1*4882a593Smuzhiyun# SPDX-License-Identifier: GPL-2.0-only 2*4882a593Smuzhiyunconfig SYSFS 3*4882a593Smuzhiyun bool "sysfs file system support" if EXPERT 4*4882a593Smuzhiyun default y 5*4882a593Smuzhiyun select KERNFS 6*4882a593Smuzhiyun help 7*4882a593Smuzhiyun The sysfs filesystem is a virtual filesystem that the kernel uses to 8*4882a593Smuzhiyun export internal kernel objects, their attributes, and their 9*4882a593Smuzhiyun relationships to one another. 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun Users can use sysfs to ascertain useful information about the running 12*4882a593Smuzhiyun kernel, such as the devices the kernel has discovered on each bus and 13*4882a593Smuzhiyun which driver each is bound to. sysfs can also be used to tune devices 14*4882a593Smuzhiyun and other kernel subsystems. 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun Some system agents rely on the information in sysfs to operate. 17*4882a593Smuzhiyun /sbin/hotplug uses device and object attributes in sysfs to assist in 18*4882a593Smuzhiyun delegating policy decisions, like persistently naming devices. 19*4882a593Smuzhiyun 20*4882a593Smuzhiyun sysfs is currently used by the block subsystem to mount the root 21*4882a593Smuzhiyun partition. If sysfs is disabled you must specify the boot device on 22*4882a593Smuzhiyun the kernel boot command line via its major and minor numbers. For 23*4882a593Smuzhiyun example, "root=03:01" for /dev/hda1. 24*4882a593Smuzhiyun 25*4882a593Smuzhiyun Designers of embedded systems may wish to say N here to conserve space. 26