code_to_spi.c

此文档为采用FPGA实现的以太网MAC层

// code_to_asmi.c
// Jeremy Fox, Altera UK
// 4/16/03

// Use this file to copy code from a RAM buffer into the EPCS4 flash device on the Nios cyclone
// development board.  This code defaults to copying 0x10000 bytes or code from 0x00800000 (which
// is assumed to be SRAM) to the ASMI device.  Other buffer locations can be chosen if desired by
// modifying the buffer_base #define to a different memory region.
//
// Important things to NOTE:
//
// 1) Before downloading this code to the dev board you should have the code that you want to store
// in the ASMI flash device already loaded into memory at the address indicated by the "buffer_base" 
// #define in this file.
//
// 2) When compiling this code it would be wise to use the nb -b option and have it compiled somewhere
// other than the default base address of 0x00800000 as that is where the code we are going to copy
// to the ASMI is assumed to be.  A likely place to run this code would be from SDRAM, ie..
// use nb -b 0x01000000 code_to_asmi.c


#include "excalibur.h"
#include <stdio.h>
#include "asmi_spi.h"

extern int nr_jumptostart;

unsigned char* error_string(int error_code)
{
  switch (error_code)
  {
    case na_asmi_success: return "na_asmi_success";
    case na_asmi_err_device_not_present: return "na_asmi_err_device_not_present";
    case na_asmi_err_device_not_ready: return "na_asmi_err_device_not_ready";
    case na_asmi_err_timedout: return "na_asmi_err_timedout";
    case na_asmi_err_write_failed: return "na_asmi_err_write_failed";
    case na_asmi_invalid_config: return "na_asmi_invalid_config";
  }

  return "unknown error code";
}


int main(void)
{
	int s = 0;

	volatile char buf[16];

	for (s=0;s<16;s++) buf[s]=s*3;

  // write the code and the header to the ASMI flash
  //User code goes from offset 0 to offset na_sram_size - 0x1000
	printf("Program base is at %X\n",&nr_jumptostart);

  printf("Erasing Flash\n");
  s = nr_spi_erase_bulk();
  if (na_asmi_success != s)
  {
    printf("nr_asmi_erase_bulk() failed ('%s').\n\004", error_string(s));
    return 0;
  }


  printf("Writing user code from RAM address %X to Flash address %X\n",usercode_base,flash_base);
  printf("Code size: %X\n",usercode_size);
  s = nr_spi_write_buffer(flash_base, usercode_size, usercode_base); 
  
  if (na_asmi_success != s)
  {
    printf("nr_spi_write_buffer() failed ('%s').\n\004", error_string(s));
    return 0;
  }

  printf("Writing trailing header\n");
  s = nr_spi_write_buffer(flash_base+usercode_size, 0x10, buf); 
  if (na_asmi_success != s)
  {
    printf("nr_spi_write_buffer() failed ('%s').\n\004", error_string(s));
    return 0;
  }


  // read back the header just to check that I got written to the ASMI properly.
  printf("reading back data header...\n");
  s = nr_spi_read_buffer(flash_base+usercode_size, 16, buf);
  printf("0x%X\n" ,buf[0]);
  printf("0x%X\n" ,buf[4]);
  printf("0x%X\n" ,buf[8]);
  printf("0x%X\n" ,buf[12]);


  if (na_asmi_success != s)
  {
    printf("nr_spi_read_buffer() failed ('%s').\n\004", error_string(s));
    return 0;
  }
	return 0;
}

// end of file