text: /*
   * Copyright (c) 2006-2021, RT-Thread Development Team
   *
   * SPDX-License-Identifier: Apache-2.0
   *
   * Change Logs:
   * Date           Author       Notes
   * 2017/10/15     bernard      implement stdio for armcc.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include <rtthread.h>
  #include "libc.h"
  
  #if defined(RT_USING_DFS) && defined(RT_USING_DFS_DEVFS)
  #include <dfs_posix.h>
  
  #define STDIO_DEVICE_NAME_MAX   32
  
  static int std_fd = -1;
  int libc_stdio_set_console(const char* device_name, int mode)
  {
      int fd;
      char name[STDIO_DEVICE_NAME_MAX];
  
      snprintf(name, sizeof(name) - 1, "/dev/%s", device_name);
      name[STDIO_DEVICE_NAME_MAX - 1] = '\0';
  
      fd = open(name, mode, 0);
      if (fd >= 0)
      {
          if (std_fd >= 0)
          {
              close(std_fd);
          }
          std_fd = fd;
      }
  
      return std_fd;
  }
  
  int libc_stdio_get_console(void)
  {
      return std_fd;
  }
  
  int libc_stdio_read(void *buffer, size_t size)
  {
      if (std_fd >= 0)
      {
          return read(std_fd, buffer, size);
      }
      else
      {
          rt_kprintf("Illegal stdio input!\n");
          return 0;
      }
  }
  
  int libc_stdio_write(const void *buffer, size_t size)
  {
      if (std_fd >= 0)
      {
          return write(std_fd, buffer, size);
      }
      else
      {
          rt_kprintf("Illegal stdio output!\n");
          return size;
      }
  }
  #endif
  