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
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
|
/*----------------------------------------------------------------------------
* CMSIS-RTOS - RTX
*----------------------------------------------------------------------------
* Name: HAL_CM0.S
* Purpose: Hardware Abstraction Layer for Cortex-M0
* Rev.: V4.70
*----------------------------------------------------------------------------
*
* Copyright (c) 1999-2009 KEIL, 2009-2013 ARM Germany GmbH
* All rights reserved.
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDERS AND CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*---------------------------------------------------------------------------*/
NAME HAL_CM0.S
#define TCB_TSTACK 40
EXTERN os_flags
EXTERN os_tsk
EXTERN rt_alloc_box
EXTERN rt_free_box
EXTERN rt_stk_check
EXTERN rt_pop_req
EXTERN rt_systick
EXTERN os_tick_irqack
EXTERN SVC_Table
EXTERN SVC_Count
/*----------------------------------------------------------------------------
* Functions
*---------------------------------------------------------------------------*/
SECTION .text:CODE:NOROOT(2)
THUMB
/*--------------------------- rt_set_PSP ------------------------------------*/
; void rt_set_PSP (U32 stack);
PUBLIC rt_set_PSP
rt_set_PSP:
MSR PSP,R0
BX LR
/*--------------------------- rt_get_PSP ------------------------------------*/
; U32 rt_get_PSP (void);
PUBLIC rt_get_PSP
rt_get_PSP:
MRS R0,PSP
BX LR
/*--------------------------- os_set_env ------------------------------------*/
; void os_set_env (void);
/* Switch to Unprivileged/Privileged Thread mode, use PSP. */
PUBLIC os_set_env
os_set_env:
MOV R0,SP /* PSP = MSP */
MSR PSP,R0
LDR R0,=os_flags
LDRB R0,[R0]
LSLS R0,#31
BNE PrivilegedE
MOVS R0,#0x03 /* Unprivileged Thread mode, use PSP */
MSR CONTROL,R0
BX LR
PrivilegedE:
MOVS R0,#0x02 /* Privileged Thread mode, use PSP */
MSR CONTROL,R0
BX LR
/*--------------------------- _alloc_box ------------------------------------*/
; void *_alloc_box (void *box_mem);
/* Function wrapper for Unprivileged/Privileged mode. */
PUBLIC _alloc_box
_alloc_box:
LDR R3,=rt_alloc_box
MOV R12,R3
MRS R3,IPSR
LSLS R3,#24
BNE PrivilegedA
MRS R3,CONTROL
LSLS R3,#31
BEQ PrivilegedA
SVC 0
BX LR
PrivilegedA:
BX R12
/*--------------------------- _free_box -------------------------------------*/
; int _free_box (void *box_mem, void *box);
/* Function wrapper for Unprivileged/Privileged mode. */
PUBLIC _free_box
_free_box:
LDR R3,=rt_free_box
MOV R12,R3
MRS R3,IPSR
LSLS R3,#24
BNE PrivilegedF
MRS R3,CONTROL
LSLS R3,#31
BEQ PrivilegedF
SVC 0
BX LR
PrivilegedF:
BX R12
/*-------------------------- SVC_Handler ------------------------------------*/
; void SVC_Handler (void);
PUBLIC SVC_Handler
SVC_Handler:
MRS R0,PSP /* Read PSP */
LDR R1,[R0,#24] /* Read Saved PC from Stack */
SUBS R1,R1,#2 /* Point to SVC Instruction */
LDRB R1,[R1] /* Load SVC Number */
CMP R1,#0
BNE SVC_User /* User SVC Number > 0 */
MOV LR,R4
LDMIA R0,{R0-R3,R4} /* Read R0-R3,R12 from stack */
MOV R12,R4
MOV R4,LR
BLX R12 /* Call SVC Function */
MRS R3,PSP /* Read PSP */
STMIA R3!,{R0-R2} /* Store return values */
LDR R3,=os_tsk
LDMIA R3!,{R1,R2} /* os_tsk.run, os_tsk.new */
CMP R1,R2
BEQ SVC_Exit /* no task switch */
SUBS R3,#8
CMP R1,#0 /* Runtask deleted? */
BEQ SVC_Next
MRS R0,PSP /* Read PSP */
SUBS R0,R0,#32 /* Adjust Start Address */
STR R0,[R1,#TCB_TSTACK] /* Update os_tsk.run->tsk_stack */
STMIA R0!,{R4-R7} /* Save old context (R4-R7) */
MOV R4,R8
MOV R5,R9
MOV R6,R10
MOV R7,R11
STMIA R0!,{R4-R7} /* Save old context (R8-R11) */
PUSH {R2,R3}
BL rt_stk_check /* Check for Stack overflow */
POP {R2,R3}
SVC_Next:
STR R2,[R3] /* os_tsk.run = os_tsk.new */
LDR R0,[R2,#TCB_TSTACK] /* os_tsk.new->tsk_stack */
ADDS R0,R0,#16 /* Adjust Start Address */
LDMIA R0!,{R4-R7} /* Restore new Context (R8-R11) */
MOV R8,R4
MOV R9,R5
MOV R10,R6
MOV R11,R7
MSR PSP,R0 /* Write PSP */
SUBS R0,R0,#32 /* Adjust Start Address */
LDMIA R0!,{R4-R7} /* Restore new Context (R4-R7) */
SVC_Exit:
MOVS R0,#~0xFFFFFFFD /* Set EXC_RETURN value */
MVNS R0,R0
BX R0 /* RETI to Thread Mode, use PSP */
/*------------------- User SVC ------------------------------*/
SVC_User:
PUSH {R4,LR} /* Save Registers */
LDR R2,=SVC_Count
LDR R2,[R2]
CMP R1,R2
BHI SVC_Done /* Overflow */
LDR R4,=SVC_Table-4
LSLS R1,R1,#2
LDR R4,[R4,R1] /* Load SVC Function Address */
MOV LR,R4
LDMIA R0,{R0-R3,R4} /* Read R0-R3,R12 from stack */
MOV R12,R4
BLX LR /* Call SVC Function */
MRS R4,PSP /* Read PSP */
STMIA R4!,{R0-R3} /* Function return values */
SVC_Done:
POP {R4,PC} /* RETI */
/*-------------------------- PendSV_Handler ---------------------------------*/
; void PendSV_Handler (void);
PUBLIC PendSV_Handler
PendSV_Handler:
BL rt_pop_req
Sys_Switch:
LDR R3,=os_tsk
LDMIA R3!,{R1,R2} /* os_tsk.run, os_tsk.new */
CMP R1,R2
BEQ Sys_Exit /* no task switch */
SUBS R3,#8
MRS R0,PSP /* Read PSP */
SUBS R0,R0,#32 /* Adjust Start Address */
STR R0,[R1,#TCB_TSTACK] /* Update os_tsk.run->tsk_stack */
STMIA R0!,{R4-R7} /* Save old context (R4-R7) */
MOV R4,R8
MOV R5,R9
MOV R6,R10
MOV R7,R11
STMIA R0!,{R4-R7} /* Save old context (R8-R11) */
PUSH {R2,R3}
BL rt_stk_check /* Check for Stack overflow */
POP {R2,R3}
STR R2,[R3] /* os_tsk.run = os_tsk.new */
LDR R0,[R2,#TCB_TSTACK] /* os_tsk.new->tsk_stack */
ADDS R0,R0,#16 /* Adjust Start Address */
LDMIA R0!,{R4-R7} /* Restore new Context (R8-R11) */
MOV R8,R4
MOV R9,R5
MOV R10,R6
MOV R11,R7
MSR PSP,R0 /* Write PSP */
SUBS R0,R0,#32 /* Adjust Start Address */
LDMIA R0!,{R4-R7} /* Restore new Context (R4-R7) */
Sys_Exit:
MOVS R0,#~0xFFFFFFFD /* Set EXC_RETURN value */
MVNS R0,R0
BX R0 /* RETI to Thread Mode, use PSP */
/*-------------------------- SysTick_Handler --------------------------------*/
; void SysTick_Handler (void);
PUBLIC SysTick_Handler
SysTick_Handler:
BL rt_systick
B Sys_Switch
/*-------------------------- OS_Tick_Handler --------------------------------*/
; void OS_Tick_Handler (void);
PUBLIC OS_Tick_Handler
OS_Tick_Handler:
BL os_tick_irqack
BL rt_systick
B Sys_Switch
END
/*----------------------------------------------------------------------------
* end of file
*---------------------------------------------------------------------------*/
|
