A "safe" ABI is just a C ABI plus a "safe" Rust crate (the moral equivalent to a C/C++ header file) that wraps it to provide safety guarantees. All bare-metal

A "safe" ABI is just a C ABI plus a "safe" Rust crate (the moral equivalent to a C/C++ header file) that wraps it to provide safety guarantees. All bare-metal "safe" FFI's are ultimately implemented on top of completely "unsafe" assembly, and Rust is not really any different.