Comment 43 for bug 708286

Sorry for going in circles here. I have one more build which is verified to really blink the caps lock LED when control gets back to the kernel. The last one was branching to the wrong label in one spot, causing the LED to be turned on and never turned off. This will give you a clear way to determine whether you're getting back to the kernel.

http://people.canonical.com/~sforshee/lp708286/linux-2.6.38-10_2.6.38-10.46~lp708286v201107191248/