According to a report from Billboard, the film is based on Dream Boogie: The Triumph of Sam Cooke, a definitive biography published by Peter Guralnick in 2005. The book was adapted to a screenplay by Dick Clement and Ian La Frenais, both of whom worked as screenwriters on that hokey Beatles musical Across the Universe.
Regardless, Billboard explains that the film will follow Cooke's entire life, from 1931 to 1964, including time spent as a gospel singer, pop star, activist and label head. Knowing that the Across the Universe dudes are involved, we're praying they don't also turn Cooke's life into a goofy musical for tweens.
ABKCO, the company who own Cooke's publishing rights and most of his master recordings, are in charge of the project, meaning the music rights of Sam Cooke have already been secured, so it's just a matter of time before the team hire a director and start casting.