And with all this extra code...
As always, even with iPhones, iPod touchs, and the iPad, extra code means crashing and Mobile Substrate can solve this too. Should the SpringBoard crash for any reason (which is quite common once let loose on Cydia as there are a large number of SpringBoard extensions) Mobile Substrate will temporarily put the SpringBoard into Safe Mode with SpringBoard extensions disabled, so you can troubleshoot the problem.
If one is trying to troubleshoot a problem that isn't causing Springboard crashes but is suspected of being caused by a Mobile Substrate-using extension, Safe Mode can manually be entered using the SBSettings application available in Cydia by hitting its "Power" button and choosing the "Safe Mode" option.
if you find that your device wont boot you can use this safety feature from a ramdisk or ssh by typing