My question is very similar to this one (Can I plug a 120 volt generator into a 240 transfer switch with a modified cord/connector?), but I'd like to know whether DDS's answer is code-legal under the 2014 NEC.
To make sure it's clear what I'm asking about, I'd like to use a 120V portable generator to feed a 120/240V panel. There are no 240V loads, so I would like to simply install an interlock between the main breaker and the backfeed breaker to avoid installing an entire transfer switch panel. The loads throughout the building are within range for the generator, so I'm not worried about overloading it, but I would like for both busbars in the panel to receive power. I would use a 2-pole breaker, but both screw terminals would connect to the same wire from the generator.
Is this code-legal?