You will need to sand off the loose paint and start over. Depending on the exact condition of your cabinets this could be a complete removal of the latest layer of paint or a complete trip to raw wood. In many cases a complete strip to raw wood isn't needed but this is the best way to assure good adhesion.
After sanding the chipped areas, and maybe everything else, you need to apply a good primer. I recommend an oil base for better adhesion. After the primer has dried you can repaint.