/* ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010, 2011,2012 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 . --- A special exception to the GPL can be applied should you wish to distribute a combined work that includes ChibiOS/RT, without being obliged to provide the source code for any proprietary components. See the file exception.txt for full details of how and when the exception can be applied. */ /** * @file ARMCMx/crt0.c * @brief Generic ARMvx-M (Cortex-M0/M1/M3/M4) startup file for ChibiOS/RT. * * @addtogroup ARMCMx_STARTUP * @{ */ #include "ch.h" 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__((weak, naked)) #endif void _default_exit(void) { while (1) ; } /** * @brief Reset vector. */ #if !defined(__DOXYGEN__) __attribute__((naked)) #endif void ResetHandler(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(); } /** @} */