See this article I used for reference.
# Add Rust target
rustup target add armv7-unknown-linux-musleabihf
# Install linker
brew install arm-linux-gnueabihf-binutils
# Configure Cargo with the following:
# [target.armv7-unknown-linux-musleabihf]
# linker = "arm-linux-gnueabihf-ld"
echo "[target.armv7-unknown-linux-musleabihf]\nlinker = \"arm-linux-gnueabihf-ld\"" >> ~/.cargo/config