Mario Kart: Super Circuit Recomp

Experimental preview. This recompilation is a byproduct of developing gbarecomp: the games are the proving ground, while the reusable framework is the larger goal. This is not a finished commercial port, so expect rough edges and please report problems. For more context, read Recomp + AI: 5 Months Later ».

Static recompilation of Mario Kart: Super Circuit for Windows and Linux, with optional 60 FPS, Adaptive Widescreen and Higher Internal Resolution mods.

Special thanks to antimattur for the Mario Kart: Super Circuit decompilation work and for discovering the 60 FPS patch; that foundation made this level of polish possible.

The game ROM and Nintendo GBA BIOS are not included. You must provide your own legally obtained dumps.

Status

The current release is v0.1.11 for Windows x64 and Linux x86_64. The game boots and runs through menus, cup selection, races, and results, and two players can link over the Internet or LAN with emulated link-cable netplay (see docs/NETPLAY.md). v0.1.3 fixes cartridge saving, including Time Trial ghosts, by reporting the correct 64 KB flash chip identity. v0.1.4 fixes delay-sync netplay checkpoint timeouts and keeps the Time Trial speedometer together when Adaptive Widescreen is enabled. v0.1.6 adds optional 2x/3x/4x internal resolution, keeps the course fly-in at the selected sampling density, and extends roadside billboards into the Adaptive Widescreen margins. Sprites and HUD retain their original artwork. v0.1.7 adds 8x and 16x internal resolution and single-player Display view choices. These higher scales can be substantially slower; 4x remains the mod default. In Display, choose 16:9 for a fixed wide view or Adaptive to fit the window or fullscreen display. Native (3:2) deliberately keeps side bars on a wider display. Default (Mods) preserves existing mod choices. The Netplay page's view choice applies separately to online play. v0.1.8 adds the cached HLE track sampler for lower HD rendering cost. Up to 4x is recommended; higher scales are labeled (experimental) and may still run very slowly, even with the optimization.

v0.1.11 fixes course-dependent 16:9 and Adaptive borders across all 40 race courses and four battle arenas, aligns the battle HUD balloons, and includes missing native course-actor and balloon-loss callbacks. The course audit records its validation scope.

This is still an experimental preview; back up important saves and please report repeatable gameplay or presentation edge cases.

v0.1.10 adds resident GPU rendering for supported HD affine scenes and experimental 32x/64x internal-resolution choices. The game retains portable CPU rendering when the GPU path is unavailable or a scene is unsupported. Enhancements remain disabled by default; the resolution mod starts at 4x. Higher scales depend on GPU texture limits, memory and available performance.

Quick start

1. Download the Windows zip or Linux AppImage from Releases.
2. Extract the zip and run MarioKartSuperCircuitRecomp.exe, or mark the AppImage executable and run it.
3. In the launcher, select your Mario Kart: Super Circuit (USA) ROM and retail GBA BIOS.
4. Configure display, audio, controls, and mods, then select Play.

The launcher remembers valid files after the first setup. Enable Skip launcher on boot if you want later launches to go directly into the game.

Included mods

These enhancements are optional and disabled by default:

• 60 FPS Track Rendering updates race presentation at 60 FPS while preserving the game's underlying logic and timing, based on the patch discovered by antimattur.
• Adaptive Widescreen renders additional race content at the sides instead of stretching the original 240×160 image.
• Higher Internal Resolution samples the perspective track at 2x, 3x, 4x, 8x, 16x, 32x or 64x. It works with Adaptive Widescreen; sprites and HUD keep their original artwork. The initial selection is 4x. Higher choices are experimental and depend on your GPU's texture limits, memory and available performance. Supported HD scenes use resident GPU rendering; a portable CPU fallback remains. The widescreen mod also offers Fit to screen and 16:9; an explicit Display view choice takes precedence over this legacy mod.

Open the launcher's Mods page to enable these features. Because they are experimental, please report repeatable visual or gameplay regressions with the course, mode, and character used.

Features

• Native Windows x64 application and Linux x86_64 AppImage
• ROM and BIOS setup through the shared recomp-ui launcher
• Optional 60 FPS, Adaptive Widescreen and Higher Internal Resolution mods
• Two-player link-cable netplay with rollback or input delay
• Keyboard and modern game-controller support
• Windowed and fullscreen play with sharp scaling and optional affine filtering
• In-game settings menu
• Cartridge saves and save states

Controls

GBA control	Keyboard
D-Pad	Arrow keys
A / B	X / Z
Start	Enter
Select	Right Shift
L / R	C / V

Use Shift+F1-F9 to save a state and F1-F9 to load one. Controls can be changed from the launcher.

Building from source

Windows development requires CMake, Ninja, MSYS2 MinGW64, and SDL2:

git clone --recurse-submodules `
  https://github.com/mstan/MarioKartSuperCircuitRecomp.git
cd MarioKartSuperCircuitRecomp

cmake -S gbarecomp -B gbarecomp/build -G Ninja
cmake --build gbarecomp/build --target gba_recompile
pwsh tools/regen.ps1
cmake -S . -B build -G Ninja
cmake --build build --target MarioKartSuperCircuitRecomp

Generation requires the supported ROM revision and a retail GBA BIOS. Their identities and local development paths are documented in baserom.md and game.toml. ROM-derived generated code, copyrighted inputs, saves, and build output remain local and are never included in releases.

Contributors can run pwsh tools/test-attract-gameplay.ps1 for the automated native acceptance routes and pwsh tools/make_release.ps1 -Version 0.1.10 to build a sanitized Windows package. The Linux AppImage build is documented in tools/linux/BUILD.md.

Decomp symbol names (optional)

The generated code and every debug surface — hang traces, dispatch-miss reports, the PC sampler, the TCP symbol query — can be named from the jellees/mksc decompilation, which is pinned as a submodule at third_party/mksc. The tracked files under symbols/ are already imported, so tools/regen.ps1 picks them up automatically; -NoSymbols regenerates without them.

Credit to antimattur for the Mario Kart: Super Circuit decompilation work that made these symbol imports possible.

To re-import after the decomp advances upstream, build it under WSL with tools/decomp/provision.sh and tools/decomp/build.sh (root-free: no devkitPro or apt install needed) and run gbarecomp/tools/symbol_import/import_decomp_symbols.py. The build gates on the decomp reproducing this project's exact ROM SHA-1. Full procedure: gbarecomp/docs/SYMBOL_OVERLAY.md.

The decomp is used only as a source of facts — names, addresses, sizes, and the code/data split its own linker produced. None of its source, comments, or data enters this repository or the build; the submodule pins a URL and commit rather than vendoring code. Upstream ships no license file, which is why the boundary is drawn that tightly.

License

PolyForm Noncommercial 1.0.0 — see LICENSE. Third-party components retain their own licenses.

Legal

This is an unofficial, non-commercial preservation and research project. It is not affiliated with or endorsed by Nintendo. Mario Kart and related names, characters, artwork, and game data are trademarks or copyrights of their respective owners.

No copyrighted game ROM or Nintendo BIOS data is distributed by this project.

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Part of the R.A.I.D. — Retro AI Development static-recompilation community.