/
irq_cm4f.S
169 lines (133 loc) · 6.58 KB
/
irq_cm4f.S
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
167
168
169
;/*
; * Copyright (c) 2013-2018 Arm Limited. All rights reserved.
; *
; * SPDX-License-Identifier: Apache-2.0
; *
; * Licensed under the Apache License, Version 2.0 (the License); you may
; * not use this file except in compliance with the License.
; * You may obtain a copy of the License at
; *
; * www.apache.org/licenses/LICENSE-2.0
; *
; * Unless required by applicable law or agreed to in writing, software
; * distributed under the License is distributed on an AS IS BASIS, WITHOUT
; * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
; * See the License for the specific language governing permissions and
; * limitations under the License.
; *
; * -----------------------------------------------------------------------------
; *
; * Project: CMSIS-RTOS RTX
; * Title: Cortex-M4F Exception handlers
; *
; * -----------------------------------------------------------------------------
; */
I_T_RUN_OFS EQU 20 ; osRtxInfo.thread.run offset
TCB_SP_OFS EQU 56 ; TCB.SP offset
TCB_SF_OFS EQU 34 ; TCB.stack_frame offset
PRESERVE8
THUMB
AREA |.constdata|, DATA, READONLY
EXPORT irqRtxLib
irqRtxLib DCB 0 ; Non weak library reference
AREA |.text|, CODE, READONLY
SVC_Handler PROC
EXPORT SVC_Handler
IMPORT osRtxUserSVC
IMPORT osRtxInfo
IF :DEF:MPU_LOAD
IMPORT osRtxMpuLoad
ENDIF
TST LR,#0x04 ; Determine return stack from EXC_RETURN bit 2
ITE EQ
MRSEQ R0,MSP ; Get MSP if return stack is MSP
MRSNE R0,PSP ; Get PSP if return stack is PSP
LDR R1,[R0,#24] ; Load saved PC from stack
LDRB R1,[R1,#-2] ; Load SVC number
CBNZ R1,SVC_User ; Branch if not SVC 0
PUSH {R0,LR} ; Save SP and EXC_RETURN
LDM R0,{R0-R3,R12} ; Load function parameters and address from stack
BLX R12 ; Call service function
POP {R12,LR} ; Restore SP and EXC_RETURN
STM R12,{R0-R1} ; Store function return values
SVC_Context
LDR R3,=osRtxInfo+I_T_RUN_OFS; Load address of osRtxInfo.run
LDM R3,{R1,R2} ; Load osRtxInfo.thread.run: curr & next
CMP R1,R2 ; Check if thread switch is required
IT EQ
BXEQ LR ; Exit when threads are the same
CBNZ R1,SVC_ContextSave ; Branch if running thread is not deleted
TST LR,#0x10 ; Check if extended stack frame
BNE SVC_ContextSwitch
#ifdef __FPU_PRESENT
LDR R1,=0xE000EF34 ; FPCCR Address
LDR R0,[R1] ; Load FPCCR
BIC R0,R0,#1 ; Clear LSPACT (Lazy state)
STR R0,[R1] ; Store FPCCR
B SVC_ContextSwitch
#endif
SVC_ContextSave
STMDB R12!,{R4-R11} ; Save R4..R11
#ifdef __FPU_PRESENT
TST LR,#0x10 ; Check if extended stack frame
IT EQ
VSTMDBEQ R12!,{S16-S31} ; Save VFP S16.S31
#endif
STR R12,[R1,#TCB_SP_OFS] ; Store SP
STRB LR, [R1,#TCB_SF_OFS] ; Store stack frame information
SVC_ContextSwitch
STR R2,[R3] ; osRtxInfo.thread.run: curr = next
IF :DEF:MPU_LOAD
PUSH {R2,R3} ; Save registers
MOV R0,R2 ; osRtxMpuLoad parameter
BL osRtxMpuLoad ; Load MPU for next thread
POP {R2,R3} ; Restore registers
ENDIF
SVC_ContextRestore
LDRB R1,[R2,#TCB_SF_OFS] ; Load stack frame information
LDR R0,[R2,#TCB_SP_OFS] ; Load SP
ORR LR,R1,#0xFFFFFF00 ; Set EXC_RETURN
#ifdef __FPU_PRESENT
TST LR,#0x10 ; Check if extended stack frame
IT EQ
VLDMIAEQ R0!,{S16-S31} ; Restore VFP S16..S31
#endif
LDMIA R0!,{R4-R11} ; Restore R4..R11
MSR PSP,R0 ; Set PSP
SVC_Exit
BX LR ; Exit from handler
SVC_User
LDR R2,=osRtxUserSVC ; Load address of SVC table
LDR R3,[R2] ; Load SVC maximum number
CMP R1,R3 ; Check SVC number range
BHI SVC_Exit ; Branch if out of range
PUSH {R0,LR} ; Save SP and EXC_RETURN
LDR R12,[R2,R1,LSL #2] ; Load address of SVC function
LDM R0,{R0-R3} ; Load function parameters from stack
BLX R12 ; Call service function
POP {R12,LR} ; Restore SP and EXC_RETURN
STR R0,[R12] ; Store function return value
BX LR ; Return from handler
ALIGN
ENDP
PendSV_Handler PROC
EXPORT PendSV_Handler
IMPORT osRtxPendSV_Handler
PUSH {R0,LR} ; Save EXC_RETURN
BL osRtxPendSV_Handler ; Call osRtxPendSV_Handler
POP {R0,LR} ; Restore EXC_RETURN
MRS R12,PSP
B SVC_Context
ALIGN
ENDP
SysTick_Handler PROC
EXPORT SysTick_Handler
IMPORT osRtxTick_Handler
PUSH {R0,LR} ; Save EXC_RETURN
BL osRtxTick_Handler ; Call osRtxTick_Handler
POP {R0,LR} ; Restore EXC_RETURN
MRS R12,PSP
B SVC_Context
ALIGN
ENDP
END