Have you resolved this problem? I'm using a COM Express module with ATOM N450, have the same problem with you. It seems that the bootstrap CPU can not kick off the application cpu. The bootstrap CPU sent IPI to kick off the AP, but the trampoline code of the AP be executed. This doens't happen every time. But if it stuck at "Booting processor.....", press a key on the keyboard will make it continue, and everyting seems OK then.