162306a36Sopenharmony_ci# SPDX-License-Identifier: GPL-2.0-only 262306a36Sopenharmony_ciconfig SYSFS 362306a36Sopenharmony_ci bool "sysfs file system support" if EXPERT 462306a36Sopenharmony_ci default y 562306a36Sopenharmony_ci select KERNFS 662306a36Sopenharmony_ci help 762306a36Sopenharmony_ci The sysfs filesystem is a virtual filesystem that the kernel uses to 862306a36Sopenharmony_ci export internal kernel objects, their attributes, and their 962306a36Sopenharmony_ci relationships to one another. 1062306a36Sopenharmony_ci 1162306a36Sopenharmony_ci Users can use sysfs to ascertain useful information about the running 1262306a36Sopenharmony_ci kernel, such as the devices the kernel has discovered on each bus and 1362306a36Sopenharmony_ci which driver each is bound to. sysfs can also be used to tune devices 1462306a36Sopenharmony_ci and other kernel subsystems. 1562306a36Sopenharmony_ci 1662306a36Sopenharmony_ci Some system agents rely on the information in sysfs to operate. 1762306a36Sopenharmony_ci /sbin/hotplug uses device and object attributes in sysfs to assist in 1862306a36Sopenharmony_ci delegating policy decisions, like persistently naming devices. 1962306a36Sopenharmony_ci 2062306a36Sopenharmony_ci sysfs is currently used by the block subsystem to mount the root 2162306a36Sopenharmony_ci partition. If sysfs is disabled you must specify the boot device on 2262306a36Sopenharmony_ci the kernel boot command line via its major and minor numbers. For 2362306a36Sopenharmony_ci example, "root=03:01" for /dev/hda1. 2462306a36Sopenharmony_ci 2562306a36Sopenharmony_ci Designers of embedded systems may wish to say N here to conserve space. 26