Embedded Linux Development Using Yocto Project Cookbook - Second Edition

Looking at the device tree from U-Boot

The U-Boot bootloader offers the fdt command to interact with a device tree blob. In the Wandboard's default environment, there are two variables related to the device tree:

• fdtfile: This variable contains the name of the device tree file used
• fdt_addr: This variable contains the location in memory to load the device tree

To fetch the Wandboard's device tree from the TFTP server location and place it in memory, we use the following command:

> tftp ${fdt_addr} ${fdtfile}  

Once we have the device tree blob in memory, we tell U-Boot where it is located:

> fdt addr ${fdt_addr}  

And then we can inspect nodes from the device tree using the full path to them from the root node. To inspect the selected levels, ...