Sega Dreamcast Toolchains Maker (<tt>dc-chain</tt>) with MinGW-w64/MSYS2

This document contains all the instructions to create a fully working toolchain targeting the Sega Dreamcast system under MinGW-w64/MSYS2.

This document applies only on the newer MinGW-w64/MSYS2 environment provided by MinGW-w64.org. For the legacy MinGW/MSYS environment, check the mingw.md file.

Introduction

On MinGW-w64/MSYS2 system, the package manager is the pacman tool. All preliminary operations will be done through this tool.

The MinGW-w64/MSYS2 environment exists in several different flavors. Everything has been tested using the Microsoft Visual C++ Runtime, also known as MSVCRT. The newer UCRT (Universal C Runtime) hasn't been tested. MSVCRT packages are accessible using the mingw-w64 prefix, as shown below in the document.

We are now using 64-bit packages, but MSVCRT packages also exists in 32-bit. For this reason, the ${arch} keyword will be used in the document. As soon as you see this ${arch} keyword, you will have to replace it:

• 32-bit: i686
• 64-bit: x86_64

For example, if you see mingw-w64-${arch}-toolchain and you are working with 64-bit packages, you will have to read as: mingw-w64-x86_64-toolchain.

Please note also, all versions prior to Windows 10 were dropped on this environment. If you need support for older OS, you need to use the MinGW/MSYS environment instead.

Installation of MinGW-w64/MSYS2

1. Open your browser to MinGW-w64.org and choose the download MSYS2 distribution. Download the installer file msys2-${arch}-${date}.exe (e.g.msys2-x86_64-20241208.exe) from the MSYS2 repository.
2. Run msys2-${arch}-${date}.exe then click on the Next button. In the Installation Directory text box, input C:\dcsdk\ or something else, but the directory don't accept spaces. The Installation Directory will be called ${MINGW_ROOT} later in the document. Click on the Next button to continue.
3. Click on the Next button again, then click on the Finish button to start the MSYS2 Shell.

The MinGW-w64/MSYS2 base environment is now ready. It's time to setup the environment to build the Dreamcast toolchains.

Update of your local installation

The first thing to do after installing is to update your local installation:

pacman -Syuu

At the end of the process, a similar message to this one should be appear:

warning: terminate MSYS2 without returning to shell and check for updates again
warning: for example close your terminal window instead of calling exit

This just means the pacman runtime has been updated. Close the terminal as requested. Restart the MSYS2 Shell and run the same command again:

pacman -Syuu

This should update all the packages of the MinGW-w64/MSYS2 environment.

Installation of required packages

The packages below need to be installed to build the toolchains, so open the MSYS2 Shell and input:

pacman -Sy --needed base-devel patch diffutils mingw-w64-${arch}-toolchain mingw-w64-${arch}-autotools mingw-w64-${arch}-texinfo mingw-w64-${arch}-libpng mingw-w64-${arch}-libjpeg-turbo mingw-w64-${arch}-libelf mingw-w64-${arch}-freetype mingw-w64-${arch}-freeglut

Installation of additional packages

Additional packages are needed, if you don't have them installed in your system already:

pacman -Sy git python

Git is needed right now, as Python will be needed only when building kos-ports, but it's better to install these now.

By the way you can check the installation success by entering something like git --version. This should returns something like git version X.Y.Z. Same applies for Python, using python --version.

Preparing the environment installation

1. Open the MSYS2 Shell by double-clicking the shortcut on your start menu (or alternatively, double-click on the ${MINGW_ROOT}\mingw${arch}.exe file, e.g. ${MINGW_ROOT}\mingw64.exe).
2. Enter the following to prepare KallistiOS:

            mkdir -p /opt/toolchains/dc/
            cd /opt/toolchains/dc/
            git clone git://git.code.sf.net/p/cadcdev/kallistios kos
            git clone git://git.code.sf.net/p/cadcdev/kos-ports
   

Everything is ready, now it's time to make the toolchains.

Compilation

The dc-chain system may be customized by setting up a Makefile.cfg file in the root of the dc-chain directory tree. If this is desired, read the main README for more information on setting up custom options for the toolchain; however, in most circumstances, the stable defaults already present in Makefile.dreamcast.cfg will be fine.

Building the toolchains

To build the toolchain, do the following:

1. Start the MSYS2 Shell if not already done.
2. Navigate to the dc-chain directory by entering: cd /opt/toolchains/dc/kos/utils/dc-chain/
3. (Optional) Copy and alter the Makefile.cfg file options to your liking.
4. Enter the following to start downloading and building toolchain: make

Now it's time to have a coffee as this process can be long: several minutes to hours will be needed to build the full toolchain, depending on your system.

Removing all useless files

After everything is done, you can cleanup all temporary files by entering:

make distclean

Fixing up Newlib for SH4

The ln command in the MinGW-w64/MSYS2 environment is not effective, as symbolic links are not well managed under this environment. That's why you need to manually fix up SH4 Newlib when updating your toolchains (i.e. rebuilding it) and/or updating KallistiOS.

This is the purpose of the provided fixup-sh4-newlib.sh script.

Before executing it, edit the file to be sure the $toolchains_base variable is correctly set, then run it by entering:

./packages/fixup-sh4-newlib.sh

Next steps

After following this guide, the toolchains should be ready.

Now it's time to compile KallistiOS.

You may consult the README file from KallistiOS now.