Managing the Wind: Remote Management for Zephyr Devices With LwM2M

Wed, 01 Jul 2020 00:00:00 +0000

LightweightM2M (LwM2M) by OMA SpecWorks is a device management protocol designed for sensor networks and the demands of a machine-to-machine (M2M) environment. It is designed for the remote management of devices and is based on the Contrained Application Protocol (CoAP, RFC 7252), which itself provides an interaction model similar to the client/server model of HTTP.

The Zephyr RTOS from the Linux Foundation possesses built-in support for LwM2M. In this presentation, you will discover how to leverage LwM2M to manage Zephyr-based devices. You will understand the pros and cons of using Zephyr’s built-in LwM2M client. You will also learn about various LwM2m servers, including the Eclipse Leshan open source project, which you can use to build your own LwM2M management server.

LwM2M features

bootstrapping
Device Configuration
Firmware Update
Fault management
Configuration and Control
Reporting

LwM2M in the Zephyr Arch

IPSP
- Bluetooth profile leveraging 6LoWPAN (IPv6 over BLE)
LwM2M Client
- Runs on QEMU
- Runs on actual board
- requires server

A Server: Eclipse Leshan

Java library for implementing clients and servers
Simple (no framework, few dpenecneies)
Web UI for discovering
build using mvn install
based on Eclipse Californium (an implementation of CoAP)

LwM2m sample

lwm2m is lightweight. net/lwm2m.h.
Includes
main
Setup
Event processing

Demo

Deploy

west build -b nrf52_adafruit_feather samples/net/lwm2m_client -- - DCONF_FILE="prj.conf overlay-bt.conf"
west flash --runner jlink
sudo minicom -D /dev/ttyUSB0 -b 115200

6lowpan and assign IPv6 address

sudo su
modprobe bluetooth_6lowpan
echo 1 > /sys/kernel/debug/bluetooth/6lowpan_enable
hcitool lescan
echo "connect C2:FA:8D:93:21:DD 2" > /sys/kernel/debug/bluetooth/6lowpan_control
ip address add 2001:db8::2/64 dev bt0
ping6 2001:db8::1

Getting and starting Leshan Demo Server

wget
https://ci.eclipse.org/leshan/job/leshan/lastSuccessfulBuild/artifact/le
shan-server-demo.jar
java -Djava.net.preferIPv6Addresses=true
-jar leshan-server-demo.jar

you can read, write and modify values
Some are built into sample
- temperature sensor
- lights

Software Update (OTA) for Zephyr

Wed, 01 Jul 2020 00:00:00 +0000

Zephyr devices can be connected in two possible (direct and in-direct) ways to the internet. Directly using Modem/WiFi/Ethernet medium or in-directly via local radio through Gateways like Linux. Upgrading such Zephyr system in the field is a complex task and must be robust, secure.

This talk will details various possible update solutions available like UpdateHub, Hawkbit, SWUpdate for Zephyr. Using a NXP FRDM-K64F board as an example, we will discuss and demo different possible ways for updating Zephyr system.

Agenda

McuBoot
Updatehub
mcumgr
ZUpdate
ZUpdate -Hawkbit
Future work

Linux vs Zephyra

on linux it handles both download and install
for zephyr this is split into two
- download handled by application
- install is handled by MCUBoot
First we focus on download.
Then we look at install

MCUBoot

Bootloader for Zephyr and mynewt
integrity and security check
multi image boot support
softwre update heavy lifting

MCUBoot Memory Layout

NXP Freedom kit

chosen {
zephyr,code-partition = &slot0_partition;
};
&flash0 {
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
boot_partition: partition@0 {
label = "mcuboot";
reg = <0x00000000 0x00010000>;
read-only;
};
slot0_partition: partition@20000 {
label = "image-0";
reg = <0x00020000 0x00060000>;
};
slot1_partition: partition@80000 {
label = "image-1";
reg = <0x00080000 0x00060000>;
};
scratch_partition: partition@e0000 {
label = "image-scratch";
reg = <0x000e0000 0x00020000>;
};
};
};

Paritions

Mcuboot
slot0
slot1
scratch

MCUBoot operation

conditions: Interrupt swap, request swap, valid image
Video from Youtube

MCUBoot swap

swap status
- three stage operation
- slot1 to slot0

API

image confirmed
write image
request upgrade
erase

Live share

west flash -d ./frdm_mcuboot/

Software Update

Updatehub

What is it?
Polling Mode
Manual mode
Community vs Enterprise

Live Share

~/work/west/native/zephyr/samples/net/updatehub
west flash
~/work/west/native/zephyr/samples/net/updatehub
west flash -bin-file ./build/zephyr/zephyr-signed.bin

Web UI

Overview
Devices
Pakcages
Rollouts

Each rollout has

UID, version, hardware

MCUmgr

Management library for Zephyr and mynewt
OS and hwardware agnostic

Layered modular design

1: img_mgmt,fs_mgmt,log_mgmt,os_mgmt
2: mgmt
3: SMP
4: BLuetooth, Shell, UDP

Reference Screenshots

STM32 target initial slot list
Uploading the OTA image via the Bluetooth interface
STM32 target initial slot list after OTA push

ZUpdate architecture

Configuration Manager
ZUpdate Core
Download Handler
- Hawkbit
- updatehub
- SWUpdate
- Custom
StorageHandler
- SPI NOR
- FLash
- MMC
Low-Level Comm
- BLE
- WiFI
- LoRa

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