109 lines
3.0 KiB
C
109 lines
3.0 KiB
C
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/* prep_c.c - full C support initialization */
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/*
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* Copyright (c) 2014 Wind River Systems, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1) Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2) Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* 3) Neither the name of Wind River Systems nor the names of its contributors
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* may be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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DESCRIPTION
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Initialization of full C support: zero the .bss, copy the .data if XIP,
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call _Cstart().
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Stack is available in this module, but not the global data/bss until their
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initialization is performed.
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*/
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#include <stdint.h>
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#include <toolchain.h>
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#include <linker-defs.h>
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/*******************************************************************************
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*
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* bssZero - clear BSS
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*
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* This routine clears the BSS region, so all bytes are 0.
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*
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* RETURNS: N/A
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*/
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static void bssZero(void)
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{
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volatile uint32_t *pBSS = (uint32_t *)&__bss_start;
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unsigned int n;
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for (n = 0; n < (unsigned int)&__bss_num_words; n++) {
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pBSS[n] = 0;
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}
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}
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/*******************************************************************************
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*
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* dataCopy - copy the data section from ROM to RAM
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*
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* This routine copies the data section from ROM to RAM.
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*
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* RETURNS: N/A
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*/
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#ifdef CONFIG_XIP
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static void dataCopy(void)
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{
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volatile uint32_t *pROM = (uint32_t *)&__data_rom_start;
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volatile uint32_t *pRAM = (uint32_t *)&__data_ram_start;
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unsigned int n;
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for (n = 0; n < (unsigned int)&__data_num_words; n++) {
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pRAM[n] = pROM[n];
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}
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}
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#else
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static void dataCopy(void)
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{
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}
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#endif
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extern FUNC_NORETURN void _Cstart(void);
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/*******************************************************************************
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*
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* _PrepC - prepare to and run C code
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*
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* This routine prepares for the execution of and runs C code.
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*
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* RETURNS: N/A
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*/
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void _PrepC(void)
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{
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bssZero();
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dataCopy();
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_Cstart();
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CODE_UNREACHABLE;
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}
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