Sometimes I think that a problem should be solvable in a few minutes, and then it turns out that it lingers around for months. Very, very frustrating! Such a thing is getting the USB 4.1.1 stack running on the FRDM-K64F board. I have that board since April 2014, and it took me 7 months to get the FSL USB stack running on it :-(.
USB CDC with the FRDM-K64F, finally!