1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
/*
* FreeRTOS Kernel V10.1.0
* Copyright (C) 2017 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* 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
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* 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
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* 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
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
#include "FreeRTOSConfig.h"
#include "portasm.h"
.CODE
/*
* The RTOS tick ISR.
*
* If the cooperative scheduler is in use this simply increments the tick
* count.
*
* If the preemptive scheduler is in use a context switch can also occur.
*/
_vTickISR:
portSAVE_CONTEXT
call #_xTaskIncrementTick
cmp.w #0x00, r15
jeq _SkipContextSwitch
call #_vTaskSwitchContext
_SkipContextSwitch:
portRESTORE_CONTEXT
/*-----------------------------------------------------------*/
/*
* Manual context switch called by the portYIELD() macro.
*/
_vPortYield::
/* Mimic an interrupt by pushing the SR. */
push SR
/* Now the SR is stacked we can disable interrupts. */
dint
/* Save the context of the current task. */
portSAVE_CONTEXT
/* Switch to the highest priority task that is ready to run. */
call #_vTaskSwitchContext
/* Restore the context of the new task. */
portRESTORE_CONTEXT
/*-----------------------------------------------------------*/
/*
* Start off the scheduler by initialising the RTOS tick timer, then restoring
* the context of the first task.
*/
_xPortStartScheduler::
/* Setup the hardware to generate the tick. Interrupts are disabled
when this function is called. */
call #_prvSetupTimerInterrupt
/* Restore the context of the first task that is going to run. */
portRESTORE_CONTEXT
/*-----------------------------------------------------------*/
/* Place the tick ISR in the correct vector. */
.VECTORS
.KEEP
ORG TIMERA0_VECTOR
DW _vTickISR
END
|
