that is certified for use in safety
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51 ; http://www.OpenRTOS.com - Commercial support, development, porting,
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52 ; licensing and training services.
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56 EXTERN ulCriticalNesting
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58 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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59 ; Context save and restore macro definitions
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60 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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62 portSAVE_CONTEXT MACRO
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64 ; Push R0 as we are going to use the register.
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67 ; Set R0 to point to the task stack pointer.
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73 ; Push the return address onto the stack.
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76 ; Now we have saved LR we can use it instead of R0.
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79 ; Pop R0 so we can save it onto the system mode stack.
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82 ; Push all the system mode registers onto the task stack.
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87 ; Push the SPSR onto the task stack.
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91 LDR R0, =ulCriticalNesting
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95 ; Store the new top of stack for the task.
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96 LDR R1, =pxCurrentTCB
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103 portRESTORE_CONTEXT MACRO
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105 ; Set the LR to the task stack.
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106 LDR R1, =pxCurrentTCB
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110 ; The critical nesting depth is the first item on the stack.
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111 ; Load it into the ulCriticalNesting variable.
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112 LDR R0, =ulCriticalNesting
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116 ; Get the SPSR from the stack.
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120 ; Restore all system mode registers for the task.
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121 LDMFD LR, {R0-R14}^
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124 ; Restore the return address.
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127 ; And return - correcting the offset in the LR to obtain the
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128 ; correct address.
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