Watch Pro 2 emulator
The emulator runs CMF Watch Pro 2 firmware on your computer. You can use the watch face and menus, try a custom app, or test a firmware update without a physical watch.
Browser preview
Section titled “Browser preview”Open the Watch Pro 2 browser emulator in a recent desktop version of Chrome or Edge. Stock firmware starts automatically. The first boot downloads the virtual storage and can take a moment. Watch log shows the guest’s progress. Use the touchscreen and crown, change brightness, or simulate battery, motion, GPS and optical sensor readings. Stock starts at the highest manual brightness in the watch’s own settings. The browser brightness slider adjusts the rendered display separately. The virtual speaker is on by default. If your browser blocks autoplay, tap or click the emulator to start audio. Use Watch sound under Simulation → Display to mute it. If the virtual watch runs slowly, audio stretches to keep pace while preserving pitch. Battery level sets the reported percentage in stock firmware. With a custom app, the slider changes the simulated battery voltage and the app decides how to report it.
Choose Display test from Boot preset to run a bundled custom firmware. Press the crown to change the pattern’s color. Hard reset to stock discards the running session and boots stock again. Under Custom firmware, Advanced boot files lets you supply a different virtual NAND image or override the prepared base files. Use the camera button to save the circular display as a transparent PNG. Turn on Include frame in screenshots under Display to include the case.
Open FMC watch faces to browse the full Watch Pro 2 catalog. Search by title or creator and sort by newest, most downloaded, or most flashed. Choose a face, then select Apply watch face to install it at boot. Applying restarts a running watch. To use a local face file, stop the watch, select the file under Watch face, and start it again. To try your own build, select Custom firmware, then select a Watch Pro 2 AOTA under Firmware package, or select the application and companion SDFS separately under Raw application files.
Select Bad Apple from Boot preset to run the bundled demo. For an example of a custom Zephyr application, see the Bad Apple source and case study. For Bluetooth OTA and recovery tests, use desktop QEMU.
On phones and devices that report limited memory, the browser limits display updates to about 30 fps to reduce work. The watch firmware still runs in software, so boot times and animation speed depend on the host device. The bundled Bad Apple preset uses a clock setting tuned for playback. Use a custom firmware boot or desktop QEMU for tests that depend on guest timing.
Base firmware files
Section titled “Base firmware files”The browser includes the stock files needed to boot. Use Advanced boot files when your test needs a different starting image. The emulator uses its bundled version for each file you leave out.
| File | What it does |
|---|---|
app.bin |
Stock application used when booting stock. A custom app is selected through the main firmware inputs. |
nor.bin |
The small flash image containing boot parameters and application partitions. Custom app and resource files are placed in this image. |
nand-defaults.bin |
The larger flash image containing resources and settings. Virtual NAND supplies a replacement for this file. |
compat.bin |
The emulator’s compatibility ROM, which provides the services the watch app expects at boot. |
nand-id.bin |
The chip identification table used by the NAND driver. |
wfc-index.txt |
Texture information used to render stock watch faces. |
Desktop emulator
Section titled “Desktop emulator”| Page | What you will do |
|---|---|
| Installation | Install the command line tools, download the QEMU and ROM archives, and check the host libraries. |
| First boot | Create the virtual storage from the reference firmware, boot stock, and open the watch window. |
| OTA and recovery | Transfer an update over simulated Bluetooth and check the installed app after reboot. |
Run uv run cmf-watch-utils emu faces --search "LCD" --sort downloads to
browse FMC from the desktop CLI. Copy the face’s id and add
--fmc-face ID to your stock emu run command. For a file on your computer,
use --watch-face FILE. Both replace Activity Mood for that run.
Profiles
Section titled “Profiles”| Profile | Where the watch starts |
|---|---|
wp2-stock |
Stock firmware 1.0.0.73, after language selection. Start here. |
wp2-onboarding |
The same firmware, at first-time setup. |
Use the Watch Pro 2 profiles only for board JX402. They share the same virtual hardware and use different starting storage.
The preview has booted stock, Bad Apple, and Tilt Mouse on Windows. Its virtual recovery can restore a broken app in QEMU. Real-watch bootloader behavior, electrical faults, and recovery after power loss remain outside that test. See Recovery & boot modes.