xref: /Kernel-v10.6.2/portable/CCS/MSP430X/portext.asm (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
29; * The definition of the "register test" tasks, as described at the top of
30; * main.c
31
32    .include data_model.h
33
34    .global xTaskIncrementTick
35    .global vTaskSwitchContext
36    .global vPortSetupTimerInterrupt
37    .global pxCurrentTCB
38    .global usCriticalNesting
39
40    .def vPortPreemptiveTickISR
41    .def vPortCooperativeTickISR
42    .def vPortYield
43    .def xPortStartScheduler
44
45;-----------------------------------------------------------
46
47portSAVE_CONTEXT .macro
48
49    ;Save the remaining registers.
50    pushm_x #12, r15
51    movx.w   &usCriticalNesting, r14
52    push_x r14
53    mov_x   &pxCurrentTCB, r12
54    mov_x   sp, 0( r12 )
55    .endm
56;-----------------------------------------------------------
57
58portRESTORE_CONTEXT .macro
59
60    mov_x   &pxCurrentTCB, r12
61    mov_x   @r12, sp
62    pop_x   r15
63    movx.w   r15, &usCriticalNesting
64    popm_x  #12, r15
65    nop
66    pop.w   sr
67    nop
68    ret_x
69    .endm
70;-----------------------------------------------------------
71
72;*
73;* The RTOS tick ISR.
74;*
75;* If the cooperative scheduler is in use this simply increments the tick
76;* count.
77;*
78;* If the preemptive scheduler is in use a context switch can also occur.
79;*/
80
81    .text
82    .align 2
83
84vPortPreemptiveTickISR: .asmfunc
85
86    ; The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs
87    ;to save it manually before it gets modified (interrupts get disabled).
88    push.w sr
89    portSAVE_CONTEXT
90
91    call_x  #xTaskIncrementTick
92    call_x  #vTaskSwitchContext
93
94    portRESTORE_CONTEXT
95    .endasmfunc
96;-----------------------------------------------------------
97
98    .align 2
99
100vPortCooperativeTickISR: .asmfunc
101
102    ; The sr is not saved in portSAVE_CONTEXT() because vPortYield() needs
103    ;to save it manually before it gets modified (interrupts get disabled).
104    push.w sr
105    portSAVE_CONTEXT
106
107    call_x  #xTaskIncrementTick
108
109    portRESTORE_CONTEXT
110
111    .endasmfunc
112;-----------------------------------------------------------
113
114;
115; Manual context switch called by the portYIELD() macro.
116;
117
118    .align 2
119
120vPortYield: .asmfunc
121
122    ; The sr needs saving before it is modified.
123    push.w  sr
124
125    ; Now the SR is stacked we can disable interrupts.
126    dint
127    nop
128
129    ; Save the context of the current task.
130    portSAVE_CONTEXT
131
132    ; Select the next task to run.
133    call_x  #vTaskSwitchContext
134
135    ; Restore the context of the new task.
136    portRESTORE_CONTEXT
137    .endasmfunc
138;-----------------------------------------------------------
139
140
141;
142; Start off the scheduler by initialising the RTOS tick timer, then restoring
143; the context of the first task.
144;
145
146    .align 2
147
148xPortStartScheduler: .asmfunc
149
150    ; Setup the hardware to generate the tick.  Interrupts are disabled
151    ; when this function is called.
152    call_x  #vPortSetupTimerInterrupt
153
154    ; Restore the context of the first task that is going to run.
155    portRESTORE_CONTEXT
156    .endasmfunc
157;-----------------------------------------------------------
158
159    .end
160