Ghidra requires you to create a custom memory map for the NDS. Without it, the decompiler will produce nonsense like:
Decompiling a Nintendo DS (NDS) game is a multi-step process that has become significantly more accessible with modern tools. Unlike simple "one-click" decompilers for high-level languages, NDS decompilation involves unpacking the ROM, decrypting its contents, and then using a reverse engineering suite to turn binary code back into readable C or assembly. 1. Essential Tools for Your Toolkit
: Automatically generate linker scripts with the correct link order to ensure the code can be recompiled into an exact binary match. Code Delinking
Modern reverse engineering rarely relies on a single standalone "NDS Decompiler" application. Instead, developers use powerful, generalized interactive disassemblers and decompilers equipped with NDS-specific scripts and loaders. nds decompiler
: A command-line utility specifically for extracting 3D models from NDS ROMs. 🏗️ The Decompilation Process
The Nintendo DS frequently switches between ARM mode (for performance-heavy tasks) and Thumb mode (to save RAM). Decompilers sometimes misinterpret where this switch happens, resulting in completely broken, garbled pseudocode until manually corrected by the user.
Early NDS games heavily relied on Nintendo’s official software development kits (SDKs). By applying known function signatures (using tools like SidebySide or signature databases), you can instantly identify standard library functions like OS_Printf or MI_CpuCopy . This eliminates a massive amount of guesswork. Applications: Why Decompile NDS Games? Ghidra requires you to create a custom memory
has been the standard for DS debugging for years. Despite its quirky interface, its debugger is widely considered the most powerful available, with breakpoints, CPU data views, tile viewers, and advanced features. The debug version recently became freeware, removing the previous paywall. Many hackers pair No$GBA with CrystalTile2 to support more advanced formats and share debugging information via the NEF format.
The Homebrew scene is the ethical safe harbor: decompile your own NDS programs to study compilation, or decompile open-source DS demos.
: Include logic to identify and name ARM9 sections based on their start addresses, reducing manual reverse-engineering time. Automation & Efficiency Zero-Input Setup the ARM7 binary
Before feeding code into a decompiler, you need to extract the binaries from the .nds container file. Tools like or Tinke are essential for unpacking the ROM into its constituent parts: the ARM9 binary, the ARM7 binary, the file allocation table (FAT), and the file name table (FNT). The NDS Decompilation Workflow
Do you have a in mind that you want to analyze?
Notable successes include the complete decompilation of Pokémon Diamond and Pearl (pokediamond project) and Super Mario 64 DS . These projects provide a fully recompilable C source tree that matches the original game byte-for-byte. The Step-by-Step NDS Decompilation Process