I would take him to a psychologist and or therapist. Finding out a little bit more about him and how his brain really works can go a long way.
Having some professional help can give us as parents the tools to work smarter not harder. This can make all the difference in the world.

Recalling the way that my parents so naively dealt with me is very sad. I have ADD big time. I'm grateful for the advances in psychology that have been made in the last 30 years. (I'm 43) (My parents are great and brilliant people, but they had no idea about what they were dealing with. I think many times they did more harm than good.) Now I'm raising my own 4 teenagers. One has Autism and ADD and another is also ADHD. Sometimes understanding the intricacies of ADD or other psychological quirks that we might have go a lot further than taking over-simplified suggestions like "take away video games" or "make him walk to school' and leaving it at that. Kids do need consequences to teach them, but they can learn 1,000 x more if the consequense is coupled with a parent that understands how ABA therapy works and can take the time to consistently and patiently work through things with their kid. My Autistic kid is graduating high school and just got accepted to BYU-I. He's brilliant, but we sure do worry about his being able to make it when it comes to the getting up and getting to where he needs to be. It's scary to think about. (Yes he has walked to school a few times because he missed the bus. Lol) It has taken a lot of work to get this far. I'm not saying your kid has ____fill un the blank______, I'm just saying that you really would do well to go to a psychologist, or therapist, or both. There's no shame in that at all. (It costs time and money though.)