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
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
|
/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012,2013 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file ARMCMx/GCC/crt0.c
* @brief Generic GCC Cortex-Mx startup file.
*
* @addtogroup ARMCMx_GCC_STARTUP
* @{
*/
#include <stdint.h>
#if !defined(FALSE)
#define FALSE 0
#endif
#if !defined(TRUE)
#define TRUE (!FALSE)
#endif
#define SCB_CPACR *((uint32_t *)0xE000ED88U)
#define SCB_FPCCR *((uint32_t *)0xE000EF34U)
#define SCB_FPDSCR *((uint32_t *)0xE000EF3CU)
#define FPCCR_ASPEN (0x1U << 31)
#define FPCCR_LSPEN (0x1U << 30)
typedef void (*funcp_t)(void);
typedef funcp_t * funcpp_t;
#define SYMVAL(sym) (uint32_t)(((uint8_t *)&(sym)) - ((uint8_t *)0))
/*
* Area fill code, it is a macro because here functions cannot be called
* until stacks are initialized.
*/
#define fill32(start, end, filler) { \
uint32_t *p1 = (start); \
uint32_t *p2 = (end); \
while (p1 < p2) \
*p1++ = (filler); \
}
/*===========================================================================*/
/**
* @name Startup settings
* @{
*/
/*===========================================================================*/
/**
* @brief Control special register initialization value.
* @details The system is setup to run in privileged mode using the PSP
* stack (dual stack mode).
*/
#if !defined(CRT0_CONTROL_INIT) || defined(__DOXYGEN__)
#define CRT0_CONTROL_INIT 0x00000002
#endif
/**
* @brief Stack segments initialization switch.
*/
#if !defined(CRT0_STACKS_FILL_PATTERN) || defined(__DOXYGEN__)
#define CRT0_STACKS_FILL_PATTERN 0x55555555
#endif
/**
* @brief Stack segments initialization switch.
*/
#if !defined(CRT0_INIT_STACKS) || defined(__DOXYGEN__)
#define CRT0_INIT_STACKS TRUE
#endif
/**
* @brief DATA segment initialization switch.
*/
#if !defined(CRT0_INIT_DATA) || defined(__DOXYGEN__)
#define CRT0_INIT_DATA TRUE
#endif
/**
* @brief BSS segment initialization switch.
*/
#if !defined(CRT0_INIT_BSS) || defined(__DOXYGEN__)
#define CRT0_INIT_BSS TRUE
#endif
/**
* @brief Constructors invocation switch.
*/
#if !defined(CRT0_CALL_CONSTRUCTORS) || defined(__DOXYGEN__)
#define CRT0_CALL_CONSTRUCTORS TRUE
#endif
/**
* @brief Destructors invocation switch.
*/
#if !defined(CRT0_CALL_DESTRUCTORS) || defined(__DOXYGEN__)
#define CRT0_CALL_DESTRUCTORS TRUE
#endif
/** @} */
/*===========================================================================*/
/**
* @name Symbols from the scatter file
*/
/*===========================================================================*/
/**
* @brief Main stack lower boundary.
* @details This symbol must be exported by the linker script and represents
* the main stack lower boundary.
*/
extern uint32_t __main_stack_base__;
/**
*
* @brief Main stack initial position.
* @details This symbol must be exported by the linker script and represents
* the main stack initial position.
*/
extern uint32_t __main_stack_end__;
/**
* @brief Process stack lower boundary.
* @details This symbol must be exported by the linker script and represents
* the process stack lower boundary.
*/
extern uint32_t __process_stack_base__;
/**
* @brief Process stack initial position.
* @details This symbol must be exported by the linker script and represents
* the process stack initial position.
*/
extern uint32_t __process_stack_end__;
/**
* @brief ROM image of the data segment start.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern uint32_t _textdata;
/**
* @brief Data segment start.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern uint32_t _data;
/**
* @brief Data segment end.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern uint32_t _edata;
/**
* @brief BSS segment start.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern uint32_t _bss_start;
/**
* @brief BSS segment end.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern uint32_t _bss_end;
/**
* @brief Constructors table start.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern funcp_t __init_array_start;
/**
* @brief Constructors table end.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern funcp_t __init_array_end;
/**
* @brief Destructors table start.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern funcp_t __fini_array_start;
/**
* @brief Destructors table end.
* @pre The symbol must be aligned to a 32 bits boundary.
*/
extern funcp_t __fini_array_end;
/** @} */
/**
* @brief Application @p main() function.
*/
extern void main(void);
/**
* @brief Early initialization.
* @details This hook is invoked immediately after the stack initialization
* and before the DATA and BSS segments initialization. The
* default behavior is to do nothing.
* @note This function is a weak symbol.
*/
#if !defined(__DOXYGEN__)
__attribute__((weak))
#endif
void __early_init(void) {}
/**
* @brief Late initialization.
* @details This hook is invoked after the DATA and BSS segments
* initialization and before any static constructor. The
* default behavior is to do nothing.
* @note This function is a weak symbol.
*/
#if !defined(__DOXYGEN__)
__attribute__((weak))
#endif
void __late_init(void) {}
/**
* @brief Default @p main() function exit handler.
* @details This handler is invoked or the @p main() function exit. The
* default behavior is to enter an infinite loop.
* @note This function is a weak symbol.
*/
#if !defined(__DOXYGEN__)
__attribute__((noreturn, weak))
#endif
void _default_exit(void) {
while (1)
;
}
/**
* @brief Reset vector.
*/
#if !defined(__DOXYGEN__)
__attribute__((naked))
#endif
void Reset_Handler(void) {
uint32_t psp, reg;
/* Process Stack initialization, it is allocated starting from the
symbol __process_stack_end__ and its lower limit is the symbol
__process_stack_base__.*/
asm volatile ("cpsid i");
psp = SYMVAL(__process_stack_end__);
asm volatile ("msr PSP, %0" : : "r" (psp));
#if CORTEX_USE_FPU
/* Initializing the FPU context save in lazy mode.*/
SCB_FPCCR = FPCCR_ASPEN | FPCCR_LSPEN;
/* CP10 and CP11 set to full access.*/
SCB_CPACR |= 0x00F00000;
/* FPSCR and FPDSCR initially zero.*/
reg = 0;
asm volatile ("vmsr FPSCR, %0" : : "r" (reg) : "memory");
SCB_FPDSCR = reg;
/* CPU mode initialization, enforced FPCA bit.*/
reg = CRT0_CONTROL_INIT | 4;
#else
/* CPU mode initialization.*/
reg = CRT0_CONTROL_INIT;
#endif
asm volatile ("msr CONTROL, %0" : : "r" (reg));
asm volatile ("isb");
#if CRT0_INIT_STACKS
/* Main and Process stacks initialization.*/
fill32(&__main_stack_base__,
&__main_stack_end__,
CRT0_STACKS_FILL_PATTERN);
fill32(&__process_stack_base__,
&__process_stack_end__,
CRT0_STACKS_FILL_PATTERN);
#endif
/* Early initialization hook invocation.*/
__early_init();
#if CRT0_INIT_DATA
/* DATA segment initialization.*/
{
uint32_t *tp, *dp;
tp = &_textdata;
dp = &_data;
while (dp < &_edata)
*dp++ = *tp++;
}
#endif
#if CRT0_INIT_BSS
/* BSS segment initialization.*/
fill32(&_bss_start, &_bss_end, 0);
#endif
/* Late initialization hook invocation.*/
__late_init();
#if CRT0_CALL_CONSTRUCTORS
/* Constructors invocation.*/
{
funcpp_t fpp = &__init_array_start;
while (fpp < &__init_array_end) {
(*fpp)();
fpp++;
}
}
#endif
/* Invoking application main() function.*/
main();
#if CRT0_CALL_DESTRUCTORS
/* Destructors invocation.*/
{
funcpp_t fpp = &__fini_array_start;
while (fpp < &__fini_array_end) {
(*fpp)();
fpp++;
}
}
#endif
/* Invoking the exit handler.*/
_default_exit();
}
/** @} */
|
