gb-starter-kit
A customizable and ready-to-compile bundle for Game Boy RGBDS projects. Contains your bread and butter, guaranteed 100% kitchen sink-free.
Downloading
Downloading this repository requires some extra care, due to it using submodules. (If you know how to handle them, nothing more is needed.)
Use as a template
You can make a new repository using this one as a template or click the green "Use this template" button near the top-right of this page.
Cloning
If cloning this repo from scratch, make sure to pass the --recursive flag to git clone; if you have already cloned it, you can use git submodule update --init within the cloned repo.
If the project fails to build, and either src/include/hardware.inc/ or src/include/rgbds-structs/ are empty, try running git submodule update --init.
Download ZIP
You can download a ZIP of this project by clicking the "Code" button next to the aforementioned green "Use this template" one. The resulting ZIP will however not contain the submodules, the files of which you will have to download manually.
Setting up
Make sure you have RGBDS, at least version 0.4.0, and GNU Make installed. Python 3 is required for most scripts in the src/tools/ folder.
Customizing
Edit project.mk to customize most things specific to the project (like the game name, file name and extension, etc.). Everything has accompanying doc comments.
Everything in the src folder is the source, and can be freely modified however you want. The basic structure in place should hint you at how things are organized. If you want to create a new "module", you simply need to drop a .asm file in the src directory, name does not matter. All .asm files in that root directory will be individually compiled by RGBASM.
There is "basic" code in place, but some things need your manual intervention. Things requiring manual intervention will print an error message describing what needs to be changed, and a line number.
The file at src/res/build_date.asm is compiled individually to include a build date in your ROM. Always comes in handy, and displayed in the bundled error handler.
If you want to add resources, I recommend using the src/res folder. Add rules in the Makefile; there are several examples.
It is recommended that the start of your code be in src/intro.asm.
Compiling
Simply open you favorite command prompt / terminal, place yourself in this directory (the one the Makefile is located in), and run the command make. This should create a bunch of things, including the output in the bin folder.
While this project is able to compile under "bare" Windows (i.e. without using MSYS2, Cygwin, etc.), it requires PowerShell, and is sometimes unreliable. You should try running make two or three times if it errors out.
If you get errors that you don't understand, try running make clean. If that gives the same error, try deleting the deps folder. If that still doesn't work, try deleting the bin and obj folders as well. If that still doesn't work, you probably did something wrong yourself.
See also
If you want something more barebones, check out gb-boilerplate.
Perhaps a gbdev style guide may be of interest to you?
I recommend the BGB emulator for developing ROMs on Windows and, via Wine, Linux and macOS (64-bit build available for Catalina). SameBoy is more accurate, but has a much worse interface outside of macOS.