Start with a small goal—a single function, a piece of text, a simple mechanic. Use the tools described above: unpack the ROM, load the binary into Ghidra, set breakpoints in No$GBA, and start exploring. Join the community on Discord or forums like GBAtemp. Share your findings, however modest. Every labeled function and documented subroutine brings the community closer to understanding these remarkable games.
It is important to distinguish between these two vital tools:
It has excellent support for ARM architectures, which is what the NDS uses. Its decompiler is top-notch, producing readable pseudo-C. nds decompiler
Its Medium-Level Intermediate Language (MLIL) provides a incredibly readable abstraction of assembly code, bridging the gap between a pure disassembly and a full C decompilation. 4. Specialized NDS Rom Tools
Choose the correct processor: (This matches the ARM9 processor in the DS). 3. Identifying the Binary Start with a small goal—a single function, a
Unlike a disassembler, which merely turns binary into assembly code, a decompiler attempts to recreate high-level C or C++ source code, making the logic significantly easier to read and modify. Top NDS Decompiler Tools and Frameworks
Highly scriptable with Python and more affordable than IDA Pro. The Step-by-Step NDS Decompilation Workflow Share your findings, however modest
The community has developed specific plugins (like NDS loaders) that automatically parse NDS ROM headers, split ARM9/ARM7 binaries, and map the correct memory regions upon import. 2. IDA Pro (Interactive Disassembler)
Once unpacked, you need tools to make sense of the ARM7 and ARM9 binaries.
Reverse engineering and decompilation exist in a nuanced legal space. Generally, decompiling code you own for personal use, educational purposes, interoperability, or archival preservation is protected under various fair use doctrines. However, distributing copyrighted game binaries, proprietary SDK code, or assets (like graphics and music) is illegal.
Reversing an NDS game requires a structured workflow to transform raw ROM data into structured, legible code. Step 1: ROM Unpacking