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ACPI for Network Switches

Dustin Byford <dustin@cumulusnetworks.com>

LinuxCon NA 2015, Seattle8/18/2015 - 3pm PST

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● Platform bringup at Cumulus

● Hardware description protocols, ACPI

● Platform bringup revised

● Switch specifics

● What’s next?

●

●

Agenda

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Platform Bringup at Cumulus

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Step 0 - The Stare Down

Take the cover off, stare at the switch for at least 10 minutes.

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Step 1 - Boot the OS

Get a JTAG debugger, start from scratch or reverse engineer the existing bootloader.

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Step 2 - Enable Switch Functions

Convert the hardware spec, often a .pdf, into code and configuration files.

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Step 3 - Test

* more later

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Step 4 - Ship

Ship a new version of Cumulus Linux

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Pixels. Retrieved from http://xkcd.com/1416/

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Silverstein, S. (1981) A Light in the Attic. New York, NY: HarperCollins

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ACPI as a Platform Description Protocol

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1. Loggerhead

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1. Loggerhead2. Green

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1. Loggerhead2. Green3. Kemps-Ridley4. Leatherback

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Method (C2K, 1, NotSerialized) { Add (Multiply (Arg0, 0x0A), 0x0AAC, Local0) If (LLessEqual (Local0, 0x0AAC)) { Store (0x0BB8, Local0) } If (LGreater (Local0, 0x0FAC)) { Store (0x0BB8, Local0) } Return (Local0) }

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By Jason Scott on Flickr (textfiles) CC-BY-2.0 (https://creativecommons.org/licenses/by/2.0/), via https://flic.kr/p/66xFow

By Jason Scott on Flickr (textfiles) CC-BY-2.0 (https://creativecommons.org/licenses/by/2.0/), via https://flic.kr/p/66xEK5

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OS

Hardware

Firmware

ACPI

Kernel

Tests Tools

Generic Drivers

InterfaceSpecification

HOWTOGuide

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[traffic on highway picture]

By User Minesweeper on en.wikipedia (Minesweeper) [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], via Wikimedia Commons

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Without ACPI

With ACPI

Steps0, 1

Test ShipPortONIE

PortOS

PortONIE

DescribePlatform

Certify Ship

Standards Based OS Vendor Specific

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Switch Specifics

CPLDs, Switching ASICs, SFF Cages

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CPLD Driver

ACPI _DSD

Fan

Sensor

SFP Cage

CPLD I2C HardwareMFD

GPIOLEDsI2C

0x00: HW Rev

0x01: SFP mux

0x02: Fan PWM

0x03: SFP Prs

0x04: SFP Dis

0x05: S. LED

regmap_read()regmap_write()

devm_gpiod_get()

/sys/class/hwmon

I2C / GPIO

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Switch ASIC

ACPI _DSD

SerDes 0

SerDes 1

SerDes 2

SerDes 3

QSFP Cage

QSFP Lane 0

QSFP Lane 1

QSFP Lane 2

QSFP Lane 3

I2C

GPIO w/Intr.

CPU

x86ARM32

PowerPC

PCIe

LED Bit 42

2 Color LED

ACPI _DSD

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Future Stuff

●

● Standardize everything we can

● Continue to work with hardware vendors

● Improve SFF pluggable (SFP/QSFP) drivers

● Improve testing tools

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Thank You!

© 2015 Cumulus Networks. Cumulus Networks, the Cumulus Networks Logo, and Cumulus Linux are trademarks or registered trademarks of Cumulus Networks, Inc. or its affiliates in the U.S. and other countries. Other names may be trademarks of their respective owners. The registered trademark Linux® is used pursuant to a sublicense from LMI, the exclusive licensee of Linus Torvalds, owner of the mark on a world-wide basis.