Bomberman Online Recompiled

Bomberman Online — native recompilation

A native C/C++ recompilation of Bomberman Online (Sega Dreamcast, USA, MK-51065 V1.004), built on dreamcomp-style static SH-4 recompilation, with working original online multiplayer via DCNet and a cross-platform Electron launcher.

The original game is © SEGA / HUDSON SOFT. This public repository and its releases contain no copyrighted game data. Release downloads include a prebuilt native executable; players still supply their own Bomberman Online disc image (.chd) for the game's runtime disc reads.

What is here

Path	Purpose
game/bomberman_online.toml	Measured game config for dream-translate (disc SHA-1, load/link address)
src/bomberman_online.cpp	Port registration and device/MMIO handlers
game/bindings.txt	Documented default keyboard/gamepad input bindings
tools/launcher/	Cross-platform Electron launcher (disc browse, Play, online, resolution, controller remap, logs)
tools/dc.sh	Run dreamcomp's CLI with the local toolchain environment
tools/env.sh	Local paths (dreamcomp, Java, Ghidra, libchdr) — no system installs
docs/GAME-INTERNALS.md	Reverse-engineered facts, with evidence and confidence
docs/PLAN.md	Milestones, gates, verified checkpoints

Build

Prerequisites: CMake 3.24+, Ninja, a C++20 compiler, Python 3, and an extracted boot file from your own disc. The dreamcomp engine is vendored at ./dreamcomp; nothing else needs checking out. A windowed build also needs SDL3 and Vulkan (the Vulkan SDK provides glslc); on macOS, MoltenVK and a glslc on PATH (or the repository's libshaderc-driven shim) are enough.

tools/dc.sh setup . --disc "/path/to/Bomberman Online (USA).chd"
tools/dc.sh build .            # headless-capable build
tools/dc.sh report . --frames 600

setup reads the boot binary straight from your image. .gdi and .cue need nothing extra; for .chd, the vendored libchdr is built once on first use so no system package is required.

The game executable is generated into build/game/bomberman-online and is never committed. The generated SH-4 code is compiled as eight translation units in parallel; the build prints a heartbeat with the number of parts finished so a long first build does not look hung.

Launcher

The Electron launcher replaces the old Tk UI. Build and run it:

cd tools/launcher
npm ci
npm start                      # dev mode
npm run selftest               # verify UI renders on all platforms
npm run package                # electron-builder: .dmg/.zip (macOS), .exe/.zip (Windows), .AppImage/.deb/.tar.gz (Linux)

The launcher handles disc selection, Play/Headless/Build/Stop, resolution presets + scale slider, aspect (native/wide), vSync/fullscreen/FPS/sound, online enable/DCNet server/port, TCP reachability test, controller test, remap editor, streaming logs, and settings persistence.

Release downloads are prebuilt: choose your own disc image once and press Play. The bundled native executable starts directly; the launcher does not run CMake, Ninja, Python, a compiler, or a local recompilation. The disc image is passed to the game for GD-ROM reads. The Build action is only for developer/source checkouts; packaged releases do not rebuild. User settings and VMU saves remain in the writable app-data workspace across application updates. The status-bar Check for updates control checks GitHub Releases, downloads the matching Windows/macOS package (or Linux AppImage), verifies its SHA-256 checksum, and installs it after the launcher closes. The macOS helper replaces the `.app` bundle directly, so an ad-hoc/unsigned build can update without Electron's signed-app updater. Linux `.deb` and `.tar.gz` installs use the Releases page; portable AppImages can update in-app. Disc selection, launcher settings, bindings and the VMU are stored outside the application bundle and are retained.

Prebuilt release pipeline

Every release job checks out the boot executable from the private nvd123-YT/bombermanprivate repository, verifies its SHA-1 against game/bomberman_online.toml, and compiles the native game separately for macOS, Windows, and Linux. The compiled executable and its adjacent runtime/frontend assets are bundled into the download. The private assets are never uploaded to public artifacts or releases.

The workflow requires a fine-grained GitHub token stored as the BOMBERMAN_PRIVATE_TOKEN Actions secret in this repository. Grant it Contents: Read-only access to nvd123-YT/bombermanprivate only. Do not put the token in source files.

Online (DCNet)

Original online multiplayer is implemented over the BBA + DCNet:

• Discovery: UDP to dcnet.flyca.st:7655, picks an access point (US East, Europe, South America, US West)
• TCP: framed DCNET\x01 prolog + 2-byte LE length Ethernet frames to the access point
• DHCP: Discover → Offer → Request → ACK (assigns IP via DCNet)
• Flash: seeded with Flycast's ISP + BBA blocks (netmask 0xFFFFFF00, IP 0 = DHCP, valid CRCs)

To play online: create a character in Extras Box first (saves to .dreamcomp/bomberman.vmu), then enable online in the launcher and enter online mode in-game.

Status

Area	State
Disc identification, boot binary, first translation	implemented and verified
Native build	headless + windowed builds verified (macOS via MoltenVK)
Expansion-device probes	all five mapped as absent devices; unmapped memory accesses: 0
Translation coverage	untranslated call targets: 0 after merging modem/BBA function seeds
Audio	larger circular buffer (93 ms) + rate control; stuttering resolved
BBA / DCNet online	RTL8139 implemented, DCNet transport + DHCP handshake working
Game reached title screen	confirmed via scripted input
Character creation	VMU .dreamcomp/bomberman.vmu contains valid BOMBERONLINE save
Online connection	TCP established to DCNet access point; DHCP Offer received
Launcher	Electron: disc browse, Play, online, resolution, controller remap, logs, settings
Packaging	electron-builder: macOS .dmg/.zip, Windows .exe/.zip, Linux .AppImage/.deb/.tar.gz
CI	GitHub Actions: native prebuilt game + launcher packages on macOS/Windows/Linux
Menu rendering	suspected stretch; true widescreen TBD

Repository rules

• No game data committed: .chd, .vmu, .PVR, .AFS, etc. are all in .gitignore
• No credentials, no Ghidra DBs
• No push/publish without authorization
• Nightly releases are built automatically at 00:00 UTC; tag a commit with v* for a formal release