RV64X. An Open Source GPU based on RISC-V
The days of Open Source GPUs will soon be upon us following the path opened by RISC-V CPUs, which allows any company to develop processors and microcontrollers on this architecture without paying royalties.
There are numerous free and commercial IP developments for RISC-V based systems on a single chip (SoC), but the portfolio lacks a graphics option. This will change in a few years, as a group of enthusiasts is developing a new set of graphical instructions designed for 3D graphics and media processing.
These new instructions are based on the architecture proposed by the RISC-V Foundation responsible for the most promising Open Source processor project in the industry. The group calls it RV64X, since the instructions will be 64 bits long and will support support for new data types intended for graphics handling, including vectors, textures, and Z / Frame buffer operations.
Is an Open Source GPU feasible?
The idea is not to compete against NVIDIA, AMD or Intel for the foreseeable future. Instead, the group plans to develop an ISA CPU-GPU that could scale from simple microcontrollers to advanced GPUs that do support modern, more advanced graphics features such as ray tracing, machine learning and computer vision with custom hardware extensions. .
The team - a group of engineers from Pixilica, GOWIN Semiconductor, CHIPS Alliance, and Western Digital - say their motivation and goals are driven by a desire to create a small, efficient design, with custom programmability and extensibility. The RV64X group says its graphics processor will implement a standard microcode graphics pipeline, but will also be able to add custom rasterizers and other functions to support features that are not supported by commercially available GPU designs.
The idea is to offer free intellectual property without competing with commercial offers. It can be implemented in FPGA and ASIC designs and will be free and open source. The initial design will be aimed at low power microcontrollers, but will be able to scale to large graphics units. It will initially support the Khronos Vulkan APIs and will eventually support others such as OpenGL and DirectX.
Developers think that most graphics processors cover the higher levels, such as games or computer vision, but they believe that the ecosystem lacks a scalable graphics core for more conventional applications and with fewer needs (kiosks, billboards, toys, robotics, household appliances, industrial man-machine interfaces…).
This is a very early specification, still under development and subject to change based on feedback from stakeholders and industry. For this, the team will establish a discussion forum. An immediate goal is to build a sample implementation with an instruction set simulator and an FPGA designed as an open source project.
EETimes has published a technical article in case you are interested in seeing the fundamentals and first steps of this Open Source GPU. Initially, a graphics driver designed by RV64X will be used for simple microcontrollers. As the design evolves it could address more demanding applications.
The open source movement that has revolutionized software development is also gaining traction among hardware developers. The first efforts focused on the RISC-V architecture are leading the way and surely an Open Source GPU is just as necessary in the industry as the open source CPU.
