原创 HAL的不同方式访问字符器件的空间开销简单比较.(Nios II)

Unix类型

#include "system.h"
#include "fcntl.h"
#include "unistd.h"

int main(void)
{
  int fd; // file descriptor
  char msg[] = "Hello Nios!";
  
  fd = open("/dev/jtag_uart", O_WRONLY);
  write(fd, msg, sizeof(msg)-1);
  close(fd);

  return 0;
}

Info: (hello_nios.elf) 2608 Bytes program size (code + initialized data).
Info:                  8189 KBytes free for stack + heap.

ANSI C

#include "system.h"
#include <stdio.h>

int main (void)
{
  FILE *fp; // file pointer
  char msg[] = "Hello Nios!";
  
  fp = fopen("/dev/jtag_uart", "w");
  fprintf(fp, msg);
  fclose(fp);
  
  return 0;
}

Info: (hello_nios.elf) 43 KBytes program size (code + initialized data).
Info:                  8148 KBytes free for stack + heap.