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