I don't want to be too contrary, but, building the DMD wallet on the RPi can take forever and fail multiple times before succeeding (if ever).
I recommend using the depends toolkit and building the ARM/RASPi wallet on Debian 9 (VM or install).
Then, you just need a Raspberry Pi with Raspbian installed, and you can copy the wallet with no dependencies.
https://www.raspberrypi.org/downloads/raspbian/Here are some tips:
Install Debian 9 in a virtual machine or download on from OSboxes.org -
http://www.osboxes.org/debian/Install the build environment dependencies for the Raspberry Pi -
sudo apt install build-essential libtool autotools-dev autoconf pkg-config curl gcc-aarch64-linux-gnu g++-aarch64-linux-gnu
build the dependencies for the DMD wallet without the GUI (cli only) building for QT needs work -
cd depends && make HOST=aarch64-linux-gnu NO_QT=1
Change back to the DMD root directory
Prepare the configure script -
Configure for the build No GUI, cli only-
./configure --prefix=$(pwd)/depends/aarch64-linux-gnu
Build it -
Strip the debug symbols -
aarch64-linux-gnu-strip src/diamondd src/diamond-cli src/diamond-tx
Grab those three files (src/diamondd src/diamond-cli src/diamond-tx),
and copy them to your raspberry pi via the SD card or scp/sftp.
Startup scripts for the Raspberry Pi are more complicated using either System V or Systemd.
This is loosely documented in various Pi forums, PM me if you need further assistance with this.
All of this is documented here -
https://github.com/LIMXTEC/DMDv3/tree/master/dependsHere are some pre-built binaries to try:
https://drive.google.com/file/d/1NfjOYoIEZugazqFrZCQaruTJEkAqTzE7/view?usp=sharing