To which Sailfish OS version were you updating? Is your Gemini PDA just running Sailfish OS or is it dual boot? By recover do you mean get your data off device or just get it working again?
Don’t know whether this thread offers you any help in your predicament:
https://forum.sailfishos.org/t/how-to-fix-gemini-pda-device-boot-loop/5191/5