|  | # SPDX-License-Identifier: GPL-2.0-only | 
|  | config SYSFS | 
|  | bool "sysfs file system support" if EXPERT | 
|  | default y | 
|  | select KERNFS | 
|  | help | 
|  | The sysfs filesystem is a virtual filesystem that the kernel uses to | 
|  | export internal kernel objects, their attributes, and their | 
|  | relationships to one another. | 
|  |  | 
|  | Users can use sysfs to ascertain useful information about the running | 
|  | kernel, such as the devices the kernel has discovered on each bus and | 
|  | which driver each is bound to. sysfs can also be used to tune devices | 
|  | and other kernel subsystems. | 
|  |  | 
|  | Some system agents rely on the information in sysfs to operate. | 
|  | /sbin/hotplug uses device and object attributes in sysfs to assist in | 
|  | delegating policy decisions, like persistently naming devices. | 
|  |  | 
|  | sysfs is currently used by the block subsystem to mount the root | 
|  | partition.  If sysfs is disabled you must specify the boot device on | 
|  | the kernel boot command line via its major and minor numbers.  For | 
|  | example, "root=03:01" for /dev/hda1. | 
|  |  | 
|  | Designers of embedded systems may wish to say N here to conserve space. |