Ran across this:
The (L)ittle (K)ernel Android bootloader
u-boot has always seemed a bit big to me and not so appropriate for a final product. The lk bootloader is a thin, Snapdragon focused bootloader that gives you the basic initial startup, splash screen, kernel loading, and handoff. It looks like there’s basic Beagleboard and ATSAM7 support as well.
The code is here:
http://android.git.kernel.org/?p=kernel/lk.git;a=tree