Tips & Tricks

Customizing the device tree on the target

The device tree is a data structure for describing hardware. Rather than hard coding every detail of a device into an operating system, many aspect of the hardware can be described in a data structure that is passed to the operating system at boot time.

For your convenience – all device tree files (dtb) for our designs are included in the SD Card boot partition. Sometimes it’s desired to change certain device tree properties permanently.

For example a custom board has a different reference clock.

https://media.githubusercontent.com/media/analogdevicesinc/documentation/main/docs/linux/kernel/images/dts-dtb.png

  • Mount the FAT32 Boot partition by clicking on the 537MB Volume Icon on the desktop

  • Open a shell by clicking ion the Terminal Icon on the desktop (or CTRL+ALT+t)

  • Now convert the devictree.dtb into a dts file

  • Edit the file (mousepad or vi)

  • Convert the devictree.dts back into its binary format.

  • Unmount the file system (right click)

analog@analog:~$ cd /media/analog/BOOT/
analog@analog:/media/analog/BOOT$ dtc -I dtb devicetree.dtb -O dts -o devicetree.dts
analog@analog:/media/analog/BOOT$ mousepad devicetree.dts &
analog@analog:/media/analog/BOOT$ dtc -I dts devicetree.dts -O dtb -o devicetree.dtb
analog@analog:/media/analog/BOOT$