Nut/OS  4.10.3
API Reference
read.c
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00001 /*
00002  * Copyright (C) 2001-2003 by egnite Software GmbH. All rights reserved.
00003  *
00004  * Redistribution and use in source and binary forms, with or without
00005  * modification, are permitted provided that the following conditions
00006  * are met:
00007  *
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. Neither the name of the copyright holders nor the names of
00014  *    contributors may be used to endorse or promote products derived
00015  *    from this software without specific prior written permission.
00016  *
00017  * THIS SOFTWARE IS PROVIDED BY EGNITE SOFTWARE GMBH AND CONTRIBUTORS
00018  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00019  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
00020  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL EGNITE
00021  * SOFTWARE GMBH OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
00022  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
00023  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
00024  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
00025  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00026  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
00027  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00028  * SUCH DAMAGE.
00029  *
00030  * For additional information see http://www.ethernut.de/
00031  *
00032  */
00033 
00034 /*
00035  * $Log$
00036  * Revision 1.4  2009/01/17 15:37:52  haraldkipp
00037  * Added some NUTASSERT macros to check function parameters.
00038  *
00039  * Revision 1.3  2009/01/17 11:26:38  haraldkipp
00040  * Getting rid of two remaining BSD types in favor of stdint.
00041  * Replaced 'u_int' by 'unsinged int' and 'uptr_t' by 'uintptr_t'.
00042  *
00043  * Revision 1.2  2004/03/16 16:48:27  haraldkipp
00044  * Added Jan Dubiec's H8/300 port.
00045  *
00046  * Revision 1.1.1.1  2003/05/09 14:40:32  haraldkipp
00047  * Initial using 3.2.1
00048  *
00049  * Revision 1.1  2003/02/04 17:49:08  harald
00050  * *** empty log message ***
00051  *
00052  */
00053 
00054 #include "nut_io.h"
00055 
00056 #include <sys/device.h>
00057 #include <sys/nutdebug.h>
00058 
00063 
00075 int _read(int fd, void *buffer, unsigned int count)
00076 {
00077     NUTFILE *fp = (NUTFILE *) ((uintptr_t) fd);
00078     NUTDEVICE *dev;
00079 
00080     NUTASSERT(fp != NULL);
00081     dev = fp->nf_dev;
00082     if (dev == 0) {
00083         NUTVIRTUALDEVICE *vdv = (NUTVIRTUALDEVICE *) fp;
00084         return (*vdv->vdv_read) (fp, buffer, count);
00085     }
00086     return (*dev->dev_read) (fp, buffer, count);
00087 }
00088