/* read-uart.c. Implementation of the _read syscall for newlib with UART.
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/* read-uart.c. Implementation of the _read syscall for newlib with UART.
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Copyright (C) 2004, Jacob Bower
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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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Copyright (C) 2010, Embecosm Limited <info@embecosm.com>
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Contributor Jeremy Bennett <jeremy.bennett@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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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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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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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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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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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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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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Software Foundation; either version 3 of the License, or (at your option)
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any later version.
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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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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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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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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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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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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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with this program. If not, see <http:#www.gnu.org/licenses/>. */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/* This program is commented throughout in a fashion suitable for processing
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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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with Doxygen. */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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#include <errno.h>
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#include <errno.h>
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#include <unistd.h>
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#include <unistd.h>
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extern int errno;
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extern int errno;
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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/*!Read from a file with a UART.
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/*!Read from a file with a UART.
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We only support reading from stdin.
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We only support reading from stdin.
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Remember that this function is *not* reentrant, so no static state should
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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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be held.
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@param[in] file The fileno to read.
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@param[in] file The fileno to read.
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@param[in] buf Buffer into which to read.
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@param[in] buf Buffer into which to read.
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@param[in] len Number of bytes to read.
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@param[in] len Number of bytes to read.
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@return number of bytes read if the file is stdin, otherwise -1 to
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@return number of bytes read if the file is stdin, otherwise -1 to
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indicate failure, with an error code in the global variable
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indicate failure, with an error code in the global variable
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errno. */
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errno. */
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/* -------------------------------------------------------------------------- */
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/* -------------------------------------------------------------------------- */
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int
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int
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_read (int file,
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_read (int file,
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char *buf,
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char *buf,
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int len)
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int len)
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{
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{
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if (STDIN_FILENO == file)
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if (STDIN_FILENO == file)
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{
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{
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int i;
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int i;
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for (i = 0; i < len; i++)
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for (i = 0; i < len; i++)
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{
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{
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buf[i] = _uart_getc ();
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buf[i] = _uart_getc ();
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#ifdef UART_AUTO_ECHO
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#ifdef UART_AUTO_ECHO
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_uart_putc (buf[i]);
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_uart_putc (buf[i]);
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#endif
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#endif
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if (('\n' == buf[i]) || ('\r' == buf[i]))
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/* Return partial buffer if we get EOL */
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if ('\n' == buf[i])
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{
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{
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buf[i] = 0; /* End of string */
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return i;
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return i;
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}
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}
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}
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}
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return i; /* Filled the buffer */
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return i; /* Filled the buffer */
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}
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}
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else
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else
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{
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{
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errno = EBADF;
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errno = EBADF;
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return -1;
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return -1;
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}
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}
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} /* _read () */
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} /* _read () */
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