Mush8

A native Mach-O iOS/macOS port of Mario Kart 8 Deluxe, with LAN, online and wireless multiplayer

How does this work ?

the Switch and Apple Silicon both run arm64, so the game's code can almost run as is. a few instructions can't run outside a Switch (the x18 register, system calls, system registers), so this project rewrites them with a tool called nxpatch the rest, most importance peace is nxhost : it plays the role of the Switch's OS (Horizon) for the game, its services (files, saves, controllers, audio, network...) and its graphics API (NVN), which is turned into Metal. The game's shaders are translated to Metal ones and compiled ahead of time too

On macOS, the patched game code is loaded when you launch it. On iOS, and because we don't have JIT, we can't afforc to do that : game code is linked into the app when you build it

On top of that, Mush8 adds LAN Play over the internet (lan-play.com servers) and a wireless mode for nearby devices

Game files

Because Nintendo ninjas are always watching, you will need your own dump :

• prod.keys
• the base game (.nsp)
• update 4.0.1 (.nsp)
• optionally, the Booster Course Pass (.nsp) and a Firmware folder (fonts, Miis)

Mush8 will then asks for them : on macOS pick the folder holding them in the launcher, on iOS import them from the app (or copy them in Files → On My iPhone → Mush8). File names don't matter

Requirements

• Apple Silicon Mac, macOS 14 or later
• Rust toolchain
• Xcode 26 or later

For iOS, also :

• rustup with rustup toolchain install 1.98.1 and rustup target add aarch64-apple-ios --toolchain 1.98.1
• xcodegen (brew install xcodegen)
• an Apple ID to sign the app on iOS (a free one works), or AltStore / SideStore to install the .ipa
• a device on iOS/macOS 26 or later, with 6 GB of RAM or more (8 GB is comfy)

Building

The easy way :

./build.sh

It installs what's missing (Homebrew, Rust...), then asks whether you want the Mac or the iOS version and walks you through the rest. The Mac .app ends up in ~/Downloads/Mush8Output, the iOS one goes straight to your plugged-in iPhone / iPad

By hand, macOS :

./make-app.sh

gives build/Mush8.app. Open it, choose your game files folder and hit Prepare (the first time, it extracts the game and compiles its shaders, a few minutes)

iOS :

./make-ios.sh --install

The signing team is taken from the account signed into Xcode (Settings > Accounts), TEAM=<your team id> overrides it, BUNDLE_ID sets your own app id, FREE=1 signs with the entitlements a free account can get. The first build compiles every shader for iOS, so it takes a while

Or make an .ipa to install with AltStore / SideStore (no signing needed on the Mac) :

./make-ios.sh --ipa

it ends up in build/Mush8.ipa

Multiplayer

Pick a mode in the launcher, under Multiplayer :

• LAN : players on the same network, a Switch can join too
• Online : any lan-play.com server (host:port), Switches on that server included
• Wireless : nearby Mush8 players, no router needed (keep Wi-Fi on)

In the game, the main menu then shows LAN Play, Online Play or Wireless Play

Controls

Any controller works (Switch Pro, Joy-Con, DualSense, Xbox...), each one is a player. On macOS the keyboard works too (WASD stick, arrows d-pad, X/Return A, Z/Backspace B, Q/E L/R, 1/3 ZL/ZR, Tab +), on iOS there are touch controls when no controller is connected

The touchscreen works too : tap the game on iOS, click it on macOS

Motion controls (gyro steering) are off by default, turn them on in the launcher

An iPhone can be a controller too : open Mush8 on it and tap "Use as a controller for a Mac" (no game files needed). It finds the Mac running Mush8 on the same Wi-Fi and joins as the next player with its touch controls (and its motion, if Motion controls is on in the Mac launcher). Turn "iPhone controllers" on in the Mac launcher (it is by default), or on an iPad playing the game

Limitations

• free Apple IDs and the .ipa (AltStore / SideStore) don't get the extended virtual addressing entitlement, so the game runs with a smaller 5 GB memory layout there (a paid account gets the full one)
• Nintendo's online play is gone, use Online (lan-play) instead
• 5 to 8 players split screen is Switch 2 only, so it's hidden
• no amiibo (yet)
• the two WebM videos (credits, Switch 2 dialog) play as a slideshow on iOS

Contributions are welcome !