15f3a211aSAlexey Dobriyanconfig SYSFS 26a108a14SDavid Rientjes bool "sysfs file system support" if EXPERT 35f3a211aSAlexey Dobriyan default y 45f3a211aSAlexey Dobriyan help 55f3a211aSAlexey Dobriyan The sysfs filesystem is a virtual filesystem that the kernel uses to 65f3a211aSAlexey Dobriyan export internal kernel objects, their attributes, and their 75f3a211aSAlexey Dobriyan relationships to one another. 85f3a211aSAlexey Dobriyan 95f3a211aSAlexey Dobriyan Users can use sysfs to ascertain useful information about the running 105f3a211aSAlexey Dobriyan kernel, such as the devices the kernel has discovered on each bus and 115f3a211aSAlexey Dobriyan which driver each is bound to. sysfs can also be used to tune devices 125f3a211aSAlexey Dobriyan and other kernel subsystems. 135f3a211aSAlexey Dobriyan 145f3a211aSAlexey Dobriyan Some system agents rely on the information in sysfs to operate. 155f3a211aSAlexey Dobriyan /sbin/hotplug uses device and object attributes in sysfs to assist in 165f3a211aSAlexey Dobriyan delegating policy decisions, like persistently naming devices. 175f3a211aSAlexey Dobriyan 185f3a211aSAlexey Dobriyan sysfs is currently used by the block subsystem to mount the root 195f3a211aSAlexey Dobriyan partition. If sysfs is disabled you must specify the boot device on 205f3a211aSAlexey Dobriyan the kernel boot command line via its major and minor numbers. For 215f3a211aSAlexey Dobriyan example, "root=03:01" for /dev/hda1. 225f3a211aSAlexey Dobriyan 235f3a211aSAlexey Dobriyan Designers of embedded systems may wish to say N here to conserve space. 24