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by sciencejerk 34 days ago
I recently heard that Super Mario 64 (N64) modding community reverse engineered the game enough to recreate more-or-less accurate C code that can be compiled in binaries to execute on many popular target architectures. Have you managed to get beloved games into modifiable C code? Or is it more common to invest a lot of work to document assembly language functions? I know some old assembly but no idea what is involved at a high level. Maybe you explain in your lessons?

Also, how to folks obtain binaries? Presumably unless there is a source code breach or vulnerability, source never gets exposed, is thst correct?
2 comments
xahrepap 34 days ago
Mario 64 was byte for byte decompiled to C. It was helped by using the Debug symbols accidentally(?) compiled into the final version of the game.

Otherwise they reference rips of the original game.

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Randomno 34 days ago
> It was helped by using the Debug symbols accidentally(?) compiled into the final version of the game.

Don't think this was the case, what helped was it being compiled without optimizations.

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jackpriceburns 34 days ago
Most games will have been written in a higher level language first (like C or C++) and then compiled into assembly. With matching decomp, we write C, compile it to assembly, and see how much it matches the retail assembly. Using this we can write C that we theorise is almost identical to how it would have been written originally. There are things lost during the compilation process (like comments, function names, etc) these we have to name manually and it's a long process to do! But yes, the goal is to have C at the end and once you have C you can recompile using a different compiler and target any architecture you like
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sciencejerk 33 days ago
Thanks for replying! Going to check out your educational resources
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teaearlgraycold 34 days ago
I suspect LLMs would do a good first pass with function naming.
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jackpriceburns 34 days ago
They do an alright job, but they deffo need human-in-the-loop for the best results. I wrote on my blog about how I wrote an MCP to communicate with the Dolphin emulator. Allows Claude Code to set breakpoints, read the memory, write the memory, etc. It was a super fun way to work with Claude and has made naming functions/structs/fields/etc much easier! https://jpb.dev/blog/dolphin-debugger-mcp/
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