/**************************************************************************** * 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 struct file_operations hello_fops ={  0,             /* open */  0,             /* close */  hello_read,    /* read */  0,             /* write */  0,             /* seek */  0              /* ioctl */};/**************************************************************************** * 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 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);}