conferences/sfscon2020.mdwn

   1 ## Why a Libre 3D CPU / GPU / VPU?
   2
   3 * Study of SoCs (Allwinner, Rockchip, NXP) shows none are fully Libre
   4   - Either GPU driver firmware is proprietary, or VPU firmware, or bootloader
   5 * This causes customer product development issues
   6   - https://tinyurl.com/valve-steam-intel
   7 * Businesses are waking up to lack of transparency
   8   - Intel Management Engine (spying backdoor co-processor)
   9   - Spectre, Meltdown, CSME (Chain-of-Trust) issues
  10 * Solution: full transparency.  All source available for everything.
  11
  12 ## How is LibreSOC being developed?
  13
  14 * Using Libre (rather than "open") development practices
  15   - no "I'll release it when it's ready": all development is real-time public access
  16 * No NDAs, no hidden discussions
  17   - we can invite anyone (any expert) to help with review
  18   - free to ask for help anywhere in the world (comp.arch, stackexchange)
  19 * Using litex, nmigen, opencores HDL
  20   - heavily depending on python OO (not possible with VHDL or Verilog)
  21   - leap-frogging ahead by not reinventing the wheel
  22   - yosys converts nmigen to verilog for standard tools.
  23
  24 ## Why is it different from other SoCs?
  25
  26 * LibreSOC is a hybrid CPU-VPU-GPU architecture.
  27   - OpenPOWER ISA *itself* is extended to include 3D and Video instructions
  28   - (SIN, ATAN2, YUV2RGB, Texture Interpolation)
  29   - Only after approval of OpenPOWER Foundation!
  30   - There is no separate GPU or VPU: it really is the same core.
  31   - Massively simplifies driver development and application debugging
  32 * Vectorisation is "Simple-V" (VSX not being implemented)
  33   - VSX is SIMD and is considered harmful
  34   - https://www.sigarch.org/simd-instructions-considered-harmful/
  35
  36 ## What is being developed? (Roadmap)
  37
  38 * First simple core achieved in simulation Sep 2020
  39   - FPGA (ECP5) target followed shortly
  40 * First silicon tape-out 180nm deadline 2nd Dec 2020
  41   - sponsored by NLnet, with help from Chips4Makers Libre Cell Libraries
  42   - layout is entirely libre-licensed tools: coriolis2 from lip6.fr
  43 * Next chip is "SBC" style quad-core
  44   - similar spec to Allwinner A64, Rockchip RK3399
  45   - targets "Pi" boards, smartphones, tablets, Industrial IoT
  46
  47 ## Contact
  48
  49 * Freenode IRC #libre-soc
  50 * Website https://libre-soc.org
  51   - mailing list, git repos, bugtracker etc.