| ;/*
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| ; * FreeRTOS Kernel <DEVELOPMENT BRANCH>
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| ; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
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| ; *
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| ; * SPDX-License-Identifier: MIT |
| ; * |
| ; * Permission is hereby granted, free of charge, to any person obtaining a copy of
|
| ; * this software and associated documentation files (the "Software"), to deal in
|
| ; * the Software without restriction, including without limitation the rights to
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| ; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
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| ; * the Software, and to permit persons to whom the Software is furnished to do so,
|
| ; * subject to the following conditions:
|
| ; *
|
| ; * The above copyright notice and this permission notice shall be included in all
|
| ; * copies or substantial portions of the Software.
|
| ; *
|
| ; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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| ; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
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| ; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
|
| ; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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| ; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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| ; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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| ; *
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| ; * https://www.FreeRTOS.org
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| ; * https://github.com/FreeRTOS
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| ; *
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| ; */
|
|
|
| RSEG ICODE:CODE
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| CODE32
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|
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| EXTERN vPortPreemptiveTick
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| EXTERN vTaskSwitchContext
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|
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| PUBLIC vPortYieldProcessor
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| PUBLIC vPortStartFirstTask
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| PUBLIC vPortPreemptiveTickISR
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|
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| #include "ISR_Support.h"
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|
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| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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| ; Starting the first task is just a matter of restoring the context that
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| ; was created by pxPortInitialiseStack().
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| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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| vPortStartFirstTask:
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| portRESTORE_CONTEXT
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|
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| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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| ; Manual context switch function. This is the SWI hander.
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| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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| vPortYieldProcessor:
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| ADD LR, LR, #4 ; Add 4 to the LR to make the LR appear exactly
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| ; as if the context was saved during and IRQ
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| ; handler.
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|
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| portSAVE_CONTEXT ; Save the context of the current task...
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| LDR R0, =vTaskSwitchContext ; before selecting the next task to execute.
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| mov lr, pc
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| BX R0
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| portRESTORE_CONTEXT ; Restore the context of the selected task.
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|
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| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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| ; Preemptive context switch function. This will only ever get used if
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| ; portUSE_PREEMPTION is set to 1 in portmacro.h.
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| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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| vPortPreemptiveTickISR:
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| portSAVE_CONTEXT ; Save the context of the current task.
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|
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| LDR R0, =vPortPreemptiveTick ; Increment the tick count - this may wake a task.
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| MOV lr, pc
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| BX R0
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|
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| portRESTORE_CONTEXT ; Restore the context of the selected task.
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|
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|
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| END
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|