109 lines
3.9 KiB
C
109 lines
3.9 KiB
C
/****************************************************************************
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* examples/pashello/device.c
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*
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* Copyright (C) 2008, 2012 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Compilation Switches
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/types.h>
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#include <string.h>
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#include <errno.h>
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#include <nuttx/fs/fs.h>
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#include "hello.h"
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#include "pashello.h"
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/****************************************************************************
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* Private Function Prototypes
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****************************************************************************/
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static ssize_t hello_read(struct file *, char *, size_t);
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/****************************************************************************
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* Private Data
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****************************************************************************/
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static const struct file_operations hello_fops =
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{
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NULL, /* open */
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NULL, /* close */
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hello_read, /* read */
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NULL, /* write */
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NULL, /* seek */
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NULL, /* ioctl */
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NULL /* poll */
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};
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/****************************************************************************
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* Private Functions
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****************************************************************************/
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static ssize_t hello_read(struct file *filep, char *buffer, size_t len)
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{
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off_t offset = filep->f_pos; /* Start read position */
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ssize_t nread = 0; /* Bytes read -- assume EOF */
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/* Make sure that the offset is within the .pex file */
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if (offset < hello_pex_len)
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{
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/* Make sure the read does not extend beyond the .pex file */
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nread = len;
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if (nread + offset > hello_pex_len)
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{
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nread = hello_pex_len - offset;
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}
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memcpy(buffer, &hello_pex[offset], nread);
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filep->f_pos += nread;
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}
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return nread;
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}
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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void hello_register(void)
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{
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(void)register_driver("/dev/hello", &hello_fops, 0444, NULL);
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}
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