alt_flash_open_dev

following is my code:

# include <stdio.h> # include <stdlib.h># include <string.h># include "system.h" # include "altera_avalon_pio_regs.h" # include "alt_types.h" # include "altera_avalon_performance_counter.h"# include "sys/alt_flash.h" # include "sys/alt_flash_dev.h"

int main(void)

{

alt_flash_fd* fd;

//int number_of_regions;

//int block;

//flash_region* regions;

//int ret_code = 0x0;

alt_u8 flashname[30];

strcpy(flashname, "/dev/ext_flash");;

fd = alt_flash_open_dev("/dev/ext_flash");

if (fd)

{

printf(" -Successfully opened %s\n", flashname);

}

else{

printf("The end\n");}

return 0;

}

why the return of alt_flash_open_dev is always error where The end is printed? i am using altera de2 board. 1mb flash, reset vector is set to sdram as well as exception vector.