bo_load.c

ARM入门的好帮手.包含了从简单到相对较复杂的程序.

//*----------------------------------------------------------------------------
//*      ATMEL Microcontroller Software Support  -  ROUSSET  -
//*----------------------------------------------------------------------------
//* The software is delivered "AS IS" without warranty or condition of any
//* kind, either express, implied or statutory. This includes without
//* limitation any warranty or condition with respect to merchantability or
//* fitness for any particular purpose, or against the infringements of
//* intellectual property rights of others.
//*----------------------------------------------------------------------------
//* File Name           : bo_load.c
//* Object              : Load program in RAM
//*
//* Imported resources  : init_usart, disable_usart, receive_frame
//* Exported resources  : BootLoad
//*
//* 1.0  06/04/00 JPP    : Creation
//* 2.01 29/05/00 PF     : Clean up
//*----------------------------------------------------------------------------

#include "periph\stdc\std_c.h"
#include "periph\pio\pio.h"
#include "periph\usart\usart.h"
#include "parts\r40807\r40807.h"

#include "at91eb40.h"       /* AT91EB40 description */

/* Hardware description */
#define NB_USART    	2
#define PIO_IRQ0    	9

#define SSRAM_ADDR  	0x02000000
#define BUFFER_SIZE 	0x0FFFF

extern	u_int init_usart ( u_int usart_id, u_int mode, u_int speed, u_int timeguard ) ;
extern	u_int disable_usart ( u_int usart_id ) ;
extern	u_int receive_frame ( u_int usart_id, char *pt_buffer, u_int max_size, u_int timeout ) ;

//*----------------------------------------------------------------------------------
//* Function Name       : BootLoad
//* Object              : Main function of the bootloader
//* Input Parameters    : none
//* Output Parameters   : none
//* Functions called    : init_usart, disable_usart, receive_frame
//*----------------------------------------------------------------------------------
int BootLoad ( void )
//* Begin
{
	u_int	end ;
	u_int	usart_id ;

	StructUSART		*usart0_pt = USART0_BASE ;
	StructUSART		*usart1_pt = USART1_BASE ;

	//* For each USART
   	for (usart_id = 0 ;  usart_id < NB_USART  ;  usart_id ++)
   	{
   	    //* Initialize USART
   	    init_usart (usart_id, US_ASYNC_MODE, (usart_id == 0 ? 18 : 53), 0) ;

		//* Initialize PDC Reception
   	    receive_frame (usart_id, (char *)SSRAM_ADDR, BUFFER_SIZE, 1000 ) ;
	}

    //* Wait for IRQ0 pin asserted
	end = FALSE ;
    while (!end )
	{
		if ((PIO_BASE->PIO_PDSR & SW5)!= 0) end = TRUE ;

		//* Test the End of receive for USART0
		if (( usart0_pt->US_CSR & US_ENDRX ) != 0 )
		{
			usart0_pt->US_RCR = BUFFER_SIZE ;
		}

		//* Test the End of receive for USART1
		if (( usart1_pt->US_CSR & US_ENDRX ) != 0 )
		{
			usart1_pt->US_RCR = BUFFER_SIZE ;
		}
	}

    //* For each USART
    for (usart_id = 0  ;  usart_id < NB_USART  ;  usart_id ++)
    {
        //* Disable USART
        disable_usart (usart_id);
    //* EndFor
    }

    return(SSRAM_ADDR);
//* End
}