you will have to trench along both sides of the drive, put the wall in the ground and then build it up high as you need. then fill with gravel. you MUST get all the old gravel out and fill with a good base, otherwise the deep gravel will be to soft to drive on and you may spin out.

also, will the drive not be above grade to teh sides of it? if so you will want the walls to be higher than the drive to keep someone from accidently running off the side.

also, if the ground is not good enough to hold the wall in place you may be forced to use concrete. not a cheap route at all!

what about the other end of the drive? is raising it going to adversely affect water run off? you don't want to raise the drive only to have that cause water to run back into the house!