Linux+Zephyr:IoTmadeeasy

IoTExplodesEverywhere

❑ “Sensorsandactuatorsembeddedinphysicalobjectsandlinkedthroughwiredandwirelessnetworks,oftenusingthesameInternetProtocol(IP)thatconnectstheInternet”-DefinitionbyMcKinsey.

❑ Soundsjustlikeembeddedstuffwe’vebeendoingfordecades!Sowhatchanged?

❑ Nowthere’sabigmarketandtheworldisjust‘ready’.

❑ Unfortunatelythere’snostandard(andprobablywillnotbeoneformanydecades),fragmentationisrunningamok.

LinuxIoT

❑ AroundformanyyearsandbeendoingIoTthingswithitbeforeithadacoolname.

❑ AllprotocolshavetheirreferenceimplementationonLinux(AllJoyn,MQTT,Weave,XMPP,etc)

❑ UnfortunatelyLinuxhasgottenquitelarge

❑ Minimumkernelforembeddedtarget>4MBcompressed

❑ RequiresafewhundredsofGBofflashforageneralpurposeinstall.

❑ Notsuitableforverysmalldevices

Priceiseverything

❑ IfwecouldrunLinuxoneverythingyouwouldn’tbeinthispresentation!

❑ Linuxissecure(hasyearsofscrutinyandprofessionalsecuritypeoplegoaftereverycommitwithafinetoothcomb).

❑ Linuxhasthefullnetworkingstackrequired.

❑ LinuxhastheI/Ocapabilities(everysensor/actuatordriver)

❑ Unfortunatelyyoucan’trunLinuxon$0.5part.

Priceiseverything(cont)

❑ RunIoTona$0.5part(ideally,wecoulddowith$1)

❑ Thisisthesweet-spotformanyapplications

❑ Puta$50deviceoffpremisesandgetlostorstollen,youmightgetabitupset->endupnotbuyingit.

❑ Puta$1deviceoffpremisesandgetlostorstollen->meh.

❑ TurnsoutthatweneedanOSforourcheapdevicesthatisleanerthanLinux.

❑ Manyoptions!

RTOSselection

❑ Abigselectionofchoices,thebigcontenders

❑ FreeRTOS

❑ mbedOS

❑ NuttX

❑ magenta(LK)

❑ None

❑ Zephyr

FreeRTOS

❑ DualLicense-GPLv2withlinkingexceptionorcommercial

❑ SparseAPI-themostRTOSofoldofthemost

❑ Nocommunitydevelopmentforthecore(separate)

❑ Preemptivethreadmodel,optionalMPUprotection

❑ Networkingisanadd-on-nohighlevelframeworks

❑ Suitedforpeoplemovingonfrombaremetal

mbedOS

❑ Apache2,6LoWPanunderpermissivebinarylicense(etc).

❑ Newmbed5RTOS(CMSIS-RTOS-RTX)

❑ Communityinvolvementminimal(ARMfocused).

❑ MINAReventbasedAPI

❑ Completestandardsupport(twodifferentIPstacks)

❑ TiedtothembedOScloudAPI

❑ Mosteasytogetstarted,butnotveryopensourceIMO.

NuttX

❑ BSD3clause

❑ MostLinuxAPIofthemall.

❑ Hasalargecommunitybut80%isMr.Nutthimself

❑ QuitePOSIXcompatible-easiertoportLinuxstuff

❑ IPstackbutnotmuchelseIoTrelated

❑ Largerthantheotheroptions,mostLinuxlike.

magenta(partoffuchsia)

❑ MITlicense

❑ Littlekernel-UsedonAndroidbootloaders.

❑ Justintroduced,communityisdubious

❑ Limitedprioritynumber,standardprimitives.

❑ Networkingstack-couldn’tfigurethisout:)

❑ Googleproject-significantinfantmortality

None(isalwaysanoption)

❑ N/A

❑ N/A

❑ N/A

❑ N/A

❑ N/A

❑ Onlyforthehardcore

Zephyr

❑ Apache2(networkstackApache2)

❑ AdequateRTOSAPI(andnano/microoption)

❑ UnderLinuxFoundation-trueopensource

❑ Networkingstack-IPstack+IoToptions(CoAP)+BLE

❑ Linuxkconfigbuildsystem,feelsrightathome.

❑ Ourselection.

IoTonZephyr.

❑ CoAP,BLE,contiki+tinydtls

❑ Canbeverysmall(smallestnanokernelexampleat8K)

❑ PortingofIoTlibrariespossible

❑ Youcanaccomplishquitealot.

❑ WhataboutLinux?Wheredoesitfitin?

IoTonZephyr(problems)

❑ Security-yourIoTdevicehaskeysandpasswords,howdoyouhandleitbeingstolenbyamaliciousparty?

❑ Convenience-Howeasycanyouupdatethesoftwareonthedevices?Youmighthavedozenonyourpremises.

❑ FutureProofing-Notenoughroominnon-volatilestorageforeveryIoTprotocol.Whathappensifthecompanygoesoutofbusiness?Youhavetochangeallthelightbulbs/securitysystem/etcinsuchacase?

❑ Warringtribes-iPhonevsAndroid-itshouldworkwithmyotherdevicestoo.

Solution:LinuxGateway

❑ LinuxgatewayandslaveZephyrIoTdevices.

❑ LinuxcanrunallIoTprotocols(andwithenoughRAMatthesametime)

❑ Futureproof-Linuxiseasilyupdated,sincepointtodoso.

❑ SoftwareontheIoTdevices?ShoulditbeanIoTstack?Dowestillneedtoupdates/wontheIoTdevices?

Intermission:CheapIoT(1)

❑ CheapMCUwithonchipperipherals

❑ ARMMcore/PIC/ARM/x86/AVR

❑ GPIOs

❑ PWM

❑ Serial

❑ I2C

❑ SPI

❑ Networking(IEEE802.15orZigBeeorWiFi)…

Intermission:CheapIoT(2)

❑ Analogglue

❑ SensorsonI2C/SPIbus

❑ Verypricesensitive

❑ Speedsareusuallylow

❑ Powerbudgetissmall

❑ Lessismore

WhatiftherewasnoIoT(1)

❑ LinuxhasfullI/OcapabilitiesforIoT

❑ Problemisthatthesensorsareremote

❑ WhatifwegotridoftheheavyweightIoTprotocols?

❑ Zephyrdevicesaresimplyperipherals

❑ S/WloadonZephyrdevicesisthesameforthesameSoCnomatterwhatdifferentkindofsensor/IoTdeviceitis

❑ LinuxkernelinterfacesmeanalltheIoTapplicationareinsulatedfromtheunderlyingdevicedetails.

WhatiftherewasnoIoT(2)

❑ Significantlessattacksurfacewithsecurityproblems:

❑ Thedevicesonlycontainenoughkeystoconnectwiththegatewayandhavenovaluableinformation

❑ Thereismuchlesssoftwareonthedevice

❑ Bothendscanbesecuredeitherwithpre-programmedkeysorusingasmart-phoneapplicationoninstalltime.

❑ Thedevicesarebasicallydisposable.

Implementation(bare)

❑ DirectlyaccesstheSoCresources

❑ Registers

❑ Busses

❑ +Nosoftwarebesidesnetworkingandconfiguration

❑ -Performancemightbeimpacted

❑ -Morepowerrequired(tradeoff)

Implementation(classdrivers)

❑ Thinclasslayer

❑ GPIOclassforinstance

❑ Classesforeverykindofperipheral

❑ -MoreS/Wcomparedtobarebones

❑ +Betterperformance

❑ +Lesspowerrequired

Status

❑ Unfortunatelynodemoyet!

❑ TestbedisabeagleboneandanIntelGalileo

❑ KerneldriverprovidesremoteGPIOsnow,I2C,SPItocome

❑ Kerneldriversusesauser-spacehelpertobridgetothedeviceoverBLE.

❑ Pre-configuredkeyswithDTLS

❑ WIP,hopetohaveademoatELC.

Thankyou!

Questions?