Install TicWatch Pro 2018/20 (catfish/catfish_ext/catshark)

Hardware Support

Before installing AsteroidOS to your watch, make sure you are aware of the capabilities and limitations of AsteroidOS on the TicWatch Pro 2018/20. The following table should summarize the current support of this watch:

Display Touch Bluetooth Haptics Tilt-to-Wake Light Sensor Always-on-Display Dual-Display Microphone Speaker Compass Heart Rate USB WLAN GPS NFC Cellular
good good good good good good good partial good good good good good good partial bad bad

You can report any hardware support issue here. Use the label catfish/catfish_ext/catshark for issues specific to your watch.


Download AsteroidOS nightly builds

Store the files in your "Downloads" folder so the later commands work

asteroid-image-catfish.ext4 zImage-dtb-catfish.fastboot

Install ADB & Fastboot

On Linux systems with apt package manager

sudo apt install android-tools-adb android-tools-fastboot

On Windows systems install this ADB driver


Download this zip file containing ADB & Fastboot from Android SDK

Extract the content to a folder of your liking.
Navigate to that folder using the Windows commandline (cmd.exe).


1. Unlock your bootloader

Installing AsteroidOS requires an unlocked bootloader. Accessing the bootloader can be achieved via ADB in Wear OS, as described in steps 1.1 to 1.4 below.
You can skip these steps if you are familiar with the manual method to access the bootloader. The different methods are explained on the useful commands page.

Enable ADB on your watch with the following steps:
  1. Open the settings app and go to the System and then About page.
  2. Tap the Build number 7 times until Developer options become available.
  3. Go back to the settings menu and then to the Developer options page.
  4. Enable ADB debugging.

Finally, to unlock the bootloader enter the following commands in a terminal with your watch connected:
adb reboot bootloader
fastboot oem unlock
Follow the instructions on your watch's screen. Please note it may void your warranty.

2. Flash and boot AsteroidOS

Choose your installation type

You can now decide if you want to replace Wear OS definitively or try AsteroidOS as a dual-boot. The "real installation" provides the best experience but it is advised to make a backup of your data first. The "temporary installation" is a good way to try AsteroidOS if you don't plan to use it daily.

  1. Real installation
  2. While your watch is in bootloader mode, flash the userdata and boot partitions using Linux:
    fastboot flash userdata ~/Downloads/asteroid-image-catfish.ext4
    fastboot flash boot ~/Downloads/zImage-dtb-catfish.fastboot
    fastboot continue
    or using Windows:
    fastboot flash userdata %systemdrive%%homepath%\Downloads\asteroid-image-catfish.ext4
    fastboot flash boot %systemdrive%%homepath%\Downloads\zImage-dtb-catfish.fastboot
    fastboot continue
  3. Temporary installation
  4. Reboot to Wear OS, re-enable developer mode and ADB debugging.
    Push AsteroidOS to the internal sdcard using Linux:
    adb push -p ~/Downloads/asteroid-image-catfish.ext4 /sdcard/asteroidos.ext4
    or using Windows:
    adb push -p %systemdrive%%homepath%\Downloads\asteroid-image-catfish.ext4 /sdcard/asteroidos.ext4
    Everytime you want to reboot AsteroidOS from Wear OS, run:
    adb reboot bootloader
    Then, if you are using Linux:
    fastboot boot ~/Downloads/zImage-dtb-catfish.fastboot
    or on Windows:
    fastboot boot %systemdrive%%homepath%\Downloads\zImage-dtb-catfish.fastboot

3. Enjoy your new OS!