text: /**
   * \file
   *
   * \brief System-specific implementation of the \ref _read function used by
   *         the standard library.
   *
   * Copyright (c) 2009-2013 Atmel Corporation. All rights reserved.
   *
   * \asf_license_start
   *
   * \page License
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice,
   *    this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * 3. The name of Atmel may not be used to endorse or promote products derived
   *    from this software without specific prior written permission.
   *
   * 4. This software may only be redistributed and used in connection with an
   *    Atmel microcontroller product.
   *
   * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
   * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * \asf_license_stop
   *
   */
  
  #include "compiler.h"
  
  /**
   * \defgroup group_common_utils_stdio Standard I/O (stdio)
   *
   * Common standard I/O driver that implements the stdio
   * read and write functions on AVR and SAM devices.
   *
   * \{
   */
  
  extern volatile void *volatile stdio_base;
  void (*ptr_get)(void volatile*, char*);
  
  
  // IAR common implementation
  #if ( defined(__ICCAVR32__) || defined(__ICCAVR__) || defined(__ICCARM__) )
  
  #include <yfuns.h>
  
  _STD_BEGIN
  
  #pragma module_name = "?__read"
  
  /*! \brief Reads a number of bytes, at most \a size, into the memory area
   *         pointed to by \a buffer.
   *
   * \param handle File handle to read from.
   * \param buffer Pointer to buffer to write read bytes to.
   * \param size Number of bytes to read.
   *
   * \return The number of bytes read, \c 0 at the end of the file, or
   *         \c _LLIO_ERROR on failure.
   */
  size_t __read(int handle, unsigned char *buffer, size_t size)
  {
  	int nChars = 0;
  	// This implementation only reads from stdin.
  	// For all other file handles, it returns failure.
  	if (handle != _LLIO_STDIN) {
  		return _LLIO_ERROR;
  	}
  	for (; size > 0; --size) {
  		ptr_get(stdio_base, (char*)buffer);
  		buffer++;
  		nChars++;
  	}
  	return nChars;
  }
  
  /*! \brief This routine is required by IAR DLIB library since EWAVR V6.10
   * the implementation is empty to be compatible with old IAR version.
   */
  int __close(int handle)
  {
  	UNUSED(handle);
  	return 0;
  }
  
  /*! \brief This routine is required by IAR DLIB library since EWAVR V6.10
   * the implementation is empty to be compatible with old IAR version.
   */
  int remove(const char* val)
  {
  	UNUSED(val);
  	return 0;
  }
  
  /*! \brief This routine is required by IAR DLIB library since EWAVR V6.10
   * the implementation is empty to be compatible with old IAR version.
   */
  long __lseek(int handle, long val, int val2)
  {
  	UNUSED(handle);
  	UNUSED(val2);
  	return val;
  }
  
  _STD_END
  
  // GCC AVR32 and SAM implementation
  #elif (defined(__GNUC__) && !XMEGA && !MEGA) 
  
  int __attribute__((weak))
  _read (int file, char * ptr, int len); // Remove GCC compiler warning
  
  int __attribute__((weak))
  _read (int file, char * ptr, int len)
  {
  	int nChars = 0;
  
  	if (file != 0) {
  		return -1;
  	}
  
  	for (; len > 0; --len) {
  		ptr_get(stdio_base, ptr);
  		ptr++;
  		nChars++;
  	}
  	return nChars;
  }
  
  // GCC AVR implementation
  #elif (defined(__GNUC__) && (XMEGA || MEGA) )
  
  int _read (int *f); // Remove GCC compiler warning
  
  int _read (int *f)
  {
  	char c;
  	ptr_get(stdio_base,&c);
  	return c;
  }
  #endif
  
  /**
   * \}
   */
  
  