EBC Exercise 11a Device Trees

The Device Tree (DT), and Device Tree Overlay are a way to describe hardware in a system. This introduction is heavily based on Adafruit's Introduction to the BeagleBone Black Device Tree using Derek Molloy's gpio example.

Compile
beagle$ dtc -O dtb -o DM-GPIO-Test-00A0.dtbo -b 0 -@ DM-GPIO-Test.dts Compiling the overlay from .dts to .dtbo

Install
beagle$ cp DM-GPIO-Test-00A0.dtbo /lib/firmware beagle$ echo DM-GPIO-Test > $SLOTS

Verify
Check to be sure it worked beagle$ cat $SLOTS 0: 54:PF--- 1: 55:PF--- 2: 56:PF--- 3: 57:PF--- 4: ff:P-O-L Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G 5: ff:P-O-L Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI 7: ff:P-O-L Override Board Name,00A0,Override Manuf,DM-GPIO-Test It's appeard in slot 7. You can remove it with beagle$ echo -7 > $SLOTS Be careful though, the current versions appear unstable when removing this way.