Getting Started with Dreamcast development

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This article is actively being worked on

Work in progress - items to be added and/or edited: Setting up debug link, building and burning a CD-R, setting up a first project, setting up an IDE, etc.


This article will cover the entire beginning process: starting from zero to having a working dev environment with debug link (serial or IP) and self-booting CD-R. This guide will cover the process for the following platforms:

  • Microsoft Windows 10 via Windows Subsystem for Linux
  • macOS on Intel or Apple Silicon systems with the Homebrew package manager installed
  • Debian- and Ubuntu-based Linux distributions using the default apt package manager
  • Fedora-based Linux distributions using the default dnf package manager
  • Arch-based Linux distributions using the default pacman package manager

Need help?

Important note: This guide aims to remain up to date and work on all of the above platforms, but keeping instructions for such a variety of platforms up-to-date can be difficult. If you run into any errors or other challenges while following this tutorial, or simply need clarification on any of the steps, feel free to ask for assistance on the message board and we would be happy to aid you and update the guide for the benefit of future readers and others in the community.


Before we get started, let's define several terms:

The toolchain is a set of programs which turns your code into an executable file for your Dreamcast console. The toolchain includes:

  • GCC, a C/C++/Objective-C compiler
  • binutils, an assembler and linker
  • newlib, a C library
  • gdb, a debugger

The toolchain includes a compiler for the Dreamcast's main SH4 CPU, and optionally a compiler for the ARM-based AICA sound processor. Your operating system may already have versions of these programs installed to compile code for your computer, but we will need to build a "cross-compiler" for compiling specifically for the Dreamcast.

KallistiOS or KOS is an open source development library and pseudo-operating system for the Dreamcast console. It is the best documented and most widely used development kit in the homebrew community. KallistiOS's very flexible license allows both homebrew and commercial use with no restrictions other than a requirement to include credit for its use in your project, and indeed almost all commercially sold indie Dreamcast titles use it. There are others in existence, like libronin and libdream, as well as the older development kits Katana and Windows CE created by Sega and Microsoft for use in retail games, but this guide will only cover the setup and use of KallistiOS.

kos-ports is a repository including various libraries which integrate with KallistiOS. We will download and compile these libraries as well.

The debug link is a generic term referring to a hardware accessory to facilitate quickly running and debugging your programs. IP-based links include the Dreamcast's Broadband adapter and LAN adapter accessories, and serial-based links include the Coder's cable, which is a cable that can connect the Dreamcast's serial port to your computer via USB or serial. This guide includes instructions for setting up and using the the Broadband adapter and a USB-based coder's cable.

dc-tool and dcload are a pair of programs to facilitate using a debug link. dc-tool runs on your computer and links to a Dreamcast running dcload-ip or dcload-serial. With this setup, you can quickly load programs, read console feedback, load assets, transfer data, redirect I/O, handle exceptions, debug problems, and so forth.

Choosing a debug link solution

If you are building the toolchain for the purpose of building existing programs from source with little to no modifications, then a debug link setup might not be necessary for you. You may simply build programs to burn directly to CD-R. However, if you are planning to actively develop for the Dreamcast, then a debug link is a critical component. While Dreamcast emulators are mature and accurate enough to play the vast majority of the system's games library without issue, many critical bugs may show up on a real Dreamcast system, but not on a Dreamcast emulator. Therefore, it is highly recommended to test on a real system as much as possible. It's also possible to load software off of a Serial SD card adapter, but without an active link to a computer, debugging and stepping through programs as they execute is significantly more challenging.

Presented below is a table comparing the different options available for a debug link. Due to the cost, potential buyers may want to factor in the ability to play multiplayer games with their purchase. Thus, for comparison, we have included information about the Modem with DreamPi as well, but understand that the Modem with DreamPi cannot be used as a debug link.

Comparison of various Dreamcast connectivity options
Device: Broadband adapter (HIT-400 or HIT-401)
Realtek RTL8139C chipset
LAN adapter (HIT-300)
Fujitsu MB86967 chipset
Modem with DreamPi USB Coder's cable Serial Coder's cable
Useful for dev? Yes, supports dcload-ip Yes, supports dcload-ip,
but BBA is superior and cheaper
No, only useful for online multiplayer gaming Yes, supports dcload-serial Yes, supports dcload-serial
Cost $100 - $200 and up on used markets $200 and up on used markets,
due to extreme rarity
Kit prices vary, around $100 Varies on used markets, uncommonly sold
RetroOnyx sells for $85
Varies on used markets, uncommonly sold
Can make DIY? No No Yes Yes Yes
Performance Up to 100 megabits/s Up to 10 megabits/s Up to 56 kilobits/s Up to 1500 kilobits/s Up to 120 kilobits/s
Games support Some games: Phantasy Star Online, Quake III Arena, Toy Racer, POD SpeedZone, Propellor Arena, Unreal Tournament
Some browsers: Broadband Passport, PlanetWeb 3.0
No games
One browser: Dream Passport for LAN
All multiplayer games with network support
All web browsers
NO multiplayer games support NO multiplayer games support
Homebrew support Homebrew utilities like dcload-ip Homebrew utilities like dcload-ip Homebrew utilities don't support, only multiplayer games Homebrew utilities like dcload-serial Homebrew utilities like dcload-serial

Setting up and compiling the toolchain with the dc-chain script


First, we'll need to install dependencies before building the toolchain. Below we have provided commands to install these dependencies on various systems. Many of the packages will likely already be installed on your system, but we have provided an exhaustive list for good measure.

macOS 13 Ventura on an Intel or Apple Silicon processor

First, make sure you install Apple Xcode, including the Command Line tools. You will also need to install several other packages for which we'll include instructions assuming you have installed the Homebrew package manager on your system.

brew install wget gettext texinfo gmp mpfr libmpc libelf jpeg-turbo libpng meson libisofs

Important Note for Apple Silicon users: On Apple Silicon, Homebrew installs libraries to a path not included by default by the compiler. If you haven't added these to your ~/.zprofile, then add the following lines now and reload your session (or run them in your Terminal session whenever you compile KOS):

export CPATH=/opt/homebrew/include
export LIBRARY_PATH=/opt/homebrew/lib

Debian/Ubuntu-based Linux

sudo apt install gawk patch bzip2 tar make libgmp-dev libmpfr-dev libmpc-dev gettext wget libelf-dev texinfo bison flex sed git build-essential diffutils curl libjpeg-dev libpng-dev python3 pkg-config libisofs-dev meson ninja-build

Fedora-based Linux

sudo dnf install gawk patch bzip2 tar make gmp-devel mpfr-devel libmpc-devel gettext wget elfutils-libelf-devel texinfo bison flex sed git diffutils curl libjpeg-turbo-devel libpng-devel gcc-c++ python3 meson ninja-build

Arch-based Linux

sudo pacman -S --needed gawk patch bzip2 tar make gmp mpfr libmpc gettext wget libelf texinfo bison flex sed git diffutils curl libjpeg-turbo libpng python3 meson

Other Linux distributions

If you're using a different Linux- or Unix-based system besides the one above, you may need to reference your distribution's package database and package manager documentation for the equivalent package names and commands necessary for your system.

Creating a space for your toolchain installation

Create the path where we'll install the toolchain and KOS, and grant it the proper permissions:

sudo mkdir -p /opt/toolchains/dc
sudo chmod -R 755 /opt/toolchains/dc
sudo chown -R $(id -u):$(id -g) /opt/toolchains/dc

Cloning the KOS git repository

Clone the KOS git repository to your system:

git clone /opt/toolchains/dc/kos

Configuring the dc-chain script

Enter the dc-chain directory:

cd /opt/toolchains/dc/kos/utils/dc-chain

You'll need to choose one of the following pre-made toolchain configurations. The testing version uses GCC 13.1.0 with Newlib 4.3.0, the stable version uses GCC 9.3.0 and Newlib 3.3.0, and the legacy version uses GCC 4.7.4 and Newlib 2.2.0. We suggest trying to use the testing or stable version. The latest version has more features, while the stable version has long been used by the community and is known to work well. Run one of the following commands to make your choice:

(for GCC 13.1): mv 
(for GCC 9.3):  mv 
(for GCC 4.7):  mv 

Now, you may configure options to your liking by using a text editor. You may alter the makeopts parameter to the number of threads available on your CPU to speed up the compilation, if desired. However, if you run into errors during compilation, you may want to set makeopts=-j1, as on some operating systems the toolchain may fail to build with a higher setting.

Preparing the toolchain

Run the download and unpack scripts:


Compiling the toolchain

Now we will compile the toolchain. At this point, we have the option of building both the main CPU SH4 compiler and the AICA sound processor ARM compiler, or we can skip the ARM compiler and just build the SH4 compiler. Thankfully, KallistiOS includes a prebuilt sound driver, so the ARM compiler is only necessary if you're wanting to make changes to the sound driver or write custom code to run on the sound processor. To build only the SH4 compiler:

make build-sh4

To build both the SH4 and the ARM compilers:


This process can take anywhere from minutes to a few hours depending on your CPU and number of threads available. When successfully finished, the toolchains will be ready.

Afterwards, if desired, you may also compile the GNU Debugger (gdb) as well:

make gdb

The GNU Debugger is now installed along with your toolchains.

Cleaning up temporary files

After building everything, you can clean up the extraneous files in your dc-chain directory by entering:


Configuring and compiling KOS and kos-ports

Setting up the environment settings

Enter the KOS directory:

cd /opt/toolchains/dc/kos

Copy the pre-made environment script into place:

cp doc/ 

For most users, the default settings will suffice. However, advanced users may the to your liking if you'd like to change compile flags or alter paths. If you'd like to have multiple KOS versions installed or multiple toolchain versions installed, you can set up different files corresponding to these different configurations by altering the paths. Run the source command on the desired file to select that configuration prior to compiling your project.

You will need to run the source command to apply the KOS environment settings to your currently running shell. Run the following now, and whenever you open a new shell to work on Dreamcast projects:

source /opt/toolchains/dc/kos/

Building KOS

Build KOS:


KOS is now built.

Building kos-ports

Clone the kos-ports repository to your system:

git clone --recursive /opt/toolchains/dc/kos-ports

Run the script to build all of the included ports:


kos-ports is now built.

Building the KOS examples

Enter the KOS examples directory:

cd /opt/toolchains/dc/kos/examples/dreamcast

Build the examples:


All of the example programs provided with KallistiOS are now built.

Running an example program through a debug link

TODO: Give a tutorial on compiling dcload/dc-tool, setting up a serial, USB, or IP debug link, and running 2ndmix demo on real hardware.

Download and burn the latest versions of dcload-ip or dcload-serial -- the IP version includes improved DHCP support, so there is no longer a need to configure things beforehand.

Run one of the examples from the kos/examples/dreamcast directory with the following command:

dc-tool-ip -t <dreamcast IP address> -x example.elf

Run dc-tool-ip without any parameters to get additional options.

Burning an example program to CD-R

TODO: Explain how to build mkdcdisc and write 2ndmix demo to CD-R and run on a Dreamcast console

mkdcdisc can be used to easily generate a burnable self-boot CDI image. Build mkdcdisc:

git clone
cd mkdcdisc
meson setup builddir
meson compile -C builddir
./builddir/mkdcdisc -h

and create a CDI image from your compiled ELF like so:

mkdcdisc -e MyProgram.elf -o MyProgram.cdi

Then you can burn the CDI file using DiscJuggler (Windows-only, but also works through WINE), ImgBurn with the CDI plugin, or the cdiburn *nix script floating around out there. (document this better)

Creating your first project

TODO: Explain how to create a new DC project folder with Makefile, adding an external library, create a basic program, and compile it

Further reading

TODO: Links to articles for using gdb, integrating the dev setup with an IDE, etc.