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/* write-uart.c. Implementation of the _write syscall for newlib with UART

   Copyright (C) 2004, Jacob Bower

   Copyright (C) 2010, Embecosm Limited <info@embecosm.com>

   Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>

   This file is part of Newlib.

   The original work by Jacob Bower is provided as-is without any kind of

   warranty. Use it at your own risk!

   All subsequent work is bound by version 3 of the GPL as follows.

   This program 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 program 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 this program.  If not, see <http:#www.gnu.org/licenses/>.             */

/* -------------------------------------------------------------------------- */

/* This program is commented throughout in a fashion suitable for processing

   with Doxygen.                                                              */

/* -------------------------------------------------------------------------- */

#include <errno.h>

#include <unistd.h>

#include "uart.h"

#undef errno

extern int  errno;

/* -------------------------------------------------------------------------- */

/*!Write a single character to standard output for the UART

   @param[in] c  The character to write                                       */

/* -------------------------------------------------------------------------- */

static void

outbyte (char  c)

{

  _uart_putc (c);

}       /* outbyte () */

/* -------------------------------------------------------------------------- */

/*!Write a buffer to a file.

   Only output to stdout or stderr is supported, and both of those are

   directed to the single output stream.

   Remember that this function is *not* reentrant, so no static state should

   be held.

   @param[in] file  The fileno for output.

   @param[in] buf   The bytes to write.

   @param[in] nbytes  The number of bytes to write.

   @return  The number of bytes written on success, or -1 with an error code

            in the global variable errno on failure.                          */

/* -------------------------------------------------------------------------- */

int

_write (int   file,

        char *buf,

        int   nbytes)

{

  int i;

  /* We only handle stdout and stderr */

  if ((file != STDOUT_FILENO) && (file != STDERR_FILENO))

    {

      errno = EBADF;

      return -1;

    }

  /* Output character at at time */

  for (i = 0; i < nbytes; i++)

    {

      outbyte (buf[i]);

    }

  return nbytes;

}       /* _write () */