The broadcom SOC closed source, and it doesn't have public documentation. Also it has a videocore core running a proprietary RTOS called microsoft ThreadX that does bootstrapping and some low level hardware stuff.
Never knew that Microsoft developed and owned ThreadX:
https://en.wikipedia.org/wiki/ThreadX#Products_using_it
The broadcom SOC closed source, and it doesn't have public documentation. Also it has a videocore core running a proprietary RTOS called microsoft ThreadX that does bootstrapping and some low level hardware stuff.