Building a binary

Prerequisite

As far as the author knows, building a PRK binary, or to be exact, preparing a build environment can be done in only Linux. WSL2 should work, too.

If you are a macOS user, try docker instead. (See Docker)

Make sure you have CRuby (MRI) because "Static type checking" by Steep will be invoked in the build process
Setup Raspberry Pi Pico C/C++ SDK
- Follow the instructions on https://github.com/raspberrypi/pico-sdk#quick-start-your-own-project
  - Additionally, you need to run git submodule update --init in pico-sdk directory so that tinyusb submodule locates in it
  - Make sure you have PICO_SDK_PATH environment variable

Clone the prk_firmware wherever you like

(be sure to add --recursive)

git clone --recursive https://github.com/picoruby/prk_firmware.git

Setup (for the first time only)
```
cd prk_firmware/
rake setup
```
Build
```
rake
```
Now you should have prk_firmware-[version]-[date]-[hash].uf2 file in prk_firmware/build/ directory.

You may want PRK Firmware not to be a mass storage device in case that your employer doesn't allow you to bring a USB memory 🙈

If so, you can build a binary including your keymap.rb in this way:

Clone a keymap repository, for example, "meishi2" which is a 2x2 matrix card-shaped keyboard in prk_firmware/keyboards directory
```
cd keyboards
git clone https://github.com/picoruby/prk_meishi2.git
```
Build
```
cd .. # back to prk_firmware/
rake build_with_keymap[prk_meishi2]
```
Now you should have prk_firmware-[version]-[date]-no_msc.uf2 file in prk_firmware/keyboards/prk_meishi2/build/ directory which includes your keymap in code.

You are likely having problems while developing PRK.

These files may give you a clue regarding PRK build system:

prk_firmware
 ├── CMakeLists.txt
 ├── Rakefile
 ├── lib
 │    └── CMakeLists.txt
 └── src
      └── ruby
           └── Rakefile