2 ; * FreeRTOS Kernel V11.2.0
3 ; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
5 ; * SPDX-License-Identifier: MIT
7 ; * Permission is hereby granted, free of charge, to any person obtaining a copy of
8 ; * this software and associated documentation files (the "Software"), to deal in
9 ; * the Software without restriction, including without limitation the rights to
10 ; * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
11 ; * the Software, and to permit persons to whom the Software is furnished to do so,
12 ; * subject to the following conditions:
14 ; * The above copyright notice and this permission notice shall be included in all
15 ; * copies or substantial portions of the Software.
17 ; * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 ; * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
19 ; * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
20 ; * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
21 ; * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 ; * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24 ; * https://www.FreeRTOS.org
25 ; * https://github.com/FreeRTOS
29 ; * The definition of the "register test" tasks, as described at the top of
34 .global xTaskIncrementTick
35 .global vTaskSwitchContext
36 .global vPortSetupTimerInterrupt
38 .global usCriticalNesting
40 .def vPortPreemptiveTickISR
41 .def vPortCooperativeTickISR
43 .def xPortStartScheduler
45 ;-----------------------------------------------------------
47 portSAVE_CONTEXT .macro
49 ;Save the remaining registers.
51 movx.w &usCriticalNesting, r14
53 mov_x &pxCurrentTCB, r12
56 ;-----------------------------------------------------------
58 portRESTORE_CONTEXT .macro
60 mov_x &pxCurrentTCB, r12
63 movx.w r15, &usCriticalNesting
70 ;-----------------------------------------------------------
75 ;* If the cooperative scheduler is in use this simply increments the tick
78 ;* If the preemptive scheduler is in use a context switch can also occur.
84 vPortPreemptiveTickISR: .asmfunc
86 ; The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs
87 ;to save it manually before it gets modified (interrupts get disabled).
91 call_x #xTaskIncrementTick
92 call_x #vTaskSwitchContext
96 ;-----------------------------------------------------------
100 vPortCooperativeTickISR: .asmfunc
102 ; The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs
103 ;to save it manually before it gets modified (interrupts get disabled).
107 call_x #xTaskIncrementTick
112 ;-----------------------------------------------------------
115 ; Manual context switch called by the portYIELD() macro.
122 ; The sr needs saving before it is modified.
125 ; Now the SR is stacked we can disable interrupts.
129 ; Save the context of the current task.
132 ; Select the next task to run.
133 call_x #vTaskSwitchContext
135 ; Restore the context of the new task.
138 ;-----------------------------------------------------------
142 ; Start off the scheduler by initialising the RTOS tick timer, then restoring
143 ; the context of the first task.
148 xPortStartScheduler: .asmfunc
150 ; Setup the hardware to generate the tick. Interrupts are disabled
151 ; when this function is called.
152 call_x #vPortSetupTimerInterrupt
154 ; Restore the context of the first task that is going to run.
157 ;-----------------------------------------------------------