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LibreBMC

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Todd Rosedahl, IBM�Paul Mackerras, IBM�Michael Neuling, IBM��

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DC-SCM card – an open HW/SW BMC solution

  • Connects and boots an IBM AC922
    • Replaces the existing BMC card
  • BMC is an FPGA
    • Open ISA (POWER ISA)
    • Open Core (microwatt)
    • Open Peripherals with Lite-X
    • OpenBMC firmware
  • Uses the DC-SCM/DC-SCI standards
  • Complete Openness for enhanced security – allows HW security patches in the field

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AC922 BMC Block Diagram

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Architecture – IBM AC922

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BMC

AST2500

Power Supplies

Fans

VRMs

Linux Kernel. In openBMC

App code

and data files

In openBMC

Device Drivers

In openBMC

Self Boot Engine (SBE)

Mem

IO

FSI

NVRAM

I2C

PGOODs

GPIO

Planar

BMC Card

”Boxelder”

I2C

I2C

LPC

Flash

Molex 240

Pin connector

Procs

OCC

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Architecture – IBM AC922 – “BoxArty”

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FPGA

ARTIX-7

Power Supplies

Fans

VRMs

Linux Kernel. In openBMC

App code

and data files

In openBMC

Device Drivers

In openBMC

Self Boot Engine (SBE)

Mem

IO

FSI

NVRAM

I2C

PGOODs

GPIO

Planar

BMC Card

”Boxelder”

I2C

I2C

LPC

Flash

Microwatt

POWER ISA

Molex 240

Pin connector

Procs

OCC

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P9 Witherspoon/AC922

  • Witherspoon has a plugin BMC card called Boxelder
  • Main board is called Sequoia or Redbud
  • Connected via Molex 240pin connector

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Software details

  • Linux kernel running on microwatt
  • Bit banging kernel drivers:
    • FSI
    • I2C
  • Fan controllers via I2C
  • PDBG:
    • CFAM
    • SCOMs
  • LPC:
    • Host console – 16550 UART
    • Host firmware via LPC FW/IPMI BT – being upstreamed

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Status:

  • Fans can be controlled
  • Boots Vanilla Host Firmware!
    • SBE -> Hostboot -> OPAL -> Petitboot -> Ubuntu OS

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Architecture – IBM AC922 – Antmicro DC-SCM

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FPGA

ARTIX-7

Power Supplies

Fans

VRMs

Linux Kernel. In openBMC

Device Drivers

In openBMC

Self Boot Engine (SBE)

Mem

IO

FSI

NVRAM

I2C

PGOODs

GPIO

Planar

Antmicro

DC-SCM

I2C

I2C

LPC

Flash

Molex

240 pin

connector

DC-SCI

Custom

Interposer

App code

and data files

In openBMC

Microwatt

POWER ISA

Procs

OCC

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Interposer Card

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DC-SCM Card

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Connected!

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Installed in Carrier

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Fully installed in AC922

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What's Next

  • Bringup on DC-SCM card – currently ongoing

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  • OpenBMC software stack – Add full support

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  • FPGA Gateware
    • Add full support
    • Performance/Size Improvements

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  • Upstream and CI incorporation

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  • Make this a viable BMC production replacement

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Join us!

  • Get in on the action: https://openpower.foundation/groups/librebmc/
    • The forum and all information is free and completely open to all
  • We meet every other week. One European time slot(10am Central) and one Australian (5pm Central)
    • Agendas and recordings are made public
  • Timeline for Product/Facility Availability
    • You can buy your own AC922 now: https://www-store.shop.ibm.com/shops/ips/product/server-18335-model-gth
  • DC-SCM link: https://www.opencompute.org/documents/ocp-dc-scm-spec-rev-1-0-pdf
  • Lite-X link: https://github.com/enjoy-digital/litex
  • Open POWER ISA link: https://openpowerfoundation.org/tag/power-isa/
  • Microwatt link: https://en.wikipedia.org/wiki/OpenPOWER_Microwatt
  • FPGA Benchmark: https://docs.google.com/document/d/1Z_FAfFPszk8nreLSvssLmDGayXmF4hmh6R8fMxUEZPM/edit�

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Thank you!

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DC-SCM with LibreBMC and OpenBMC – IBM AC922

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Libre BMC

FPGA

replaces

ASIC

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Power Supplies

Fans

VRMs

Linux Kernel. In openBMC

Device Drivers

In openBMC

Self Boot Engine (SBE)

Mem

IO

FSI

NVRAM

I2C

PGOODs

GPIO

Planar (HPM) – AC922

DC-SCM

Card

I2C

I2C

LPC

Flash

DC-SCI

(190+ pins/functions

defined)

App code

and data files

In openBMC

Microwatt

POWER ISA

Procs

OCC