Those headers are as I recall all part of Broadcom's release at https://www.broadcom.com/support/videocore https://www.broadcom.com/support/videocore. The rest

Those headers are as I recall all part of Broadcom's release at https://www.broadcom.com/support/videocore https://www.broadcom.com/support/videocore. The rest is a matter of looking at register traces and lot's of hard work on Kristina's part.