The Kernel - BeagleBone - page 486

Discussion
This recipe uses sysfs , a virtual file system provided by the Linux kernel to talk to hard-
ware. There are many other things to explore in sysfs . Try looking around:
bone# cd /sys
bone# ls
block bus class dev devices firmware fs kernel module power
bone# cd class
bone# ls
arvo graphics lcd power_supply scsi_host usbmon
backlight hidraw leds pps sound vc
bdi hwmon logibone pwm spidev
video4linux
block i2c-adapter mbox pyra spi_master
virtio-ports
bsg i2c-dev mdio_bus rc thermal
vtconsole
dma input mem regulator timed_output watchdog
drm isku misc rtc tty
dvb kone mmc_host savu ubi
firmware koneplus mtd scsi_device udc
gpio kovaplus net scsi_disk uio
It's not hard to guess what's controlled by some of these files.