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Hello World

In this section, you will create your first Wii U homebrew application.

Creating a Project​

important

These commands are for Linux/macOS. As a result, Windows users should use the MSys2 application.

First, create a new project folder and navigate into it:

mkdir hello-world
cd hello-world

Next, create the project structure:

mkdir source
touch Makefile source/main.c
tip

Makefile has no file extension — this is intentional.

Your project structure should look like this:

hello-world/
├── Makefile
└── source/
    └── main.c

Writing Code​

Open source/main.c and add the following code:

#include <coreinit/thread.h>

#include <whb/log.h>
#include <whb/log_console.h>
#include <whb/proc.h>

int
main(int argc, char **argv)
{
   WHBProcInit();
   WHBLogConsoleInit();
   WHBLogPrintf("Hello World!");

   while (WHBProcIsRunning()) {
      // Main loop
   }

   WHBLogPrintf("Exiting...");
   WHBLogConsoleDraw();
   OSSleepTicks(OSMillisecondsToTicks(1000));

   WHBLogConsoleFree();
   WHBProcShutdown();
   return 0;
}
tip

This is a minimal Wii U homebrew template that initializes the system, prints "Hello World!", and keeps the application running until it is closed.

The while (WHBProcIsRunning()) loop keeps the application alive. Without it, the program would exit immediately.

Writing a Makefile​

Copy the official Wii U homebrew Makefile template from the devkitPro wut samples:

https://raw.githubusercontent.com/devkitPro/wut/refs/heads/master/samples/make/helloworld/Makefile

Paste it inside the Makefile that you previously created.

tip

This is the standard build system for Wii U homebrew using devkitPro and wut.

You generally do not need to modify it unless you are adding libraries.

Building​

To build the project, navigate to the directory that contains the Makefile and run:

make

If everything is set up correctly with devkitPro, this will generate a .rpx or .elf file.

Running on Wii U​

To run your application:

  • Copy the .rpx file to your SD card
  • Place it in the apps folder inside the wiiu directory on your SD card
  • Launch it from the Wii U Menu

Running it via Cemu is even easier:

  • Launch Cemu
  • File > Load
  • Open the .rpx file

Console emulation isn't perfect so there may be differences between how the code runs on the emulator and real hardware, which is why I recommend only using it to quickly test and debug code.