DKB Recomp

DKB Recomp is a static recompilation of Donkey Kong Bananza (Nintendo Switch 2, 2025) into a native Windows x86-64 application with a Vulkan renderer. There is no emulator at run time: the game's ARM64 code is translated to C ahead of time and compiled into one executable, and its graphics calls are answered by a host implementation of NVN 2. It is built on TotK Recomp, which does the same for Tears of the Kingdom on the original Switch.

As far as we know, no other static recompilation of a Switch 2 game is public.

[!IMPORTANT] No game files are included, and none ever will be. You need your own copy of Donkey Kong Bananza, dumped from your own console. Instructions for obtaining those files will not be provided. The game itself is never downloadable: the release carries the installer, and everyone builds the game from their own dump.

Status

Not playable yet. The game boots, goes through the title screen into the tutorial cave, renders the 3D scene and answers the controller: you can walk and punch through the mining tunnel, with the guide movies playing, and one hand-played run reached the Ingot Isle Cave-In section. It still can crash (on NVIDIA two light quads are skipped to avoid a GPU fault, #9), and many effects are missing. The latest release carries an installer that builds the game from your own dump: docs/installer.md. Progress, day by day: docs/devlog.md.

Phase		State
F0 CPU	✅	main and sdk (180,061 functions) lift with no unsupported instruction (ARMv8.3 pointer authentication and LDAPR added). Differential tests against Unicorn pass.
F1 OS	✅	Boots on TotK Recomp's Horizon host with the Switch 2 differences: RomFS, save, audio, controller.
F2 NVN 2	✅	700 NVN 2 entry points answered; the game loop runs. 51 new command buffer calls (mesh shaders, VRS, DLSS, push constants…) are accepted but not recorded yet.
F3 Shaders	✅	All 4,820 Ampere shader stages of the first 3D scene go through Eglantine's Ampere-to-Maxwell lowering and TotK Recomp's translator to SPIR-V.
F4 Vulkan	✅	The title screen and the tutorial's 3D scene render.
F5 Playable	🚧	Controller, guide movies (VP9) and push constants work. Open: a GPU fault some minutes in on NVIDIA, the black destructible terrain (its geometry stage, #45), some textures, performance outside the tutorial.

The plan, phase by phase: docs/bananza-plan.md. What is open right now: Roadmap to playable.

How it works

flowchart LR
    subgraph offline["At build time, on your PC"]
        exefs["Your dump: main + sdk<br/>(ARM64)"] --> lifter["Lifter<br/>recomp/"] --> c["C code"] --> clang["Clang"] --> exe["dkb.exe"]
    end
    subgraph runtime["At run time"]
        exe --> host["Horizon host<br/>threads, files, audio, input"]
        exe --> nvn["NVN 2 front end<br/>runtime/nvn_*"] --> vk["Vulkan back end"]
        sass["Ampere shaders"] --> lower["Eglantine lowering<br/>Ampere → Maxwell"] --> xlate["Translator<br/>tools/xlate"] --> spirv["SPIR-V"] --> vk
    end

The longer version is in docs/architecture.md (shared with TotK Recomp) and docs/bananza-shaders.md (the NVN 2 shader work).

How to help

Each open problem is a separate, well-bounded job with its own issue. Pick one, say in the issue that you are on it, and keep each pull request to one topic. Issues labelled in progress are already taken, and the top of the roadmap says what is being worked on right now.

No code needed, only your PC and your own copy of the game:

• #3 Test on your GPU. Everything so far was checked on one NVIDIA card. Runs on AMD, Intel and other NVIDIA cards, with logs, show what breaks there.
• #7 Play past the tutorial and report where it stops.
• #9 The GPU fault after the first guide movie: seen on three NVIDIA drivers (617.14, 617.42, 621.01); runs on AMD and Intel would show whether it is NVIDIA's.

Code (help wanted):

• #5 Checkerboard textures on some rock surfaces. The Switch 2 GOB layout (f4f7b17) fixes the gold rock in the tutorial cave; the other surfaces still need a check.
• #6 NVN 2 calls not recorded yet: mesh shaders, VRS, DLSS and others.
• Symbols. Function names help debugging. They come from GRAnimated/DKBananza, which welcomes contributions too.

Your first contribution, step by step:

1. Build from your own dump (Building from source).
2. Run it as in docs/dkb-testing.md and note how far it gets on your machine.
3. Report it on #3 or #7, or pick an issue above.

Before you open a pull request, read CONTRIBUTING.md. Its hard rule: nothing that came out of the game goes into the repository, not in commits, issues or pull requests. Run python tools/check_content.py --staged before committing; CI runs the same check. Questions go to Discussions. Everyone taking part follows the code of conduct.

Support the project

If you want to support the work without writing code, tips go to ko-fi.com/lucasblippng. A tip pays for time on the project; it buys no game files, builds or early access, and everything stays open source here. Starring the repository and sharing it with people who know GPUs, ARM64 or the Switch also helps.

Building from source

The toolchain is TotK Recomp's (docs/building.md): MSYS2 UCRT64 Clang, Ninja, Python 3.12 and the .NET SDK for the shader translator. With the Bananza ExeFS and RomFS from your own dump:

.venv\Scripts\python tools\build_xlate.py
.venv\Scripts\python recomp\gen.py --exefs <exefs> --out generated\dkb100 --modules main,sdk --patches recomp\patches-dkb100.txt
.venv\Scripts\python tools\dkb_expected.py --exefs <exefs> --name dkb100 --display 1.0.0
.venv\Scripts\python tools\dkb_pack_romfs.py --dir <romfs folder> --out build\extracted\dkb100\romfs
.venv\Scripts\python tools\build_game.py --version dkb100 --expected tools\data\expected-dkb100.json --exefs <exefs> --romfs build\extracted\dkb100\romfs

Everything the build writes stays under build\ and generated\, which git ignores. The game commits about 14 GB (13.5 GiB at the start and 13.75 GiB after 40 minutes, rising about 6 MB per minute; longer sessions are untested), so 16 GB of RAM plus a large page file is the minimum for now and 32 GB is comfortable. Running and testing: docs/dkb-testing.md.

FAQ

Can I play it? Partly. One hand-played run went from the title screen through the tutorial, its cutscene and the first stage to its end on an RTX 5060 Ti, with drops while a new area loads; other cards are untested and it can still crash. Follow the roadmap or the devlog.

Is there a download? Of the installer, on the release page. The executable is made from the game's own code, so it cannot be shared. Everyone builds it from their own dump; the installer does this for you (docs/installer.md).

Which version of the game? Base 1.0.0 and update 3.2.0 (title version 458752, the newest). The installer takes either a .nup file (the container Eglantine and Eden load; with the 3.2.0 update inside it builds 3.2.0) or ExeFS and RomFS folders. Other updates are refused by their hashes. The 3.2.0 build installs and boots, and held 60 fps for 150 s at the start on an RTX 5060 Ti, but nobody has played it yet. Add-on content (DLC) has a reader (an aoc-<n> folder beside the executable, docs/dkb-testing.md) checked against synthetic packs and a real one, but it has not been tried in the game.

Linux? Preview. The release page carries DKB-Setup-<version>-linux-x86_64.tar.gz: the sources and a setup script, not a binary. You install the system packages and it builds the game from your dump. The build from source is verified on AMD and NVIDIA GPUs (docs/installer.md, "Bananza Linux and macOS packages").

macOS? Preview. DKB-Setup-<version>-macos-arm64.zip is the same kind of package. It builds and boots on Apple Silicon with MoltenVK: the game reaches the mode select (docs/building.md, "macOS"). It is not verified beyond that, and the destructible terrain is missing until the geometry stages have a vertex-stage replacement.

Why GPL? The shader lowering comes from Eglantine (Eden Emulator Project), which is GPL. Files that came from TotK Recomp keep their MIT terms.

How is AI used? Most of the code and documentation is written by AI coding agents (Claude Code), as in TotK Recomp, and checked by running the game and the differential tests. AI-assisted pull requests are welcome; you are responsible for having read and run them.

Credits and origin

DKB Recomp is built on TotK Recomp (Tears of the Kingdom, Switch 1) by valentderah and its contributors (MIT, kept in LICENSE-MIT). It uses Eglantine's Ampere shader lowering (GPL-3.0-or-later, runtime/third_party/eglantine/) and Ryujinx's shader translator (MIT, vendored with MacNativeGames' patches), plus the other projects in THIRD_PARTY_NOTICES.md. The whole is under LICENSE.

• TotK Recomp by valentderah, the base of everything here, and the projects it builds on: LAS Recomp, MacNativeGames, nxnative, SavageWindRecomp, Ryujinx, deko3d, hactool and the rest listed in THIRD_PARTY_NOTICES.md.
• GRAnimated/DKBananza for the game's symbols and research.
• Eglantine (Eden Emulator Project) for the Ampere-to-Maxwell shader lowering and its Switch 2 notes, and Mesa NAK for the SM70+ encodings both build on.
• libvpx for the movies.
• Switchbrew for the Switch 2 GetInfo ids, and the Switch homebrew community.

License

DKB Recomp as a whole is under the GNU GPL v3 or later, because it includes Eglantine's GPL Ampere shader lowering (runtime/third_party/eglantine/). The files that came from TotK Recomp keep their MIT License; third-party code keeps its own license (THIRD_PARTY_NOTICES.md). The license grants nothing for Nintendo's game.

DKB Recomp is an independent, non-commercial fan project, not affiliated with or endorsed by Nintendo. Donkey Kong Bananza and Nintendo Switch 2 are trademarks of Nintendo.