| 1 |
180 |
jeremybenn |
/* lseek-uart.c. Implementation of the _lseek syscall for newlib with UART
|
| 2 |
|
|
|
| 3 |
|
|
Copyright (C) 2004, Jacob Bower
|
| 4 |
|
|
Copyright (C) 2010, Embecosm Limited <info@embecosm.com>
|
| 5 |
|
|
|
| 6 |
|
|
Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>
|
| 7 |
|
|
|
| 8 |
|
|
This file is part of Newlib.
|
| 9 |
|
|
|
| 10 |
|
|
The original work by Jacob Bower is provided as-is without any kind of
|
| 11 |
|
|
warranty. Use it at your own risk!
|
| 12 |
|
|
|
| 13 |
|
|
All subsequent work is bound by version 3 of the GPL as follows.
|
| 14 |
|
|
|
| 15 |
|
|
This program is free software; you can redistribute it and/or modify it
|
| 16 |
|
|
under the terms of the GNU General Public License as published by the Free
|
| 17 |
|
|
Software Foundation; either version 3 of the License, or (at your option)
|
| 18 |
|
|
any later version.
|
| 19 |
|
|
|
| 20 |
|
|
This program is distributed in the hope that it will be useful, but WITHOUT
|
| 21 |
|
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
| 22 |
|
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
| 23 |
|
|
more details.
|
| 24 |
|
|
|
| 25 |
|
|
You should have received a copy of the GNU General Public License along
|
| 26 |
|
|
with this program. If not, see <http:#www.gnu.org/licenses/>. */
|
| 27 |
|
|
/* -------------------------------------------------------------------------- */
|
| 28 |
|
|
/* This program is commented throughout in a fashion suitable for processing
|
| 29 |
|
|
with Doxygen. */
|
| 30 |
|
|
/* -------------------------------------------------------------------------- */
|
| 31 |
|
|
|
| 32 |
|
|
#include <errno.h>
|
| 33 |
|
|
#include <unistd.h>
|
| 34 |
|
|
|
| 35 |
|
|
|
| 36 |
198 |
jeremybenn |
#undef errno
|
| 37 |
180 |
jeremybenn |
extern int errno;
|
| 38 |
|
|
|
| 39 |
|
|
|
| 40 |
|
|
/* -------------------------------------------------------------------------- */
|
| 41 |
|
|
/*!Set a position in a file when using a UART.
|
| 42 |
|
|
|
| 43 |
|
|
We only support stdin, stdout and stderr for which positioning is always to
|
| 44 |
|
|
offset 0.
|
| 45 |
|
|
|
| 46 |
|
|
Remember that this function is *not* reentrant, so no static state should
|
| 47 |
|
|
be held.
|
| 48 |
|
|
|
| 49 |
|
|
@param[in] file The fileno to lseek.
|
| 50 |
|
|
@param[in] offset The desired offset.
|
| 51 |
|
|
@param[in] whence Where to lseek from.
|
| 52 |
|
|
|
| 53 |
|
|
@return 0, indicating the offset achieved. */
|
| 54 |
|
|
/* -------------------------------------------------------------------------- */
|
| 55 |
|
|
int
|
| 56 |
|
|
_lseek (int file,
|
| 57 |
|
|
int offset,
|
| 58 |
|
|
int whence)
|
| 59 |
|
|
{
|
| 60 |
|
|
if ((STDIN_FILENO == file) ||
|
| 61 |
|
|
(STDOUT_FILENO == file) ||
|
| 62 |
|
|
(STDERR_FILENO == file))
|
| 63 |
|
|
{
|
| 64 |
|
|
return 0;
|
| 65 |
|
|
}
|
| 66 |
|
|
else
|
| 67 |
|
|
{
|
| 68 |
|
|
errno = EBADF;
|
| 69 |
|
|
return (long) -1;
|
| 70 |
|
|
}
|
| 71 |
|
|
} /* _lseek () */
|
