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August 15-16 2020

NuttX Online Workshop

Bringing NuttX to the FPGA

Brennan Ashton

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@btashton

QuickLogic EOS S3

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Agenda

NuttX Online Workshop

  • State of open source FPGA tooling
  • Running NuttX on FPGAs
  • Emulation with Renode
  • QuickLogic EOS S3

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What are FPGAs?

NuttX Online Workshop

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What are FPGAs?

NuttX Online Workshop

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What are FPGAs?

NuttX Online Workshop

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Open Source Toolchains for FPGA

NuttX Online Workshop

“The GCC for FPGAs”

https://symbiflow.github.io/

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Open Source Toolchains for FPGA

NuttX Online Workshop

“The GCC for FPGAs”

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Building an SoC

NuttX Online Workshop

https://github.com/enjoy-digital/litex

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Building an SoC

NuttX Online Workshop

https://github.com/enjoy-digital/litex

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Building an SoC

NuttX Online Workshop

FuseSOC

“cores never been so much fun”

https://github.com/olofk/fusesoc

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Building an SoC

NuttX Online Workshop

SERV

“SERV is an award-winning bit-serial RISC-V core”

https://github.com/olofk/serv/

How many cores do you want?

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NuttX on FPGAs

NuttX Online Workshop

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Board Bring-Up without Hardware

NuttX Online Workshop

https://renode.io/

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NuttX Online Workshop

nvic: IRQControllers.NVIC @ sysbus 0xE000E000

priorityMask: 0xE0

systickFrequency: 61440000

IRQ -> cpu@0

cpu: CPU.CortexM @ sysbus

cpuType: "cortex-m4f"

nvic: nvic

uart: UART.PL011 @ sysbus 0x40010000

-> intrCtrl@7

size: 0x1000

m4mem: Memory.MappedMemory @ {

sysbus 0x0;

sysbus 0x20000000 //mirror

}

size: 0x80000

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EOS S3 Programmable Logic

NuttX Online Workshop

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NuttX Online Workshop

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Board Bring-Up without Hardware

NuttX Online Workshop

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EOS S3

NuttX Online Workshop

https://www.crowdsupply.com/quicklogic/quickfeather

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EOS S3

NuttX Online Workshop

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EOS S3 Programmable Logic

NuttX Online Workshop

  • AHB-to-Wishbone bridge
  • SDMA Interface
  • Interrupt interface
  • Access to IO pads

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EOS S3 Programmable Logic

NuttX Online Workshop

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EOS S3 Programmable Logic

NuttX Online Workshop

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EOS S3 Programmable Logic

NuttX Online Workshop

Create a /dev/fabric device for controlling the operation of the programmable logic

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Create a user space utility eoss3fb to reconfigure the FPGA fabric

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EOS S3 Programmable Logic

NuttX Online Workshop

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EOS S3 Programmable Logic

NuttX Online Workshop

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EOS S3 -- Where are we?

NuttX Online Workshop

  • Initial port supporting the M4F -- Merged
  • IOMUX and Basic Clock Management -- Merged
  • FPGA manager device -- Proof-of-Concept
  • Support for Wishbone Bus -- In Progress
  • Renode Support -- Minimal

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NuttX Online Workshop

Thank you!​