Rust 3DS Template

An example project demonstrating how to compile and run Rust programs on the Nintendo 3DS using ctru-rs.

Requirements

A nightly version of Rust is required to use this project. If you don't have Rust installed or don't have a nightly compiler, check out rustup.rs.

Next, you will need Xargo to facilitate cross-compilation to the 3DS.

Finally, you will need the most recent version of devkitARM.

Preparation of the requirements

Installing Rust

If you don't have Rust installed (macOS & Linux):

`$ curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain nightly`

If you have already installed rustup:

`$ rustup default nightly`

Installing Xargo

`$ rustup component add rust-src`
`$ cargo install xargo`

Installing devkitARM

As of this writing, the current version of devkitARM is r48 and the current version of libctru is 1.5.0.

A detailed tutorial on how to set up devkitARM can be found on the 3dbrew wiki.

On macOS & Linux, devkitARM requires two environment variables to be set:

$DEVKITPRO = /path/to/devkitPro/ (usually /opt/devkitpro/)
$DEVKITARM = $DEVKITPRO/devkitARM

Usage

Use the included Makefile to build your program. Under the hood, make calls xargo to create a custom sysroot containing cross-compiled versions of the Rust core libraries, as well as a limited version of the Rust standard library. xargo caches the sysroot after it has been built for the first time. Once the sysroot is in place, a Homebrew Launcher-compatible 3dsx version of your program will be generated.

Running make will build your program in release mode. Running make test will open your program in the Citra emulator if you have it installed. Running make send will send your program to your 3DS via 3dslink (press Y in the Homebrew Launcher to receive the program).

Troubleshooting

I get an error saying that the 3ds target can't be found when I run xargo build

Recent versions of Rust require you to set the $RUST_TARGET_PATH env variable to the directory where your target spec is located. The Makefile does this automatically when you invoke it, or you can manually set the variable yourself.

std or <some other crate> is failing to build

Nightly Rust moves fast and things tend to break a lot. If you want to use a known-working nightly, try the one listed in the travis config file for ctru-rs. And feel free to file an issue detailing the error at the repo too!

I'm running my homebrew in Citra and I don't see any error message if my program panics

You need to enable Debug SVC output in Citra's logger. There are two configuration files in ~/.config/citra-emu: sdl2-config.ini and qt-config.ini. The first is for the normal citra executable and the second for citra-qt. Add Debug.Emulated:Debug to the log_filter variable for whichever version you intend to use. The Makefile calls the sdl2 version by default when running make test.

I got hello world working, but now what? Is there documentation for how to do anything else?

Not quite yet, but we're working on that. Feel free to browse the list of example programs in the meantime.

You should also become familiar with libctru's documentation if you aren't already. It will help you understand what the current ctru-rs APIs are doing, plus you can use raw libctru functions directly via the ctru-sys crate if you want access to anything not yet exposed in ctru-rs.

FenrirWolf / rust3ds-template