[xobs]

The Rust runtime will, at a minimum, set up the stack pointer, zero out the .bss, and fill in the .data section. You're right in that a heap is optional, but Rust will get very cranky if you don't set up the .data or .bss sections.

[comex]

As will C.

[oguz-ismail2]

No idea what either of you are talking about. It's the operating system that sets those things up not the language runtime.