Linux内核模块编程指南2.6版

需积分: 9 107 浏览量更新于2024-07-21 1 收藏 539KB PDF 举报

"《Linux内核模块编程指南》是一本英文版的开源书籍，由Peter Jay Salzman、Michael Burian和Ori Pomerantz合著，适用于Linux内核2.6版本。该书旨在引导读者进行Linux内核模块的开发工作，遵循Open Software License 1.1版本的条款分发，旨在无任何保修的情况下提供有用的信息，允许个人或商业用途的自由复制和修改，但需保留原有的版权信息。" 在《Linux内核模块编程指南》中，作者深入浅出地介绍了如何编写和理解Linux内核模块，这对于任何想要深入了解操作系统内部机制或者希望为Linux内核贡献代码的人来说，都是宝贵的资源。以下是该书可能涵盖的一些关键知识点： 1. **内核模块基础**：介绍内核模块的基本概念，包括为什么需要内核模块，以及它们在系统中的角色。讲解模块的加载和卸载机制，如`insmod`, `rmmod`和`modprobe`等命令的使用。 2. **模块编译与构建**：详细阐述如何配置内核以支持模块编译，使用Makefile编写规则，以及如何处理模块与其他内核源码的依赖关系。 3. **内核API**：涵盖内核提供的函数库，如内存管理（kmalloc, kfree）、进程管理（task_struct, wake_up_process）、中断处理、定时器（timer_list）等，以及如何在模块中使用这些API。 4. **设备驱动编程**：讲解如何编写简单的字符设备驱动和块设备驱动，涉及中断处理、DMA、I/O端口访问、设备注册和注销等。 5. **文件系统接口**：介绍如何创建新的文件系统，包括VFS（虚拟文件系统）的概念，以及如何实现文件操作函数，如open, read, write, ioctl等。 6. **内核同步与并发控制**：讲解信号量、自旋锁、读写锁、原子操作和完成变量等内核同步原语的使用，防止数据竞争和死锁。 7. **系统调用与内核空间通信**：如何添加新的系统调用，以及通过sysfs、procfs或netlink等方式在用户空间与内核空间之间传递信息。 8. **调试技术**：介绍gdb的内核调试功能，kdump用于崩溃转储分析，以及sysfs和debugfs在模块调试中的应用。 9. **模块版本管理**：解释如何处理模块与不同内核版本的兼容性问题，以及如何使用`module_init`和`module_exit`宏来初始化和清理模块。 10. **内核模块的生命周期**：讨论模块的加载、运行、卸载过程中的注意事项，以及如何处理错误和异常情况。这本书不仅适合初学者，也适合有一定经验的开发者作为参考。通过学习，读者将能够独立编写和维护自己的Linux内核模块，进一步提升对Linux内核的理解和掌控能力。

printk(KERN_INFO "Hello, world 4\n");

return 0;

}

static void __exit cleanup_hello_4(void)

{

printk(KERN_INFO "Goodbye, world 4\n");

}

module_init(init_hello_4);

module_exit(cleanup_hello_4);

* You can use strings, like this:

* Get rid of taint message by declaring code as GPL.

MODULE_LICENSE("GPL");

* Or with defines, like this:

MODULE_AUTHOR(DRIVER_AUTHOR); /* Who wrote this module? */

MODULE_DESCRIPTION(DRIVER_DESC); /* What does this module do */

* This module uses /dev/testdevice. The MODULE_SUPPORTED_DEVICE macro might

* be used in the future to help automatic configuration of modules, but is

* currently unused other than for documentation purposes.

MODULE_SUPPORTED_DEVICE("testdevice");

2.6. Passing Command Line Arguments to a Module

Modules can take command line arguments, but not with the argc/argv you might be used to.

To allow arguments to be passed to your module, declare the variables that will take the values of the

command line arguments as global and then use the module_param() macro, (defined in

linux/moduleparam.h) to set the mechanism up. At runtime, insmod will fill the variables with any

command line arguments that are given, like ./insmod mymodule.ko myvariable=5. The variable

declarations and macros should be placed at the beginning of the module for clarity. The example code should

clear up my admittedly lousy explanation.

The module_param() macro takes 3 arguments: the name of the variable, its type and permissions for the

corresponding file in sysfs. Integer types can be signed as usual or unsigned. If you'd like to use arrays of

integers or strings see module_param_array() and module_param_string().

int myint = 3;

module_param(myint, int, 0);

Arrays are supported too, but things are a bit different now than they were in the 2.4. days. To keep track of

the number of parameters you need to pass a pointer to a count variable as third parameter. At your option,

you could also ignore the count and pass NULL instead. We show both possibilities here:

The Linux Kernel Module Programming Guide

Chapter 2. Hello World 11

int myintarray[2];

module_param_array(myintarray, int, NULL, 0); /* not interested in count */

int myshortarray[4];

int count;

module_parm_array(myshortarray, short, , 0); /* put count into "count" variable */

A good use for this is to have the module variable's default values set, like an port or IO address. If the

variables contain the default values, then perform autodetection (explained elsewhere). Otherwise, keep the

current value. This will be made clear later on.

Lastly, there's a macro function, MODULE_PARM_DESC(), that is used to document arguments that the

module can take. It takes two parameters: a variable name and a free form string describing that variable.

Example 2−7. hello−5.c

* hello−5.c − Demonstrates command line argument passing to a module.

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/stat.h>

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Peter Jay Salzman");

static short int myshort = 1;

static int myint = 420;

static long int mylong = 9999;

static char *mystring = "blah";

static int myintArray[2] = { −1, −1 };

static int arr_argc = 0;

* module_param(foo, int, 0000)

* The first param is the parameters name

* The second param is it's data type

* The final argument is the permissions bits,

* for exposing parameters in sysfs (if non−zero) at a later stage.

module_param(myshort, short, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);

MODULE_PARM_DESC(myshort, "A short integer");

module_param(myint, int, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);

MODULE_PARM_DESC(myint, "An integer");

module_param(mylong, long, S_IRUSR);

MODULE_PARM_DESC(mylong, "A long integer");

module_param(mystring, charp, 0000);

MODULE_PARM_DESC(mystring, "A character string");

* module_param_array(name, type, num, perm);

* The first param is the parameter's (in this case the array's) name

* The second param is the data type of the elements of the array

* The third argument is a pointer to the variable that will store the number

* of elements of the array initialized by the user at module loading time

* The fourth argument is the permission bits

The Linux Kernel Module Programming Guide

Chapter 2. Hello World 12

剩余81页未读，继续阅读

qq1223386926

粉丝: 9

Linux内核模块编程指南2.6版

The Linux Kernel Module Programming Guide 2.6 中英文對照版

The Linux Kernel Module Programming Guide

The Linux Kernel Module Programming Guide 2.6 中文版+英文版

linux平台iic设备驱动

linux驱动开发学习路线

linux buildroot eval kernel-module用法

如何去学习Linux kernel

我有一个 arm 开发板，我想在上面调试 linux kernel，请问如何实现

Linux kernel学习路线

#include <linux/module.h>

最新资源