The biopic based on the life of Gregg Allman is beginning to take greater shape.

The names of some of the principal members of the cast, including the actors who will portray the rock legend's best friend and his mother, have been announced.

Billboard reports that Chank Middleton, Allman's long-time confident and assistant, will be played by Aldis Hodge (of TV's 'Leverage') as a young man and by Charles Dutton ('Longmire') as an adult. Kathy Baker ('Saving Mr. Banks') will portray Allman's mother.

'Midnight Rider,' based on Allman's memoir 'My Cross to Bear,' will begin shooting on February 24 in Savannah, Ga. The screenplay traces both the Allman Brothers Band frontman's rise to fame, and his stunning realization at age 64 that health issues would consume him if he did not straighten out his life.

Last month it had been revealed that Tyson Ritter will portray the youthful Allman, while William Hurt will portray him as an adult. Wyatt Russell is set to play Allman's late brother Duane. Also appearing in the film are Eliza Dushku, Bradley Whitford, Zoey Deutch and others.