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/* write-uart.c. Implementation of the _write syscall for newlib with UART
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Copyright (C) 2004, Jacob Bower
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Copyright (C) 2010, Embecosm Limited <info@embecosm.com>
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Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>
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This file is part of Newlib.
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The original work by Jacob Bower is provided as-is without any kind of
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warranty. Use it at your own risk!
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All subsequent work is bound by version 3 of the GPL as follows.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3 of the License, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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You should have received a copy of the GNU General Public License along
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with this program. If not, see <http:#www.gnu.org/licenses/>. */
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/* -------------------------------------------------------------------------- */
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/* This program is commented throughout in a fashion suitable for processing
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with Doxygen. */
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/* -------------------------------------------------------------------------- */
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#include <errno.h>
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#include <unistd.h>
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#include "uart.h"
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extern int errno;
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/* -------------------------------------------------------------------------- */
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/*!Write a single character to standard output for the UART
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@param[in] c The character to write */
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/* -------------------------------------------------------------------------- */
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static void
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outbyte (char c)
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{
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if ('\n' == c)
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{
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_uart_putc ('\r');
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}
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_uart_putc (c);
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} /* outbyte () */
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/* -------------------------------------------------------------------------- */
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/*!Write a buffer to a file.
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Only output to stdout or stderr is supported, and both of those are
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directed to the single output stream.
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Remember that this function is *not* reentrant, so no static state should
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be held.
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@param[in] file The fileno for output.
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@param[in] buf The bytes to write.
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@param[in] nbytes The number of bytes to write.
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@return The number of bytes written on success, or -1 with an error code
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in the global variable errno on failure. */
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/* -------------------------------------------------------------------------- */
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int
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_write (int file,
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char *buf,
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int nbytes)
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{
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int i;
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/* We only handle stdout and stderr */
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if ((file != STDOUT_FILENO) && (file != STDERR_FILENO))
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{
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errno = EBADF;
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return -1;
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}
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/* Output character at at time */
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for (i = 0; i < nbytes; i++)
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{
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outbyte (buf[i]);
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}
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return nbytes;
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} /* _write () */
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