Before installing AsteroidOS to your watch, make sure you are aware of the capabilities and limitations of AsteroidOS on the Asus Zenwatch 2. The following table should summarize the current support of this watch:
Make sure you use the correct Asus Zenwatch 2 ROM.
- Sparrow has a 320x320 1.63-inch screen, 22mm straps and a 380mAh battery.
- Wren has a 280x280 1.45-inch screen, 18mm straps and a 290mAh battery.
Install ADB & Fastboot
On Linux systems
with apt package manager
On Windows systems
sudo apt install android-tools-adb android-tools-fastboot
install this ADB driver from clockworkmod
Download this zip file containing ADB & Fastboot from Android SDK
Extract the content to a folder of your liking.
Navigate to that folder using Windows commandline (cmd.exe).
1. Unlock your bootloader
Installing AsteroidOS requires an unlocked bootloader and entering the bootloader requires ADB in Wear OS.
Enable ADB on your watch with the following steps:
Finally, to unlock the bootloader
- Open the settings app and go to the "About" page.
- Tap the Build number 7 times until Developer options become enabled.
- Go back to the settings menu and then to the "Developer options" page.
- Enable ADB debugging.
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.
- Real installation
While your watch is in bootloader mode, flash the userdata and boot partitions using Linux:
or using Windows:
fastboot flash userdata ~/Downloads/asteroid-image-sparrow.ext4
fastboot flash boot ~/Downloads/zImage-dtb-sparrow.fastboot
fastboot flash userdata %systemdrive%%homepath%\Downloads\asteroid-image-sparrow.ext4
fastboot flash boot %systemdrive%%homepath%\Downloads\zImage-dtb-sparrow.fastboot
- Temporary installation
Reboot to Wear OS, re-enable developer mode and ADB debugging.
Push AsteroidOS to the internal sdcard using Linux:
or using Windows:
adb push -p ~/Downloads/asteroid-image-sparrow.ext4 /sdcard/asteroidos.ext4
Everytime you want to reboot AsteroidOS from Wear OS, run:
adb push -p %systemdrive%%homepath%\Downloads\asteroid-image-sparrow.ext4 /sdcard/asteroidos.ext4
Then, if you are using Linux:
adb reboot bootloader
or on Windows:
fastboot boot ~/Downloads/zImage-dtb-sparrow.fastboot
fastboot boot %systemdrive%%homepath%\Downloads\zImage-dtb-sparrow.fastboot
3. Enjoy your new OS!
Troubleshooting & FAQ
- Fastboot displays "invalid sparse file format at header magic" message when start flashing
This is not a fatal error but expected behaviour. Keep calm and wait for the ~5 minute flash process to finish. Fastboot simply informed you that the partitions it is now flashing where not downloaded in a "sparse" format.
- Flash fails with fastboot crashing or hanging at "invalid sparse file format at header magi" (missing the "c" in magic)
This error often but strictly happend in our testing when using an old fastboot (& ADB below 1.0.39) on Windows systems. If you already had fastboot installed and skipped downloading our supplied zip file, please do so now.
Either overwrite your current ADB & fastboot by extracting the zip into its folder. Or extract to a new folder instead (e.g. automatically to ...\adb_1_0_39+fastboot+ext2simg\) and change directory to that new folder.
- Flash fails or stops during the ~5 minutes process
Smartwatches are prown to loose proper connection to their cradle over time due to sweat corroding the watch pins. Especially on dory (LG G Watch) this is a regular problem.
Cleaning the pins with alcohol or even carefully sanding them (e.g. with a nailfile) can provide a reliable connection again.
- Asus Zenwatch 2 flashed successfully but does not boot
As you may have missed, there are two versions of the Asus Zenwatch 2, codenamed Sparrow and Wren.
Their images are not interchangeable. Make sure a second time you are using the right files.