如何从Linux内核模块的init_module代码创建设备节点? [英] How to create a device node from the init_module code of a Linux kernel module?

问题描述

我正在为linux内核编写一个模块，我想在init函数中创建一些设备节点

I am writing a module for the linux kernel and I want to create some device nodes in the init function

int init_module(void)
{
    Major = register_chrdev(0, DEVICE_NAME, &fops);
 // Now I want to create device nodes with the returned major number
}

我还希望内核为我的第一个节点分配一个次要编号，然后由我自己分配其他节点的次要编号.

I also want the kernel to assign a minor number for my first node, and then I will assign the other nodes' minor numbers by myself.

如何在代码中执行此操作.我不想使用mknod从外壳创建设备

How can I do this in the code. I dont want to create devices from the shell using mknod

推荐答案

要对设备编号和设备创建有更多控制，您可以执行以下步骤(而不是register_chrdev()):

To have more control over the device numbers and the device creation you could do the following steps (instead of register_chrdev()):

1. 致电alloc_chrdev_region()获取一个主要号码和一系列次要号码.
2. 使用class_create()为您的设备创建设备类.
3. 对于每个设备，调用cdev_init()和cdev_add()将字符设备添加到系统中.
4. 对于每个设备，呼叫device_create().结果，除其他外， Udev 将为您的设备创建设备节点.不需要mknod等. device_create()还允许您控制设备的名称.

1. Call alloc_chrdev_region() to get a major number and a range of minor numbers to work with.
2. Create device class for your devices with class_create().
3. For each device, call cdev_init() and cdev_add() to add the character device to the system.
4. For each device, call device_create(). As a result, among other things, Udev will create device nodes for your devices. No need for mknod or the like. device_create() also allows you to control the names of the devices.

网上可能有很多这样的例子，其中一个在这里.

There are probably many examples of this on the Net, one of them is here.

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