## Why a Libre 3D CPU / GPU / VPU?

* Study of SoCs (Allwinner, Rockchip, NXP) shows none are fully Libre
  - Either GPU driver firmware is proprietary, or VPU firmware, or bootloader
* This causes customer product development issues
  - https://tinyurl.com/valve-steam-intel
* Businesses are waking up to lack of transparency
  - Intel Management Engine (spying backdoor co-processor)
  - Spectre, Meltdown, CSME (Chain-of-Trust) issues
* Solution: full transparency.  All source available for everything.

## How is LibreSOC being developed?

* Using Libre (rather than "open") development practices
  - no "I'll release it when it's ready": all development is real-time public access
* No NDAs, no hidden discussions
  - we can invite anyone (any expert) to help with review
  - free to ask for help anywhere in the world (comp.arch, stackexchange)
* Using litex, nmigen, opencores HDL
  - heavily depending on python OO (not possible with VHDL or Verilog)
  - leap-frogging ahead by not reinventing the wheel
  - yosys converts nmigen to verilog for standard tools.

## Why is it different from other SoCs?

* LibreSOC is a hybrid CPU-VPU-GPU architecture.
  - OpenPOWER ISA *itself* is extended to include 3D and Video instructions
  - (SIN, ATAN2, YUV2RGB, Texture Interpolation)
  - Only after approval of OpenPOWER Foundation!
  - There is no separate GPU or VPU: it really is the same core.
  - Massively simplifies driver development and application debugging
* Vectorisation is "Simple-V" (VSX not being implemented)
  - VSX is SIMD and is considered harmful
  - https://www.sigarch.org/simd-instructions-considered-harmful/

## What is being developed? (Roadmap)

* First simple core achieved in simulation Sep 2020
  - FPGA (ECP5) target followed shortly
* First silicon tape-out 180nm deadline 2nd Dec 2020
  - sponsored by NLnet, with help from Chips4Makers Libre Cell Libraries
  - layout is entirely libre-licensed tools: coriolis2 from lip6.fr
* Next chip is "SBC" style quad-core
  - similar spec to Allwinner A64, Rockchip RK3399
  - targets "Pi" boards, smartphones, tablets, Industrial IoT

## Contact

* Freenode IRC #libre-soc
* Website https://libre-soc.org
  - mailing list, git repos, bugtracker etc.