How to convert an ELF executable to C code? The generated C code need not be human-readable

Question

I have an ELF file that I would like to decompile into C code, and make simple changes to the resulting C code and rebuild it into an ELF.

Answer 1

This will give you (almost) an assembly code translation:

objdump --disassemble <elf file>

I say almost because the output contains some annotations like binary file position markers and can't serve directly as input to an assembler, but it's close.

Answer 2

You write a simulator for the processor, then you run the elf instructions through your simulated processor. It's generally not too much of a task because even CISC processors have relatively small, contained instruction sets that perform simple operations.

When you've got that working, look at more efficient solutions, like outputting C code to match instructions.