Maybe it would be easier to translate to Ada? That is for C code that doesn’t make heavy use of malloc/free. The idea of Rust’s borrow checker as I understand it is to statically track the references to malloc’d memory to make sure that you never use-after-free or double-free. If your C code uses malloc in uncontrolled ways, then massaging it to satisfy a borrow checker sounds horribly difficult and you should either give up, or run it under a very managed environment like valgrind. If (as is typical of embedded code) it just does stuff with some fixed memory buffers and doesn’t do much runtime allocation, then there isn’t anything for a borrow checker to look after, so you can use a safe language (Ada) that doesn’t have borrow checking.

Disclaimer: I don’t use Rust at the moment. Someday. I do like Ada despite its verbosity, but it’s not that great at managing dynamic memory. It is starting to take on Rust influences to help with that.