"Currently, the Pica8 driver is released in binary form"none of the interesting low-level drivers is open. none. zero.
If it's based on a Broadcom chip, trust me, they are doing the world a favor by not exposing you to the SoC SDK.
(It's so horribly un-documented that it took a week to figure out how to build it and another two weeks to actually get it to build something that could be used.)
