If you get the following error message when compiling device tree blobs, then you will need to update your device tree compiler (dtc) with a specific version designed for dynamic DT loading (e.g enable symbol/fixup support)
dtc: invalid option -- '@'
To clone the official repository for the Device Tree Compiler use:
git clone git://git.kernel.org/pub/scm/utils/dtc/dtc.git
However, this upstream DTC doesn't include the option to enable symbol/fixup support.
To compile a DTC version with symbol/fixup support for dynamic loading of device trees:
git clone https://github.com/pantoniou/dtc.git cd dtc git checkout dt-overlays5 make PREFIX=/usr sudo make install