A robust decompiler for this platform must handle the following components:
If you need to "decompile" the physical device (disassembly), you will need specific precision tools for the proprietary screws: Tri-Wing Precision Screwdriver
No essay on decompilation is complete without addressing the legal quagmire. In the United States, the Digital Millennium Copyright Act (DMCA) prohibits circumventing copy protection. However, the Librarian of Congress has granted exemptions for the purpose of "preserving and maintaining" video games that require server-side or obsolete hardware access. Decompilation for interoperability (e.g., to make a game run on a new platform) is legally defensible under fair use in some jurisdictions, following the precedent of Sega v. Accolade (1992).
The decompilation community thrives on collaboration. Join Discord servers associated with projects like pret (the Pokémon Reverse Engineering Team) or specific game decompilations. The pmd-sky project encourages contributors at all skill levels, even suggesting that "if the decomp is too advanced for your skill level, you can still indirectly contribute by submitting research" to their symbol database. nds decompiler
The Nintendo DS (NDS) is a dual-screen ARM-based handheld console released in 2004. Decompilation in the context of NDS games refers to the process of translating compiled machine code (ARM9, ARM7, or Thumb binaries) back into a high-level language, ideally human-readable C or C++ code.
The game code is compiled into machine code for these two distinct instruction set architectures. When a developer compiled a game using tools like the official Nintendo SDK (often based on Green Hills or ARM compilers), the human-readable source code was transformed into raw ARM and Thumb instructions, stripped of variable names, comments, and high-level structure. The NDS decompiler’s job is to reverse this process, recovering as much abstraction as possible from this binary wasteland.
Decompilation is a legal gray area.
An NDS ROM is essentially a file system. Before decompiling code, you must unpack it.
Hex-Rays IDA (Interactive Disassembler) is the industry standard for professional reverse engineering.
This comprehensive guide covers how NDS decompilers work, the primary tools used by the community, and a step-by-step workflow to start reverse engineering your favorite dual-screen classics. The Architecture of a Nintendo DS ROM A robust decompiler for this platform must handle
decompilation projects (found on GitHub). These aim to create a "matching decomp," where the C code, when compiled, produces a byte-for-byte identical ROM to the original. CrystTile2:
The best way to understand NDS reverse engineering is to see it in action. The community has made incredible progress decompiling some of the biggest games on the system. These projects serve as excellent blueprints for learning:
: A command-line utility specifically for extracting 3D models from NDS ROMs. 🏗️ The Decompilation Process Decompilation for interoperability (e