That's where the boot up sequence terminated. After a little while the O2+ LED turned off. I thought I'd bricked it.
You've perhaps run into the fact that the Linkit and Omega2 use different serial ports and baud rates for their consoles. Your boot log stopped right at the point where Linux switches from the inherited serial configuration to its own.
An odd thing about the Linkit kernel is that it decides which serial port to use based on which on-chip hardware it finds configured (and does this in a way that gets easily confused if you enabled more than one in uboot).
Best guess: it's still on the port you are connected to but now at 57600 baud.