text: /* Arduino SdFat Library
   * Copyright (C) 2008 by William Greiman
   *
   * This file is part of the Arduino SdFat Library
   *
   * This Library is free software: you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * This Library is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
  
   * You should have received a copy of the GNU General Public License
   * along with the Arduino SdFat Library.  If not, see
   * <http://www.gnu.org/licenses/>.
   */
  #ifndef SdFatUtil_h
  #define SdFatUtil_h
  /**
   * \file
   * Useful utility functions.
   */
  #include <Arduino.h>
  #ifdef __AVR__
  #include <avr/pgmspace.h>
  /** Store and print a string in flash memory.*/
  #define PgmPrint(x) SerialPrint_P(PSTR(x))
  /** Store and print a string in flash memory followed by a CR/LF.*/
  #define PgmPrintln(x) SerialPrintln_P(PSTR(x))
  /** Defined so doxygen works for function definitions. */
  #endif
  #define NOINLINE __attribute__((noinline,unused))
  #define UNUSEDOK __attribute__((unused))
  //------------------------------------------------------------------------------
  /** Return the number of bytes currently free in RAM. */
  static UNUSEDOK int FreeRam(void) {
    extern int  __bss_end;
    extern int* __brkval;
    int free_memory;
    if (reinterpret_cast<int>(__brkval) == 0) {
      // if no heap use from end of bss section
      free_memory = reinterpret_cast<int>(&free_memory)
                    - reinterpret_cast<int>(&__bss_end);
    } else {
      // use from top of stack to heap
      free_memory = reinterpret_cast<int>(&free_memory)
                    - reinterpret_cast<int>(__brkval);
    }
    return free_memory;
  }
  #ifdef __AVR__
  //------------------------------------------------------------------------------
  /**
   * %Print a string in flash memory to the serial port.
   *
   * \param[in] str Pointer to string stored in flash memory.
   */
  static NOINLINE void SerialPrint_P(PGM_P str) {
    for (uint8_t c; (c = pgm_read_byte(str)); str++) Serial.write(c);
  }
  //------------------------------------------------------------------------------
  /**
   * %Print a string in flash memory followed by a CR/LF.
   *
   * \param[in] str Pointer to string stored in flash memory.
   */
  static NOINLINE void SerialPrintln_P(PGM_P str) {
    SerialPrint_P(str);
    Serial.println();
  }
  #endif  // __AVR__
  #endif  // #define SdFatUtil_h
  