@mohamedkallel To confirm, when you say SDK, do you mean the build system? Meaning https://github.com/OnionIoT/source and/or https://github.com/openwrt/openwrt? This is an important distinction because there is an OpenWRT SDK that's used for just building packages. If you do mean build system, I believe you have to rebuild the kernel for the DTS changes to take effect. I can't 100% recall but I believe there's a tmp directory that needs to be deleted before recompiling. EDIT: just saw this in your post: @mohamedkallel said in Change the Device Tree Source in OpenWRT 22.03 for Omega2: copied these 2 files from Openwrt SDK 18 from onion git repo (source): https://github.com/OnionIoT/source.git I put these 2 files (OMEGA2.dst and OMEGA2.dtsi) under the directory "target/linux/ramips/dts/" in the new openwrt SDK 22.03 The DTS files have changed quite a bit from OpenWRT 18.06 to OpenWRT 22.03 - so they can't just be copied over from 18 to 22. You will need to modify the existing DTS files in OpenWRT 22.03 by hand.