Name: devfs Version: 99.21 Kernelver: 2.2.20 Status: 9 Author: Richard Gooch Description: Device File System Date: 4-DEC-2001 Descfile-URL: ftp://ftp.atnf.csiro.au/pub/people/rgooch/linux/kernel-patches/v2.2/devfs.desc Download-URL: ftp://ftp.atnf.csiro.au/pub/people/rgooch/linux/kernel-patches/v2.2/devfs-patch-current.gz Homepage-URL: http://www.atnf.csiro.au/~rgooch/linux/kernel-patches.html Manual-URL: http://www.atnf.csiro.au/~rgooch/linux/docs/devfs.html Devfs is an alternative to "real" character and block special devices on your root filesystem. Kernel device drivers can register devices by name rather than major and minor numbers. These devices will appear in the devfs automatically, with whatever default ownership and protection the driver specified. NOTE that devfs is entirely optional. If you prefer the old disc-based device nodes, then simply leave CONFIG_DEVFS_FS=n (the default). In this case, nothing will change. There are two aspects to devfs: one is the underlying device namespace, which is a namespace just like any mounted filesystem. The other aspect is the filesystem code which provides a view of the device namespace. The reason I make a distinction is because the devfs can be mounted many times, with each mount showing the same device namespace. Changes made are global to all mounted devfs filesystems. Also, because the devfs namespace exists without any devfs mounts, you can easily mount the root filesystem by referring to an entry in the devfs namespace.