mirror of
https://github.com/apache/nuttx-apps.git
synced 2025-07-05 03:13:47 +08:00
27846ffec7
Renaming "modlib" to "libelf" is more in line with the implementation content, which makes it easier for individual developers to understand the capabilities of this module. CONFIG_LIBC_MODLIB -> CONFIG_LIBC_ELF Signed-off-by: chao an <anchao.archer@bytedance.com>
131 lines
4.6 KiB
C
131 lines
4.6 KiB
C
/****************************************************************************
|
|
* apps/examples/module/chardev/chardev.c
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/types.h>
|
|
#include <stdbool.h>
|
|
#include <string.h>
|
|
#include <errno.h>
|
|
#include <syslog.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/module.h>
|
|
#include <nuttx/lib/elf.h>
|
|
#include <nuttx/fs/fs.h>
|
|
|
|
/****************************************************************************
|
|
* Private data
|
|
****************************************************************************/
|
|
|
|
static const char g_read_string[] = "Hi there, apps/examples/module test\n";
|
|
|
|
/****************************************************************************
|
|
* Private Function Prototypes
|
|
****************************************************************************/
|
|
|
|
static ssize_t chardev_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t buflen);
|
|
static ssize_t chardev_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t buflen);
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
static const struct file_operations g_chardev_fops =
|
|
{
|
|
NULL, /* open */
|
|
NULL, /* close */
|
|
chardev_read, /* read */
|
|
chardev_write, /* write */
|
|
};
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: chardev_read
|
|
****************************************************************************/
|
|
|
|
static ssize_t chardev_read(FAR struct file *filep, FAR char *buffer,
|
|
size_t len)
|
|
{
|
|
size_t rdlen = strlen(g_read_string);
|
|
ssize_t ret = MIN(len, rdlen);
|
|
|
|
memcpy(buffer, g_read_string, ret);
|
|
|
|
syslog(LOG_INFO, "chardev_read: Returning %d bytes\n", (int)ret);
|
|
lib_dumpbuffer("chardev_read: Returning",
|
|
(FAR const uint8_t *)buffer, ret);
|
|
return ret;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: chardev_write
|
|
****************************************************************************/
|
|
|
|
static ssize_t chardev_write(FAR struct file *filep, FAR const char *buffer,
|
|
size_t len)
|
|
{
|
|
syslog(LOG_INFO, "chardev_write: Writing %d bytes\n", (int)len);
|
|
lib_dumpbuffer("chardev_write: Writing", (FAR const uint8_t *)buffer, len);
|
|
return len;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Name: module_uninitialize
|
|
****************************************************************************/
|
|
|
|
destructor_function void module_uninitialize(void)
|
|
{
|
|
/* TODO: Check if there are any open references to the driver */
|
|
|
|
syslog(LOG_INFO, "module_uninitialize\n");
|
|
unregister_driver("/dev/chardev");
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: module_initialize
|
|
*
|
|
* Description:
|
|
* Register /dev/chardev
|
|
*
|
|
****************************************************************************/
|
|
|
|
constructor_fuction void module_initialize(void)
|
|
{
|
|
syslog(LOG_INFO, "module_initialize\n");
|
|
register_driver("/dev/chardev", &g_chardev_fops, 0666, NULL);
|
|
}
|