Please be careful with random device trees.
They could contain wrong power management settings which could destroy your board.
The device tree bellow is out-dated. Visit grate-driver/linux for a more recent device tree. The device tree from there changes aliases of the mmc's, so your existing scripts will not be compatible.
A device tree is a standardized way on ARM to tell the kernel which hardware is present and how it is connected.
The current devicetree can be found here:
Screen (touch, lvds encoder, backlight)
SD Card (+UHS-I mode)
1GB DDR3 RAM (2GB should be possible)
HDMI (with audio)
Vol+/-, PWR, Windows Buttons
NCT1008 CPU and case Temperature sensor
Lid (close tCover to suspend the device)