2 ; * FreeRTOS Kernel V10.4.6
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3 ; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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5 ; * SPDX-License-Identifier: MIT
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7 ; * Permission is hereby granted, free of charge, to any person obtaining a copy of
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8 ; * this software and associated documentation files (the "Software"), to deal in
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9 ; * the Software without restriction, including without limitation the rights to
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10 ; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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11 ; * the Software, and to permit persons to whom the Software is furnished to do so,
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12 ; * subject to the following conditions:
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14 ; * The above copyright notice and this permission notice shall be included in all
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15 ; * copies or substantial portions of the Software.
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17 ; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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18 ; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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19 ; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
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20 ; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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21 ; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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22 ; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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24 ; * https://www.FreeRTOS.org
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25 ; * https://github.com/FreeRTOS
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29 EXTERN vTaskSwitchContext
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30 EXTERN ulCriticalNesting
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32 EXTERN ulPortTaskHasFPUContext
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33 EXTERN ulAsmAPIPriorityMask
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35 portSAVE_CONTEXT macro
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37 ; Save the LR and SPSR onto the system mode stack before switching to
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38 ; system mode to save the remaining system mode registers
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39 SRSDB sp!, #SYS_MODE
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43 ; Push the critical nesting count
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44 LDR R2, =ulCriticalNesting
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48 ; Does the task have a floating point context that needs saving? If
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49 ; ulPortTaskHasFPUContext is 0 then no.
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50 LDR R2, =ulPortTaskHasFPUContext
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54 ; Save the floating point context, if any
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60 ; Save ulPortTaskHasFPUContext itself
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63 ; Save the stack pointer in the TCB
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64 LDR R0, =pxCurrentTCB
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70 ; /**********************************************************************/
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72 portRESTORE_CONTEXT macro
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74 ; Set the SP to point to the stack of the task being restored.
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75 LDR R0, =pxCurrentTCB
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79 ; Is there a floating point context to restore? If the restored
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80 ; ulPortTaskHasFPUContext is zero then no.
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81 LDR R0, =ulPortTaskHasFPUContext
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86 ; Restore the floating point context, if any
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92 ; Restore the critical section nesting depth
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93 LDR R0, =ulCriticalNesting
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97 ; Ensure the priority mask is correct for the critical nesting depth
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98 LDR R2, =portICCPMR_PRIORITY_MASK_REGISTER_ADDRESS
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101 LDRNE R4, =( configMAX_API_CALL_INTERRUPT_PRIORITY << portPRIORITY_SHIFT )
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104 ; Restore all system mode registers other than the SP (which is already
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108 ; Return to the task code, loading CPSR on the way.
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