Managing the device tree data in U-Boot
				 =======================================

The 'fdt' command can be used to manipulate the device tree (DT) data
that is passed from U-Boot to Linux.

- 'fdt boardsetup' will trim out some device nodes according to
  environment settings:

Environment setting		removed nodes
---------------------------------------------
otg_mode=host			usbh1
otg_mode=device			usbotg
otg_mode=<UNSET>		<both of the above> + usbphy

touchpanel=edt-ft5x06		ti,tsc2007
touchpanel=tsc2007		edt,edt-ft5x06
touchpanel=<UNSET>		<both of the above>

Note: This command is automatically executed when booting Linux via
      'run bootm_cmd'.

- 'fdt rm' and 'fdt add' can be used to remove/create additional nodes.

The whole DT data can be saved to and reloaded from the flash partition
'dtb' (or any other partition):
  nand erase.part dtb
  nand write.jffs2 ${fdtaddr} dtb ${fdtsize}

If a DT is loaded from flash which should not be further manipulated
upon booting Linux, the string 'fdt boardsetup;' should be removed
from the 'bootm_cmd' environment variable.

Loading the DT data:
  nand read ${fdtaddr} dtb