logo

Linux 内核配置 —— DEVTMPFS


在 Linux 内核配置完成后,建立 ROOTFS 时,/dev 目录下的设备信息可以手动创建,但是也可以通过内核来自动产生。

自动产生 /dev 目录下设备的方法,是在内核配置过程中,加入对 DEVTMPFS 的选择。

> linux-4.10

CONFIG_DEVTMPFS:

 This creates a tmpfs/ramfs filesystem instance early at bootup. 
 In this filesystem, the kernel driver core maintains device 
 nodes with their default names and permissions for all
 registered devices with an assigned major/minor number. 
 Userspace can modify the filesystem content as needed, add
 symlinks, and apply needed permissions. 
 It provides a fully functional /dev directory, where usually
 udev runs on top, managing permissions and adding meaningful
 symlinks. 
 In very limited environments, it may provide a sufficient 
 functional /dev without any further help. It also allows simple 
 rescue systems, and reliably handles dynamic major/minor numbers. 
 
 Notice: if CONFIG_TMPFS isn't enabled, the simpler ramfs
 file system will be used instead. 
 
 Symbol: DEVTMPFS [=y] 
 Type  : boolean 
 Prompt: Maintain a devtmpfs filesystem to mount at /dev 
   Location: 
     -> Device Drivers 
       -> Generic Driver Options 
   Defined at drivers/base/Kconfig:2



欢迎转载,转载请保留:
转自Elta 的博客:http://www.eltaera.com//2017/03/30/linuxdevtmpfs.html

扫描或长按二维码进行打赏:
WechatPayInPost




分类:  linux ,
标签:  linux,config ,
上篇: 使用 tunctl 为 QEMU 创建网桥 下篇: 通过反汇编文件生成函数调用关系图