device number(dev_t)

最新推荐文章于 2024-10-14 15:04:50 发布

转载最新推荐文章于 2024-10-14 15:04:50 发布 · 949 阅读

Linux 专栏收录该内容

29 篇文章

订阅专栏

本文详细解释了dev_t类型在设备管理中的应用，包括其构造、方法及注册与释放设备号的机制。

device number(dev_t)

dev_t

description:
the dev_t type in is used to hold device numbers—both the major and minor

parts.

header:
#include

constructor:
MKDEV(int major, int minor);

method:
    MAJOR(dev_t dev);    //obtain the major part of a dev_t
    MINOR(dev_t dev);    //obtain the minor part of a dev_t
    register_chrdev_region();    //manually obtain(register) device numbers

from the system
alloc_chrdev_region(); //allocate a major number by kernel
unregister_chrdev_region(); //free the device number back to kernel

int print_dev_t(char *buffer, dev_t dev); //encode the device number into the given buffer; 
char *format_dev_t(char *buffer, dev_t dev); //encode the device number into the given buffer;