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
|
;/*
; FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd.
; All rights reserved
;
;
; ***************************************************************************
; * *
; * FreeRTOS tutorial books are available in pdf and paperback. *
; * Complete, revised, and edited pdf reference manuals are also *
; * available. *
; * *
; * Purchasing FreeRTOS documentation will not only help you, by *
; * ensuring you get running as quickly as possible and with an *
; * in-depth knowledge of how to use FreeRTOS, it will also help *
; * the FreeRTOS project to continue with its mission of providing *
; * professional grade, cross platform, de facto standard solutions *
; * for microcontrollers - completely free of charge! *
; * *
; * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
; * *
; * Thank you for using FreeRTOS, and thank you for your support! *
; * *
; ***************************************************************************
;
;
; 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. See the GNU General Public License for
; more details. You should have received a copy of the GNU General Public
; License and the FreeRTOS license exception along with FreeRTOS; if not it
; can be viewed here: http://www.freertos.org/a00114.html and also obtained
; by writing to Richard Barry, contact details for whom are available on the
; FreeRTOS WEB site.
;
; 1 tab == 4 spaces!
;
; http://www.FreeRTOS.org - Documentation, latest information, license and
; contact details.
;
; http://www.SafeRTOS.com - A version that is certified for use in safety
; critical systems.
;
; http://www.OpenRTOS.com - Commercial support, development, porting,
; licensing and training services.
;*/
SYS_MODE EQU 0x1f
SVC_MODE EQU 0x13
IRQ_MODE EQU 0x12
IMPORT ulCriticalNesting
IMPORT pxCurrentTCB
IMPORT ulPortTaskHasFPUContext
IMPORT ulAsmAPIPriorityMask
IMPORT ulICCPMR
MACRO
portSAVE_CONTEXT
; Save the LR and SPSR onto the system mode stack before switching to
; system mode to save the remaining system mode registers
SRSDB sp!, #SYS_MODE
CPS #SYS_MODE
PUSH {R0-R12, R14}
; Push the critical nesting count
LDR R2, =ulCriticalNesting
LDR R1, [R2]
PUSH {R1}
; Does the task have a floating point context that needs saving? If
; ulPortTaskHasFPUContext is 0 then no.
LDR R2, =ulPortTaskHasFPUContext
LDR R3, [R2]
CMP R3, #0
; Save the floating point context, if any
FMRXNE R1, FPSCR
VPUSHNE {D0-D15}
VPUSHNE {D16-D31}
PUSHNE {R1}
; Save ulPortTaskHasFPUContext itself
PUSH {R3}
; Save the stack pointer in the TCB
LDR R0, =pxCurrentTCB
LDR R1, [R0]
STR SP, [R1]
MEND
; /**********************************************************************/
MACRO
portRESTORE_CONTEXT
; Set the SP to point to the stack of the task being restored.
LDR R0, =pxCurrentTCB
LDR R1, [R0]
LDR SP, [R1]
; Is there a floating point context to restore? If the restored
; ulPortTaskHasFPUContext is zero then no.
LDR R0, =ulPortTaskHasFPUContext
POP {R1}
STR R1, [R0]
CMP R1, #0
; Restore the floating point context, if any
POPNE {R0}
VPOPNE {D16-D31}
VPOPNE {D0-D15}
VMSRNE FPSCR, R0
; Restore the critical section nesting depth
LDR R0, =ulCriticalNesting
POP {R1}
STR R1, [R0]
; Ensure the priority mask is correct for the critical nesting depth
LDR R2, =ulICCPMR
CMP R1, #0
MOVEQ R4, #255
LDRNE R4, =ulAsmAPIPriorityMask
STR R4, [r2]
; Restore all system mode registers other than the SP (which is already
; being used)
POP {R0-R12, R14}
; Return to the task code, loading CPSR on the way.
RFEIA sp!
MEND
END
|
