IAR 9.30.1 GD32F427 printf无法打印

最新推荐文章于 2025-03-29 16:43:42 发布

缘来也不错

最新推荐文章于 2025-03-29 16:43:42 发布

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IAR 9.30.1 GD32F427 printf无法打印

由于编译的工程文件存在typeof函数，编译一直不通过：查询得知低版本的IAR不支持typeof()

原因：typeof()是GNU C的关键字，有的编译器支持，有的编译器不支持。因此将低版本替换至高版本iar

低版本的9.10.1工程中可正常打印信息，高版本9.30.1打开该工程无法使用。总结一下方法步骤：

1、打开IAR的安装目录，查找write.c文件 D:\IAR\arm\src\lib\file

2、修改write.c文件，修改以下位置：

（1）将原版本重定义函数复制到write.c文件：（本文以gd为例）

`int fputc(int ch, FILE *f)
{
    usart_data_transmit(USART0, (uint8_t)ch);
    while(RESET == usart_flag_get(USART0, USART_FLAG_TBE));
    return ch;
}`

原write.c文件修改为：

`int MyLowLevelPutchar(int ch);
{
    usart_data_transmit(USART0, (uint8_t)ch);
    while(RESET == usart_flag_get(USART0, USART_FLAG_TBE));
    return ch;
}`

（2）将原函数的if#0 修改为if 1

修改完成后的write.c文件如下：

#include <LowLevelIOInterface.h>
#include "gd32f4xx.h"
#include <stdio.h>

#pragma module_name = "?__write"
#define EVAL_COM1 USART0


int MyLowLevelPutchar(int ch);

int MyLowLevelPutchar(int ch);
{
    usart_data_transmit(EVAL_COM1, (uint8_t)ch);
    while(RESET == usart_flag_get(EVAL_COM1, USART_FLAG_TBE));
    return ch;
}

/*
 * If the __write implementation uses internal buffering, uncomment
 * the following line to ensure that we are called with "buffer" as 0
 * (i.e. flush) when the application terminates.
 */

size_t __write(int handle, const unsigned char * buffer, size_t size)
{
  /* Remove the #if #endif pair to enable the implementation */
#if 1

  size_t nChars = 0;

  if (buffer == 0)
  {
    /*
     * This means that we should flush internal buffers.  Since we
     * don't we just return.  (Remember, "handle" == -1 means that all
     * handles should be flushed.)
     */
    return 0;
  }

  /* This template only writes to "standard out" and "standard err",
   * for all other file handles it returns failure. */
  if (handle != _LLIO_STDOUT && handle != _LLIO_STDERR)
  {
    return _LLIO_ERROR;
  }

  for (/* Empty */; size != 0; --size)
  {
    if (MyLowLevelPutchar(*buffer++) < 0)
    {
      return _LLIO_ERROR;
    }

    ++nChars;
  }

  return nChars;

#else

  /* Always return error code when implementation is disabled. */
  return _LLIO_ERROR;

#endif

}