Verbose mode startup I've been having sporadic issues where my Macbook Pro Retina hangs at startup.  I started up in verbose mode and it always hangs at this message.

AppleUSBMultitouchDriver::checkStatus - received Status Packet, Payload 2: device was reinitialized


After several minutes it continues with these two message.

IO80211Controller::dataLinkLayerAttachComplete():  adding AppleEFINVRAM notification
IO80211Interface::efiNVRAMPublished():  


What do those messages mean?
AppleUSBMultitouchDriver


is your touchpad, it has some problems but eventually it does it, however, I would recommend the Internet recovery (cmd-opt-r) to reinstall the driver.

The 


  IO80211Controller


is your Network interface 802.11 making a note.