While this is true for many embedded platforms, if it's an architecture that LLVM knows about, you can use Rust on it. That said, many have just a proprietary C compiler, or something similar for a barrier to entry, it's true.

That's why I'm looking at Nim http://nim-lang.org/ - it generates C code and compiles through GCC

I wonder how Haskell DSL (I think one is called Atom) would fare on this.