main.c

针对at91系列的arm的启动代码的编写有一个整体的说明

/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support  -  ROUSSET  -
 * ----------------------------------------------------------------------------
 * Copyright (c) 2006, Atmel Corporation

 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * - Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the disclaimer below in the documentation and/or
 * other materials provided with the distribution.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ----------------------------------------------------------------------------
 * File Name           : main.c
 * Object              :
 * Creation            : ODi Apr 19th 2006
 *-----------------------------------------------------------------------------
 */
#include "include/part.h"
#include "include/main.h"
#include "include/debug.h"
#include "include/dataflash.h"
#include "include/nandflash.h"

/*------------------------------------------------------------------------------*/
/* Function Name       : main							*/
/* Object              : Main function						*/
/* Input Parameters    : none							*/
/* Output Parameters   : True							*/
/*------------------------------------------------------------------------------*/
int main(void)
{
/* ================== 1st step: Hardware Initialization ================= */
	/* Performs the hardware initialization */
#ifdef CFG_HW_INIT
	hw_init();
#endif

/* ==================== 2nd step: Load from media ==================== */
	/* Load from Dataflash in RAM */
#ifdef CFG_DATAFLASH
	load_df(AT91C_SPI_PCS_DATAFLASH, IMG_ADDRESS, IMG_SIZE, JUMP_ADDR);
#endif

	/* Load from Nandflash in RAM */
#ifdef CFG_NANDFLASH
	load_nandflash(IMG_ADDRESS, IMG_SIZE, JUMP_ADDR);
#endif

/* ==================== 3rd step:  Process the Image =================== */
	/* Uncompress the image */
#ifdef GUNZIP
	decompress_image((void *)IMG_ADDRESS, (void *)JUMP_ADDR, IMG_SIZE);	/* NOT IMPLEMENTED YET */
#endif /* GUNZIP */

/* ==================== 4th step: Start the application =================== */
	/* Set linux arguments */
#ifdef LINUX_ARG
	linux_arg(LINUX_ARG);	/* NOT IMPLEMENTED YET */
#endif /* LINUX_ARG */

	/* Jump to the Image Address */
	return JUMP_ADDR;
}