I use that mode to manually update my phone. It is usually activated by holding the power and home buttons during boot-up. From that symbol, open your keyboard and hold alt-L. This should show a menu. If your phone won't boot all the way go in to the menu and do a factory restore (I don't remember which one it is alt-something). You will have to download your apps again, but since you sign in again your contacts and your calendar and other google linked apps will sync right back up. Hope that helps.
Linear Mode
