Bootstrapping Rust and Cargo on FreeBSD/aarch64
At the time of this writing, Rust and Cargo are available on FreeBSD/amd64 and FreeBSD/i386 only, whether it is from rustup or from the FreeBSD ports tree. Here is how I could bootstrap Rust and Cargo for FreeBSD/aarch64 from FreeBSD/amd64.
Base system for the target
To be able to cross-compile anything, you need a userland for the target.