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
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
/*
FreeRTOS V7.5.1 - Copyright (C) 2013 Real Time Engineers Ltd.
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
This file is part of the FreeRTOS distribution.
FreeRTOS is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License (version 2) as published by the
Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
>>! NOTE: The modification to the GPL is included to allow you to distribute
>>! a combined work that includes FreeRTOS without being obliged to provide
>>! the source code for proprietary components outside of the FreeRTOS
>>! kernel.
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. Full license text is available from the following
link: http://www.freertos.org/a00114.html
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, books, training, latest versions,
license and Real Time Engineers Ltd. contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
#include <FreeRTOSConfig.h>
/* For backward compatibility, ensure configKERNEL_INTERRUPT_PRIORITY is
defined. The value zero should also ensure backward compatibility.
FreeRTOS.org versions prior to V4.3.0 did not include this definition. */
#ifndef configKERNEL_INTERRUPT_PRIORITY
#define configKERNEL_INTERRUPT_PRIORITY 0
#endif
RSEG CODE:CODE(2)
thumb
EXTERN vPortYieldFromISR
EXTERN pxCurrentTCB
EXTERN vTaskSwitchContext
PUBLIC vSetMSP
PUBLIC xPortPendSVHandler
PUBLIC vPortSVCHandler
PUBLIC vPortStartFirstTask
/*-----------------------------------------------------------*/
vSetMSP
msr msp, r0
bx lr
/*-----------------------------------------------------------*/
xPortPendSVHandler:
mrs r0, psp
ldr r3, =pxCurrentTCB /* Get the location of the current TCB. */
ldr r2, [r3]
subs r0, r0, #32 /* Make space for the remaining low registers. */
str r0, [r2] /* Save the new top of stack. */
stmia r0!, {r4-r7} /* Store the low registers that are not saved automatically. */
mov r4, r8 /* Store the high registers. */
mov r5, r9
mov r6, r10
mov r7, r11
stmia r0!, {r4-r7}
push {r3, r14}
cpsid i
bl vTaskSwitchContext
cpsie i
pop {r2, r3} /* lr goes in r3. r2 now holds tcb pointer. */
ldr r1, [r2]
ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */
adds r0, r0, #16 /* Move to the high registers. */
ldmia r0!, {r4-r7} /* Pop the high registers. */
mov r8, r4
mov r9, r5
mov r10, r6
mov r11, r7
msr psp, r0 /* Remember the new top of stack for the task. */
subs r0, r0, #32 /* Go back for the low registers that are not automatically restored. */
ldmia r0!, {r4-r7} /* Pop low registers. */
bx r3
/*-----------------------------------------------------------*/
vPortSVCHandler;
ldr r3, =pxCurrentTCB /* Restore the context. */
ldr r1, [r3] /* Get the pxCurrentTCB address. */
ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */
adds r0, r0, #16 /* Move to the high registers. */
ldmia r0!, {r4-r7} /* Pop the high registers. */
mov r8, r4
mov r9, r5
mov r10, r6
mov r11, r7
msr psp, r0 /* Remember the new top of stack for the task. */
subs r0, r0, #32 /* Go back for the low registers that are not automatically restored. */
ldmia r0!, {r4-r7} /* Pop low registers. */
mov r1, r14 /* OR R14 with 0x0d. */
movs r0, #0x0d
orrs r1, r0
bx r1
/*-----------------------------------------------------------*/
vPortStartFirstTask
movs r0, #0x00 /* Locate the top of stack. */
ldr r0, [r0]
msr msp, r0 /* Set the msp back to the start of the stack. */
cpsie i /* Globally enable interrupts. */
svc 0 /* System call to start first task. */
nop
END
|
