Install

Status

• The system is built: kernel, system image, the watch app, sync, Connect, signed updates.
• All of it runs in an emulator (QEMU, an emulated MIPS processor) and passes automated tests, including updates with a power cut and a rollback to the previous version.
• On a real watch (so far one), PaceOS live runs: loaded from a computer over USB into RAM only (fastboot boot), nothing is written to the watch's storage, and a restart brings back the original system. That watch's whole storage was backed up first and the backup verified.
• Verified on the watch: the display and the PaceOS interface, the button, the touch screen controller (use with a finger not confirmed yet), Wi-Fi (connects to a home network, HTTPS downloads at about 1 MB/s), Bluetooth (PaceOS Connect from Google Chrome on this site: pairing with the code shown on the watch, encrypted settings – for example changing the watch's language from the browser), GPS (the receiver delivers position data and sees satellites indoors), the microphone, the battery reading, and downloading an update with its signature verified.
• Not verified yet: permanent installation, an outdoor run with a GPS fix recorded, the heart-rate sensor (on the stock system it goes through a separate sensor chip with closed software), vibration (the driver runs, but nobody has confirmed feeling it yet), installing an update on the watch, battery life, Gadgetbridge on a phone, Bluetooth headphones and the browser installer.
• The bootloader decides: a locked one (unlocked: no, as the manufacturer ships it) refuses booting from RAM (fastboot boot) and writing – no tool gets past that. An unlocked one (unlocked: yes) allows both. The watch PaceOS runs on has an unlocked bootloader. The browser installer, which shows the bootloader state without writing anything, is not published yet.

The planned path

The rule: nothing is written to the watch's storage until it is verified that everything works and that there is a way back. Each step has its own check, and the next step starts only when it passes.

1. Inspection and backup. Over USB, read the bootloader state and the firmware version. Then copy the watch's whole storage (eMMC) to a computer and verify the copy with SHA-256 on both sides. Nothing is written.
2. RAM boot. A test system, PaceOS live, is loaded into memory only (fastboot boot). It shows itself on the screen, brings up networking over USB and takes a hardware inventory. Holding the button for 6 s reboots into the stock system. The watch's storage stays untouched.
3. Hardware bring-up. Automated checks: display, touch, button, vibration, battery, GPS, heart rate, Wi-Fi, Bluetooth, headphones.
4. Power. Current measured idle, with the screen on and with GPS, against the stock system.
5. Field test. Distance error below about 2 % on a known track, heart rate against a chest strap, a FIT file accepted by Strava.
6. Install. Only now is anything written to the watch – and only with a tested way back to the stock system. Data (runs, music, settings) has its own partition.
7. Updates after that. Each new version is signed and written to the other system partition (A/B). The watch tries it; if the new system does not come up or fails its health check, the watch goes back to the previous one by itself. A power cut while writing does no harm.

What you will need

• An Amazfit Pace (A1602 or A1612) with its charging cradle and USB cable. Not the Pace 2, the Stratos or other models.
• A computer with USB.
• A charged battery.
• For the setup afterwards, a browser – see which browsers work.

The exact steps and computer requirements will be added when the installer is published.

What is needed before it is available

1. Bring up the heart-rate sensor, verify vibration and finger touch, measure power and battery life.
2. Test it in the field: an outdoor run with a GPS fix, recorded and uploaded.
3. Test permanent installation, installing an update on the watch and going back to the stock system from the backup.
4. Verify the browser installer (PaceOS Flasher) on a real watch and publish it.

Until this is done, do not install PaceOS on a watch, even if you find a way to do it by hand.