This might actually be a solved problem soonish, LLMs are unreasonably effective at writing compilers and C is designed to be easy to write a compiler for, which also helps. I don’t know if anyone tried, but there’s been related work posted here on HN recently: a revived Java compiler and the N64 decompilation project. Mashed together you can almost expect to be able to generate C compilers for obscure architectures on demand given just some docs and binary firmware dumps.