CE Runtime Foundation v6.7 pre-alpha

cerf.cx - read more about the project

A universal Windows CE emulator: a virtual hardware platform that boots real CE and Windows Mobile ROMs on modern Windows.

Downloads

Download the WIP build (6.7) from artifacts to use all the latest features, or go to the latest release.

Run launcher.exe: pick a device, and it downloads the ROM bundle and boots it. Running cerf.exe --device=... directly, its command line and its logs are covered in the articles.

Supported boards

SoC	Board / OS	Features
NEC VR4121 MIPS III	Casio Toricomail casio_toricomail Windows CE 2.12
Intel XScale PXA255 ARMv5TE	Falcon 4220 falcon_4220 Windows CE .NET
	NEC MobilePro 900 nec_mobilepro_900 Handheld PC 2000 Windows CE .NET
Freescale i.MX51 Cortex-A8	Ford SYNC 2 ford_sync_2 Windows CE 6
Intel SA-1110 StrongARM	HP Jornada 720 jornada_720 Handheld PC 2000
	iPAQ H3100/H3600/H3700 ipaq_gen1 Pocket PC 2000 Pocket PC 2002
	Siemens SIMpad SL4 simpad_sl4 Handheld PC 2000 Windows CE .NET
	SmartBook G138 smartbook_g138 Windows CE .NET
Intel SA-1100 StrongARM	HP Jornada 820 jornada_820 Handheld PC 3.0 Professional
ARM720T ARMv4T	Microsoft Windows CE Hardware Reference Platform odo Windows CE 2.11 Windows CE 3
NEC VR4102 MIPS III	NEC MobilePro 700 nec_mobilepro_700 Windows CE 2.0
NEC VR5500 MIPS IV	NEC Rockhopper SG2_VR5500 nec_rockhopper Windows CE 6
TI OMAP 3530 Cortex-A8	OMAP 3530 EVM omap_3530_evm Windows CE 7
Philips PR31700 MIPS I	Philips Nino 300 philips_nino_300 Palm-size PC
	Sharp Mobilon HC-4100 sharp_mobilon_hc4100 Windows CE 2.0
Philips PR31500 MIPS I	Philips Velo 1 philips_velo_1 Windows CE 1.0
Samsung S3C2410 ARM920T	Siemens P177 siemens_p177 Windows CE 5
	Device Emulator devemu Windows CE 6 Windows Mobile 5 Windows Mobile 6 WM 2003 SE Windows CE 5
Freescale i.MX31L ARM1136	Zune 30 zune_30 Windows CE 5

Running your own ROM

A ROM boots only if that exact board is implemented in CERF - a matching SoC is not enough. Dropping in your own dump of an already-supported board is covered in the articles.

Bringing up a board CERF does not support is emulator development: the board's memory map, every peripheral its drivers touch, the SoC quirks - all of it implemented in C++, grounded in datasheets, BSP sources and RE, at the quality bar CERF already ships. It is not a config tweak, and not something to hand to an AI and expect magic.

Important

CERF does not accept ROM submissions / board implementation requests. The devices worth doing are done, and so are several that cost months of work and that essentially nobody needs. Bringing up one more board to arrive at one more Windows CE desktop is a very large amount of work for an outcome that already exists. Further submissions will be declined, unless they are genuinely interesting or in demand and I want to do the work.

Building

Requires Visual Studio 2026 with the C++ desktop development workload.

Note

First build on a fresh machine takes 1+ hour. vcpkg compiles dependencies from source before CERF starts linking. This happens once per machine - subsequent builds reuse the cached vcpkg_installed/ tree and finish in a few minutes. Do not interrupt the first build.

Set up the clone (once per machine):

setup.cmd

This initialises submodules, points git at the repo's tracked hooks (core.hooksPath = .githooks - git does not clone hook config, so hooks are inert in a fresh clone until this runs), and reports any missing prerequisite (Python launcher, vcpkg MSBuild integration). Re-run it any time; it is idempotent. setup.cmd -Check reports status without changing anything.

Build via the helper script:

powershell -ExecutionPolicy Bypass -File build.ps1

Or invoke msbuild directly:

msbuild cerf.sln /p:Configuration=Release /p:Platform=Win32

Building the CE-side binaries (optional)

ce_apps/ holds the Windows CE binaries CERF ships, including the Guest Additions display driver. Building them needs a CE toolchain and SDK, which are not required for cerf.exe itself - if you are working on the emulator core, boards, SoCs, the JIT or the host UI, ignore this and use the prebuilt binaries.

To build them, install eMbedded Visual C++ 4.0 (a free, officially archived Microsoft download) and run one script. Full instructions: docs/ce_apps_setup.md.

setup.cmd -Check reports whether the CE toolchain is present.

The website is built from docs/website/ - python tools/build_site.py --serve runs it locally with live reload.

Changelog

Version	Release Date	Changes
v6.7	TBA	📱 Devices ✅ Sharp Mobilon HC-4100: fixed suspend crash 💿 Emulator 🆕 Discord Rich Presence - shows the current device and OS in your Discord profile ✅ Fixed framebuffer not relatching on suspend/resume ✅ Fixed 100% CPU usage and UI deadlocks on Windows XP on non-framebuffer tabs 🚀 Launcher 🆕 UI refresh 💾 CE Apps ✅ CerfDemo: UI and performance improvements ✨ Guest Additions 🆕 High refresh rate support: the guest video mode and host window scanout follow the host monitor's refresh rate 🆕 --screen-refresh-rate flag to set the refresh rate manually ✅ Input devices now run at the proper priority, staying responsive under heavy guest CPU load
v6.6	18 Jul 2026	📱 Devices ✅ Fixed Device Emulator crash booting Windows Mobile 5.2 ROMs 💿 Emulator ✅ Device names with spaces and absolute rom.* paths in cerf.json are now supported 🚀 Launcher 🆕 New-device wizard: create a device profile from your local ROM dump 🆕 Rename a device from its right-click menu
v6.5	17 Jul 2026	📱 Devices 🆕 Sharp Mobilon HC-4100 support (Handheld PC, Windows CE 2.0) 🆕 Casio Toricomail support 💿 Emulator ✅ Fixed Integer scale 2x/3x not resizing the window under "Match guest size" ✅ Fixed moving the window releasing the "Match guest size" lock (now only a resize does) 🚀 Launcher 🆕 Added downloads count sort 💾 CE Apps ✅ Fixed bundled CE2 apps (ROM dumper and others) crashing on launch - their coredll imports were bound by version-specific ordinal instead of by name ✨ Guest Additions ✅ Display driver unified onto a single mips1 build across MIPS devices
v6.4	15 Jul 2026	📱 Devices ✅ Fixed NEC MP700 touch
v6.3	15 Jul 2026	📱 Devices ✅ Fixed a crash when PC Card was re-inserted too fast in DevEmu boards 💿 Emulator ✅ UI updates ✅ Dev only: SDK/Build tools reorganization 🚀 Launcher 🆕 Added multiple bundle repositories configuration ✨ Guest Additions ✅ Fixed IMGFS ROMs regression introduced in v6.0 ✅ Software rendering is fully removed and replaced with hardware rendering. Microsoft dependencies dropped. ✅ Fixed incorrect hardware communication approach for display and shared storage. Now rendering and shared storage is stable.
v6.2	12 Jul 2026	💿 Emulator 🆕 cerf.exe now runs on Windows XP and newer - one binary, XP through 11 ✅ Fixed a crash on startup on every Windows older than 10 1809 (dark-mode init) 🚀 Launcher 🆕 launcher_vista.exe: the launcher for Windows Vista and newer
Previous versions - see the full changelog.

Known Issues

See launcher's boards details database for per-board issues.

Claude Development Environment

Caution

DO NOT USE CERF CODEBASE AS REFERENCE FOR SoCs, BOARDS, PERIPHERALS - AI WRITTEN CODE CAN'T BE TRUSTED!

Built with Claude via Claude Code. Not production-grade.

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CERF ships a Claude Code-based development environment for working on the emulator - including bringing up brand-new boards from their ROMs. Launch it from the repo root with:

run_claude.cmd

It runs Claude Code with a custom system prompt that injects the entire project documentation (CLAUDE.md plus every agent_docs/ reference page) into every agent, so each session starts fully briefed on the project's rules, architecture, and subsystems - no "please read the docs first" needed.

The environment provides the /start-board-implementation skill: drop your ROM into bundled/devices/ (or just point the agent at it) and run the skill. The agent identifies the board and SoC straight from the ROM, checks what CERF already supports, estimates the effort, and - on your go-ahead - starts the bring-up with a cross-session tracking document. So you can literally drop in your ROM and start the procedure of bringing it up.

Warning

The dev environment runs Claude in skip-permissions mode - it can execute anything on your machine without prompting. It also force-kills its own Claude instance, and any clangd.exe, that leaks memory past a threshold. The first launch shows a one-time explanation; press Enter to acknowledge it.

License

MIT. Third-party components and studied references are listed in THIRD_PARTY_NOTICES.md.