This is from a previous post I made:
I am not sure if it has been mentioned before, but in addition to the 2 fuel pumps in each main tank, there is a pump bypass valve in the left and right tanks that allow the engine driven fuel pump to suction fuel from the tanks in the event the boost pumps are not working. I believe that this situation would be highlighted by a level B ENG FUEL PRESSURE warning which includes an audio warning.
Additionally, if the boost pumps were not providing flow, they would also give a similar LOW PRESSURE warning. And if all that ice was heading down to the engine, I am sure that the FUEL FILTER clogging warning would have come on.
I can't imagine anything else going on in the cockpit prior to touchdown under normal conditions. The aircraft would be already configured for tank to engine feed (legal requirements) long before the approach and the crossfeed valves would or should be shut. The crossfeed valves are not normally operated on the B777 other than to correct an inflight fuel imbalance.