Restructure the firmware to be more flexible

[mithro]

We need to support;

• Multiple host interfaces;
  • Our current system uses a Cypress FX2 over USB, it is likely we want to support different (cheap) USB solutions.
  • We are have @tariq786 working on an Ethernet host interface.
  • To support the Zybo and Novena devices we'll need a AXI interface too.
• Variable number of capture interfaces;
  • At a basic level, the Atlys and Numato boards both have 2 input and 2 outputs.
  • However, both support the VGA expansion board which adds a third VGA input.
  • There is also the VmodMIB which in theory adds another 4 HDMI bi-directional ports.
  • On the Numato conference board, there is a possibility of the GTP transceivers being used which could support DisplayPort and SDI but use a very different VHDL/Verilog model.
  • The Zybo device only has a single bi-directional HDMI port, but the AXI interface adds a lot of possibility of "virtual" interfaces.
  • The EDID / CEC stuff is probably usefully common between all these systems.
• Variable number (and type) of expansion ports
  • The Atlys and Numato Conference board have compatible VHDCI expansion ports.
  • The Atlys and Zybo have compatible PMOD ports.
  • The Numato Conference board has the GTP transceivers on a DVI port.
  • The Novena uses SATA connectors.
• Various debug / control routing and interfaces
  • It would be nice to get it up the CDC port over USB.
  • It would be nice to get it out on a serial ports, pins, etc.
  • It would be nice to get it out the USB-UART on the Atlys board.
• There are a bunch of subsystems which should be common to all boards though.
  • There should be a debug system which everything uses and automatically exposes the information to everyone.
  • Scalers, JPEG encoders are probably just generally useful.

[mithro]

Capturing some of this stuff in the document at https://docs.google.com/a/mithis.com/document/d/1-oq0WZnooKVja8QQSS2u60MwGc0YNB3TprSNDk-SNVU/edit?pli=1

[mithro]

This issue was moved to timvideos/HDMI2USB-misoc-firmware#155