amiro-blt / Target / Source / ARMCM4_STM32 / GCC / cstart.c @ 19d9fea2
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| 1 | 69661903 | Thomas Schöpping | /************************************************************************************//** |
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| 2 | * \file Source\ARMCM4_STM32\GCC\cstart.c
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| 3 | * \brief Bootloader C startup source file.
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| 4 | * \ingroup Target_ARMCM4_STM32
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| 5 | * \internal
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| 6 | *----------------------------------------------------------------------------------------
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| 7 | * C O P Y R I G H T
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| 8 | *----------------------------------------------------------------------------------------
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| 9 | * Copyright (c) 2013 by Feaser http://www.feaser.com All rights reserved
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| 10 | *
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| 11 | *----------------------------------------------------------------------------------------
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| 12 | * L I C E N S E
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| 13 | *----------------------------------------------------------------------------------------
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| 14 | * This file is part of OpenBLT. OpenBLT is free software: you can redistribute it and/or
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| 15 | * modify it under the terms of the GNU General Public License as published by the Free
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| 16 | * Software Foundation, either version 3 of the License, or (at your option) any later
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| 17 | * version.
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| 18 | *
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| 19 | * OpenBLT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
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| 20 | * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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| 21 | * PURPOSE. See the GNU General Public License for more details.
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| 22 | *
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| 23 | * You should have received a copy of the GNU General Public License along with OpenBLT.
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| 24 | * If not, see <http://www.gnu.org/licenses/>.
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| 25 | *
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| 26 | * A special exception to the GPL is included to allow you to distribute a combined work
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| 27 | * that includes OpenBLT without being obliged to provide the source code for any
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| 28 | * proprietary components. The exception text is included at the bottom of the license
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| 29 | * file <license.html>.
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| 30 | *
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| 31 | * \endinternal
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| 32 | ****************************************************************************************/
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| 33 | |||
| 34 | /****************************************************************************************
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| 35 | * Include files
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| 36 | ****************************************************************************************/
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| 37 | #include "boot.h" /* bootloader generic header */ |
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| 38 | |||
| 39 | |||
| 40 | /****************************************************************************************
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| 41 | * External function protoypes
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| 42 | ****************************************************************************************/
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| 43 | extern int main(void); |
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| 44 | |||
| 45 | |||
| 46 | /****************************************************************************************
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| 47 | * External data declarations
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| 48 | ****************************************************************************************/
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| 49 | /* these externals are declared by the linker */
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| 50 | extern blt_int32u _etext;
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| 51 | extern blt_int32u _data;
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| 52 | extern blt_int32u _edata;
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| 53 | extern blt_int32u _bss;
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| 54 | extern blt_int32u _ebss;
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| 55 | extern blt_int32u _estack;
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| 56 | |||
| 57 | |||
| 58 | /************************************************************************************//** |
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| 59 | ** \brief Reset interrupt service routine. Configures the stack, initializes
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| 60 | ** RAM and jumps to function main.
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| 61 | ** \return none.
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| 62 | **
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| 63 | ****************************************************************************************/
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| 64 | void reset_handler(void) |
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| 65 | {
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| 66 | blt_int32u *pSrc, *pDest; |
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| 67 | |||
| 68 | /* disable interrupts first */
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| 69 | __asm(" cpsid i");
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| 70 | /* copy the data segment initializers from flash to SRAM */
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| 71 | pSrc = &_etext; |
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| 72 | for(pDest = &_data; pDest < &_edata; )
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| 73 | {
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| 74 | *pDest++ = *pSrc++; |
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| 75 | } |
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| 76 | /* zero fill the bss segment. this is done with inline assembly since this will
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| 77 | * clear the value of pDest if it is not kept in a register.
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| 78 | */
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| 79 | __asm(" ldr r0, =_bss\n"
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| 80 | " ldr r1, =_ebss\n"
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| 81 | " mov r2, #0\n"
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| 82 | " .thumb_func\n"
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| 83 | "zero_loop:\n"
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| 84 | " cmp r0, r1\n"
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| 85 | " it lt\n"
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| 86 | " strlt r2, [r0], #4\n"
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| 87 | " blt zero_loop");
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| 88 | /* start the software application by calling its entry point */
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| 89 | main(); |
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| 90 | } /*** end of reset_handler ***/
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| 91 | |||
| 92 | |||
| 93 | /************************************ end of cstart.c **********************************/ |