Windows CE Dreamcast Community Edition (wince-dc)

Windows CE Dreamcast Community Edition (wince-dc)

A real, windowed Windows CE desktop - running on a Sega Dreamcast. The Dreamcast shipped a stripped-down Windows CE 2.12 that retail games booted into and never exposed. Windows CE Dreamcast Community Edition takes that same on-disc CE runtime and turns it into something you can actually use: a multitasking windowed desktop and an in-progress TCP/IP stack over the Broadband Adapter - all baked into a standard bootable Dreamcast disc.

It is fully self-contained: the SH-4 PE compiler and the entire CE image toolchain are vendored in this repo. One cmake invocation goes from source to a bootable disc.gdi. No Platform Builder, no SDK install, no CD key.

• DCWin desktop shell - a windowed, multitasking desktop composited on the PVR2 / Direct3D: move / resize / minimize / maximize windows, a Start button, taskbar, and a mouse cursor. Every app runs in its own CE process.
• Built-in apps - Explorer (browse \, \Windows, \CD-ROM; launch binaries), Task Manager (live process + RAM view), Clock, Calculator, a memory tester, and a winsock network tester.
• Networking over the stock CE stack (work in progress) - a universal link shim (mppp.dll) aims to let the stock microstk.exe + winsock.dll run over Ethernet instead of dial-up PPP, with DHCP/ARP/DNS handled in the shim (DHCP option-6 → the Dreamcast's own flash ISP config → a public resolver). Both link backends - the Broadband Adapter and a W5500/MACRAW over SPI transport - are still being brought up and not yet working end-to-end.
• Self-contained CMake build - vendored SH-4 cl.exe + the CE image tools (makeimg, romimage, …). Produces retail (silent) or debug (serial console) images, and a standard bootable GDI. Prerequisites: CMake ≥ 3.20 and a generator (Ninja). The pair bundled with Visual Studio works out of the box - nothing else from VS is used. PowerShell is used for the disc-imaging steps (Windows host).

# configure (point -DCMAKE_MAKE_PROGRAM at ninja if it isn't on PATH)
cmake -G Ninja -S . -B build

# 1) just the SH-4 modules -> build/modules/ (dcspi.dll, mppp.dll, dcshell.exe, dcw* apps)
cmake --build build

# 2) the bootable OS image -> build/0winceos.bin
cmake --build build --target image

# 3) the full chain -> build/disc/disc.gdi
cmake --build build --target gdi

# example: a SCIF serial-console image (over the working retail DLLs) with a game on the disc
cmake -S . -B build -DKERNEL=debug -DEXTRADATA=path/to/game
cmake --build build --target gdi

The build produces a standard multi-track build/disc/disc.gdi that boots on real Dreamcast hardware:

• GDEMU / MODE / USB-GD-ROM - copy the disc.gdi + its track files onto the SD card / image and select it from the menu.
• Burned disc - for a GD-R / GDEMU-exact layout, use toolchain/make-gdi-real.ps1 to rebuild against a real CE-game GDI (matches the original IP.BIN + track geometry).

The default image boots straight to the DCWin desktop. For diagnostics, build with -DKERNEL=debug and watch the Dreamcast serial (SCIF) console.

See toolchain/README.md for build internals.

This project builds on the Sega "Dragon" Windows CE for Dreamcast SDK (vendored). The shell, networking shim, and SPI driver are original work; the CE kernel and system modules are the stock SDK binaries. Don't redistribute the vendored SDK binaries outside the spirit of this research project.