xref: /Kernel-v10.6.2/portable/IAR/AtmelSAM9XE/portasm.s79 (revision ef7b253b56c9788077f5ecd6c9deb4021923d646) 
1;/*
2; * FreeRTOS Kernel V10.6.2
3; * Copyright (C) 2021 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
4; *
5; * SPDX-License-Identifier: MIT
6; *
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:
13; *
14; * The above copyright notice and this permission notice shall be included in all
15; * copies or substantial portions of the Software.
16; *
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.
23; *
24; * https://www.FreeRTOS.org
25; * https://github.com/FreeRTOS
26; *
27; */
28        RSEG ICODE:CODE
29        CODE32
30
31    EXTERN vTaskSwitchContext
32
33    PUBLIC vPortYieldProcessor
34    PUBLIC vPortStartFirstTask
35
36#include "ISR_Support.h"
37
38;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
39; Starting the first task is just a matter of restoring the context that
40; was created by pxPortInitialiseStack().
41;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
42vPortStartFirstTask:
43    portRESTORE_CONTEXT
44
45;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
46; Manual context switch function.  This is the SWI hander.
47;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
48vPortYieldProcessor:
49    ADD     LR, LR, #4          ; Add 4 to the LR to make the LR appear exactly
50                                ; as if the context was saved during and IRQ
51                                ; handler.
52
53    portSAVE_CONTEXT            ; Save the context of the current task...
54    LDR R0, =vTaskSwitchContext ; before selecting the next task to execute.
55    mov     lr, pc
56    BX R0
57    portRESTORE_CONTEXT         ; Restore the context of the selected task.
58
59
60    END
61