There are no white papers or even much documentation for the Pi HDMI you have to piece together information and look at existing code and websites.
The basics are:
You use the mailbox API to setup the Video mode you want and get a framebuffer, that much is documented
https://github.com/raspberrypi/firmware ... -interface
The framebuffer is the flat video memory pointer the bits/byte array from that pointer have different layout depending on video mode you select.
That is where most of us started.
There are a number of good assembler sources:
David Welch: https://github.com/dwelch67/raspberrypi
Peter Lemon: https://github.com/PeterLemon/RaspberryPi
If you prefer C my the source code for my article may help:
https://www.codeproject.com/Articles/11 ... he-Pi-part