register_chrdev() register_chrdev_region() alloc_chrdev_region的区别?
在fs.h中的申明如下:分配设备号:externintalloc_chrdev_region(dev_t*,unsigned,unsigned,constchar*);externintregister_chrdev_region(dev_t,unsigned,constchar*);注册设备:externintregister_chrdev(unsignedint,constchar*,