Rapper Meek Mill is the latest name to join 12 O'Clock Boys.
He joins leads Jahi Winston and Teyonah Parris and co-star Will Catlett.
Angel Manuel Soto is the director. Barry Jenkins wrote the initial draft for a script, with the rewrites done by Sherman Payne.
Set at Sony, the project hails from Will Smith and Jada Pinkett Smith's Overbrook Entertainment with Pinkett Smith, her brother Caleeb Pinkett and Clarence Hammond producing. It is based on the 2012 documentary of the same name followed black dirt bike riders in Baltimore as they live life to the fullest while staying ahead of the police.
The scripted feature film will follow Mouse (Winston) "a young boy who wants nothing more than to be a part of the Midnight Clique, a tough group of Baltimore bike riders who rule the summertime streets. As he navigates the challenges of coming of age in a complicated world, he learns the hard way that the choices you make early on can change your life forever."
Mill, whose real name is Robert Rihmeek Williams, the leader of the Midnight Clique.
This will be his studio film debut.
Production begins this week.
Deadline first reported the news.