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/************************************************************************************//**
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* \file         Source\ARMCM3_STM32\GCC\cstart.c
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* \brief        Bootloader C startup source file.
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* \ingroup      Target_ARMCM3_STM32
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* \internal
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*----------------------------------------------------------------------------------------
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*                          C O P Y R I G H T
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*----------------------------------------------------------------------------------------
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*   Copyright (c) 2011  by Feaser    http://www.feaser.com    All rights reserved
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*
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*----------------------------------------------------------------------------------------
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*                            L I C E N S E
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*----------------------------------------------------------------------------------------
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* This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as published by the Free
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* Software Foundation, either version 3 of the License, or (at your option) any later
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* version.
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*
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* OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
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* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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* PURPOSE. See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along with OpenBLT.
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* If not, see <http://www.gnu.org/licenses/>.
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*
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* A special exception to the GPL is included to allow you to distribute a combined work 
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* that includes OpenBLT without being obliged to provide the source code for any 
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* proprietary components. The exception text is included at the bottom of the license
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* file <license.html>.
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* 
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* \endinternal
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****************************************************************************************/
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/****************************************************************************************
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* Include files
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****************************************************************************************/
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#include "boot.h"                                    /* bootloader generic header      */
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/****************************************************************************************
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* External function protoypes
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****************************************************************************************/
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extern int  main(void);
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/****************************************************************************************
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* External data declarations
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****************************************************************************************/
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/* these externals are declared by the linker */
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extern blt_int32u _etext;
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extern blt_int32u _data;
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extern blt_int32u _edata;
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extern blt_int32u _bss;
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extern blt_int32u _ebss;
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extern blt_int32u _estack;
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/************************************************************************************//**
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** \brief     Reset interrupt service routine. Configures the stack, initializes 
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**            RAM and jumps to function main.
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** \return    none.
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**
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****************************************************************************************/
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void reset_handler(void)
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{
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  blt_int32u *pSrc, *pDest;
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  /* disable interrupts first */
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  __asm("    cpsid     i");
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  /* copy the data segment initializers from flash to SRAM */
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  pSrc = &_etext;
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  for(pDest = &_data; pDest < &_edata; )
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  {
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    *pDest++ = *pSrc++;
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  }
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  /* zero fill the bss segment. this is done with inline assembly since this will 
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   * clear the value of pDest if it is not kept in a register.
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   */
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  __asm("    ldr     r0, =_bss\n"
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        "    ldr     r1, =_ebss\n"
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        "    mov     r2, #0\n"
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        "    .thumb_func\n"
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        "zero_loop:\n"
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        "        cmp     r0, r1\n"
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        "        it      lt\n"
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        "        strlt   r2, [r0], #4\n"
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        "        blt     zero_loop");
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  /* start the software application by calling its entry point */
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  main();
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} /*** end of reset_handler ***/
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/************************************ end of cstart.c **********************************/