[LiteX+HDMI2USB] Improve NuttX on LiteX generated SoC & replace HDMI2USB bare metal firmware

Brief explanation

The HDMI2USB project uses "bare metal" firmware running on a soft CPU inside the FPGA. We would like to replace this code with something running on a proper operating system to make it easier to add new features. NuttX is one such option for a lightweight OS.

Expected results

All current HDMI2USB based functionality now works with a firmware running NuttX rather than bare metal C code.

Detailed Explanation

The HDMI2USB-misoc-firmware embeds a LM32 soft-core for controlling and configuring the hardware. See the diagram below;

This soft-core should be able to run NuttX. NuttX is a real-time operating system (RTOS) with an emphasis on standards compliance and small footprint.

A bunch of work has been done on making NuttX work on LiteX.

Further reading

• http://www.nuttx.org/Documentation/NuttX.html#misoclm32

• http://nuttx.yahoogroups.narkive.com/uAcgVEfZ/misoc-lm32-port

• [LiteX] QEmu simulation of a LiteX generated SoC

• [HDMI2USB] Port Linux to the lm32 CPU and support HDMI2USB firmware functionality

Knowledge Prerequisites

• List of
• what knowledge is required
• to complete this project.

Contacts

• Potential Mentors: @shenki @mithro @enjoy-digital
• Mailing list: hdmi2usb@groups.google.com