Build u_boot fail for dtc version too old

i build u_boot source cold on my host pc , finally warning is in the picture. please help how to resolve . thanksdtc

Upgrade the dtc on your host?

i just follow the steps refered in the website. and i want to know what 's the problem.

If you type “dtc --version” on your host, what will be show?

now i used command “sudo apt-get install device-tree-compiler” to install .“dtc --version” is DTC 14.5, then i make,i worked,but many warnings , i don’nt know whether it is something wrong.

It should be fine.

As @WayneWWW said, it should not matter. However, realize that the kernel source for every single kernel release also comes with dtc. There is a target, “make dtc” I think, which should build a version from that kernel source.