Setting up Development Environment

Setup

• Install devkitPro. If it's already installed, give it an update, it can't hurt. On Windows there's a GUI installer. On Linux/Mac there's a perl-script.
• Install the 3dsxtools on top of devkitPro according to the website.
• On Linux/Mac cd into your devkitPro folder and execute:

git clone https://github.com/smealum/ctrulib

• If you're on Windows you can download ctrulib as a zip and extract it into your devkitPro folder.

Note: devkitPro/ctrulib/libctru contains ctrulib itself, and devkitPro/ctrulib/examples contains a few 3DS homebrew examples.

Adding some environment variables

• Under Windows: go to System properties, Advanced system settings, Environment variables.
  • Add an environment variable named CTRULIB. Set it to the path to ctrulib.
    • Example: CTRULIB -> C:\devkitPro\ctrulib\libctru
  • You also need to add devkitARM/bin to the PATH environment variable.
    • Example: PATH -> [previous value of PATH];C:\devkitPro\devkitARM\bin

• Under Linux/Mac:
  • Add the following to your ~/.bash_proflle or equivalent:

export CTRULIB=<path to ctrulib/libctru>

Building ctrulib

In the form under which it's provided, ctrulib needs to be built before you can build homebrew.

Open a terminal (cmd window under Windows) and browse to ctrulibs directory (the one you entered in the CTRULIB variable of the previous step). Run the following commands:

make clean
make

If everything goes right, a lib folder should be created with a file named 'libctru.a' in it.

Building the examples

You can build from the examples provided with ctrulib.

• arm11u: simple homebrew example
• sdmc: demonstrates how to access files on the SD card
• mic: demonstrates how to read sound from the microphone
• gpu: demonstrates how to render 3D geometry with the GPU

Building homebrew for distribution

To build your homebrew, it works the same way as for building ctrulib. Open a terminal, browse to your homebrew's folder and run make.

• This will build a .elf file and a .3dsx file together with an icon. The icon and .3dsx file are the format required for the Homebrew Channel.

• To build a Gateway-compatible .3ds file you need to strip the .elf file and use makerom on it (with the provided RSF file):

arm-none-eabi-strip [ELF file]
makerom -f cci -o [.3ds file] -rsf [RSF file] -target d -exefslogo -elf [ELF file] -icon [icon file] -banner [banner file]