I had updated my Gemini PDA firmware which was showed in the setting. However, after the updating, my gemini never booted with the planets rotating screen.
How to solve it
First, I sent an email it to the support. They replied me very quickly and said "We are aware of the issue. We are investigating the issue with our firmware over the air (FOTA) ...."
To do this, I had to install libaudio2 rpm package manually to use flash_tool.sh .
And, the flashing part was also tricky. I needed to reboot(press power + silver button) after pressing "Download" button on the tool. I didn't notice that for a long time. But finally, I could have flashed my gemini firmware.
So, I need to setup from the beginning, though...