Pokémon Black 2 and White 2

A work-in-progress decompilation of Pokémon Black 2 and White 2, with a long-term goal of a native PC port. Both USA/Europe ROMs rebuild byte for byte from the same source tree.

Progress

Progress updates automatically from CI. ByteMatch shows it for each version, for ARM9 main and the overlays, and for the game's code and each library.

Build

Requires Linux, WSL or macOS, Python 3.11+, ninja, and LLVM (clang and llvm-objcopy on your PATH).

1. Place your own ROM dumps in orig/, using the filenames below.

2. Configure and build:

   python3 configure.py
   ninja
   

The first run downloads the remaining tools. Every available version is built and checked against its SHA1. ROMs are not included or provided.

ROM (USA/Europe, NDSi Enhanced)	Input file	SHA1
Black 2	orig/baserom_b2_us.nds	e51e6dfb8678a3d19dcd2a10691b96a569ca0abb
White 2	orig/baserom_w2_us.nds	b5d7490be7b415b8f1e672a53e978a9cc667e56a

Output: build/pokeblack2_us.nds and/or build/pokewhite2_us.nds. See Build details for macOS setup, toolchain options and modified builds.

Contribute

Read CONTRIBUTING.md for the workflow and rules. Claim an overlay's issue before starting work. CI compiles every C file for both versions; fork PRs must verify ROM matching locally.

Documentation

Guide	Covers
Build details	Setup and build options
Decompiling	Workflow and tools
Matching	MWCC behavior and matching techniques
Code organization	Source layout, libraries and names
Native port notes	Recovered platform assumptions and open porting questions
Source files	Overlay files and boundary evidence
Nonmatching functions	Remaining mismatches
Game data	Data formats and archives
Scripts	Trainer AI, battle animation and field scripts
Configs and ROMs	dsd configuration and ROM structure
Tools	Tool reference

License

GNU GPL v3.0, including the symbol names imported from swan.