2007 Denali XL

I have a weird brake issue. My brakes squeak when they are cold. And will get louder as the SUV comes to a stop. The dealer states that this is normal until the brakes get warm. And they do quiet down after a few miles. But I have never had a squeak like this on any other vehicle. The rotors are smooth and what I can tell the pads are good. After I get the oil changed the brakes are quiet even when cold for a dew weeks and then bake to the same issue. Any one have any suggestions?

replace the rotors, calipers and soft brake lines problem solved or deal with the noise