This crate is intended for working with the GBA.
To build for the GBA you'll need to use build-std
and you'll also need to
activate the compiler-builtins-weak-intrinsics
feature.
The following should be somewhere in your .cargo/config.toml
:
[unstable]
build-std = ["core"]
build-std-features = ["compiler-builtins-weak-intrinsics"]