[Q] Factory reset after Rooting phone topic

Recently I factory reset my rooted Samsung Galaxy S2 without really thinking. Now on reboot, it seems to be stuck on the ' Samsung GALAXY SII GT-19100' start up screen (with the yellow triangle). I realized after I did the factory reset that it was a bad idea so any help would be greatly appreciated :)
If it helps, I am rooted with Jeboo Kernel