Matter OTA Software Update with Silicon Labs Example Applications#

This page outlines the steps for a scenario that demonstrates the The Over The Air (OTA) Software Update functionality in Matter.

The Over The Air (OTA) Software Update functionality is enabled by default for all Silicon Labs example applications. Its inclusion in an application is controlled by the OTA Requestor component in a Matter Studio project.

Overview#

The OTA Software Update scenario requires the following binaries:

The running image: a regular application built with the default/older software version value. This application will be updated to the one with a higher software version. In the OTA Software Update process it acts as the OTA Requestor.
The update image: a regular application built with a higher software version value.
Chip-tool: the controller that announces the OTA-Provider's address to the application thus triggering the OTA Software Update.
OTA-Provider: the server that carries the update image and from which the OTA Requestor will download the updated software.
Bootloader: Silicon Labs Gecko Bootloader image that supports OTA; supports the external (SPI-flash) or the internal storage option.

The demo scenario requires the use of the Silicon Labs Simplicity Commander tool.

Outline of the steps for the OTA Software Update Scenario#

Create the running image.
Create the update image with software version value incremented.
Create the OTA file from the update image.
Create/obtain a bootloader that supports Matter OTA Software Update.
Start the OTA-Provider passing to it the OTA file. Commission the OTA-Provider.
Bring up your device with the running image, commission the device.
Use the chip-tool to issue the Announce OTA Provider command to the device and trigger the OTA Software Update Process.

Note: In a production environment the Announce OTA Provider command is not used. Instead, the OTA Provider address is configured on the device by the Matter Controller and the device queries the Provider for an available image every 24 hours.

Setting up the OTA Environment#

Setting up the chip-tool#

The chip-tool binary is a part of the Silicon Labs' Matter Hub Raspberry Pi Image available as a part of the Release Artifacts page. For building the chip-tool for Linux or Mac consult the documentation in https://github.com/project-chip/connectedhomeip.

Setting up the OTA-Provider#

The chip-ota-provider-app binary for a Raspberry Pi is a part of the Artifacts package available with the Matter Extension release. For building the chip-ota-provider-app for Linux or Mac consult the documentation in https://github.com/project-chip/connectedhomeip.

Building Application Images Using Simplicity Studio#

The running image and the update image are regular Matter application images and are built using the standard procedure. The only additional configuration required is the use of a higher software version in the update image. The software version is configured in a Studio Matter project by navigating to Software Components -> Silicon Labs Matter -> Stack -> Matter Core Components, clicking "Configure" and setting the "Device software version" and "Device software version string" parameters.

See the following page for detailed steps: build OTA application using studio.

Obtaining the Bootloader binary#

Build or download the Gecko Bootloader binary which can be obtained in one of the following ways:
- Follow the instructions in Creating the Bootloader for Use in Matter OTA.
- Pre-built binaries (only valid for the external SPI-flash storage OTA update) are available on the Matter Artifacts page.
- Bootloader (only valid for the external SPI-flash storage OTA update) is built as a part of any Matter Solution in Simplicity Studio.
Using the Commander tool or Simplicity Studio, upload the bootloader to the device running the application.

Running the OTA Download demo scenario#

Create a bootable image file (using the Lighting application image as an example):

$ commander gbl create chip-efr32-lighting-example.gbl --app chip-efr32-lighting-example.s37

Create the Matter OTA file from the bootable image file:

$ commander ota create --type matter --input chip-efr32-lighting-example.gbl --vendorid 0xFFF1 --productid 0x8005 --swstring "2.0" --swversion 2 --digest sha256 -o chip-efr32-lighting-example.ota

In a terminal, start the Provider app and pass to it the path to the Matter OTA file created in the previous step:

$ rm -r /tmp/chip_kvs_provider

chip-ota-provider-app  --KVS /tmp/chip_kvs_provider -f chip-efr32-lighting-example.ota

In a separate terminal, run the chip-tool commands to provision the Provider:

$ chip-tool pairing onnetwork 1 20202021

$ chip-tool accesscontrol write acl '[{"fabricIndex": 1, "privilege": 5, "authMode": 2, "subjects": [112233], "targets": null}, {"fabricIndex": 1, "privilege": 3, "authMode": 2, "subjects": null, "targets": null}]' 1 0

For Matter over OpenThread, bring up the OpenThread Border Router and get its operational dataset. For Matter over WiFi, bring up the AP.
If the application device had been previously commissioned, hold button 0 for six seconds to factory-reset the device.
Commission the device.
For Matter over OpenThread:
```
$ chip-tool pairing ble-thread 2 hex:<operationalDataset> 20202021 3840
```
where operationalDataset is obtained from the OpenThread Border Router.
For Matter over Wi-Fi:
```
$ chip-tool pairing ble-wifi 2 "SSID" "PSK" 20202021 3840
```

Once the commissioning process completes, enter:

$ chip-tool otasoftwareupdaterequestor announce-otaprovider 1 0 0 0 2 0

The application device will connect to the Provider and start the image download. Once the image is downloaded, the device will reboot into the downloaded image.

Note: In a production environment the Announce OTA Provider command is not used. Instead, the OTA Provider address is configured on the device by the Matter Controller, for example:

    $ chip-tool otasoftwareupdaterequestor write default-otaproviders '[{"fabricIndex": 1, "providerNodeID": 1, "endpoint": 0}]' 2 0

With this configuration the device will query the OTA-Provider for an available image every 24 hours and if an update image is available the OTA Software Update process will start.

Internal Storage Bootloader#

Internal storage bootloader for Matter OTA software update is supported on MG24/MG26 boards. In this use case, both the running image and the downloadable update image must fit on the internal flash at the same time. This in turn requires that both images are built with a reduced feature set, such as disabled logging and Matter shell. See Creating the Bootloader for Use in Matter OTA for more details.

Installing the Lower Power Mode component in the project's Software Components tool in Simplicity Studio will uninstall the following optional components and reduce the image size:

    Matter QR Code Display, 
    Matter Display, 
    Matter Shell, 
    OpenThread CLI.

Disabling logging in the configuration of the Matter Core Components component also helps to reduce the image size.

Using LZMA compression when building the .gbl file ( passing --compress lzma parameter to the commander gbl create command) further reduces the downloaded image size.

When building an internal storage bootloader, the two key configuration parameters are the Slot Start Address and Slot Size in the Bootloader Storage Slot component. The storage slot must not overlap with the running image and the NVM section of the flash. In other words, the slot start address must be greater than the end of the running image address and the sum of the start address and the slot size must be less than the address of the NVM section. The simplest way to get the relevant addresses for the running image and NVM is by using the Silicon Labs Simplicity Commander (Device Info > Main Flash > Flash Map).

The pre-built bootloader binaries are configured with slot start address of 0x080EC000 and slot size of 548864.

Managing the Software Version#

For the Provider to successfully serve the image to a device during the OTA Software Update process, the Software Version parameter that the .ota file was built with must be greater than the CHIP_DEVICE_CONFIG_DEVICE_SOFTWARE_VERSION parameter set in the application's sl_matter_config.h file which is a config file for the Matter Core Components component in the Matter Studio project. The Software Version parameter is set by the -vn parameter passed to the commander ota create command. For example, if the application's running image was built with CHIP_DEVICE_CONFIG_DEVICE_SOFTWARE_VERSION set to 1 and if the .ota file is built with -vn 2 then the Provider will serve the update image when requested.

For the OTA Software Update subsystem to consider an update to be successful and for the NotifyUpdateApplied command to be transmitted, the CHIP_DEVICE_CONFIG_DEVICE_SOFTWARE_VERSION in the updated image must exceed the software version of the running image (continuing the above example, the image for the update must be built with CHIP_DEVICE_CONFIG_DEVICE_SOFTWARE_VERSION set to 2).

The CHIP_DEVICE_CONFIG_DEVICE_SOFTWARE_VERSION is configured in a Studio Matter project by navigating to Software Components -> Silicon Labs Matter -> Stack -> Matter Core Components, clicking "Configure" and setting the "Device software version"

Managing the Vendor and Product ID#

Starting the ota-provider-app with the --otaImageList command line option allows the user to supply a JSON file specifying the Software Version, Vendor, and Product ID that identify the image served by the Provider. See the ota-provider-app for Linux in examples directory.

Example provider configuration file:

        { "foo": 1, // ignored by parser
          "deviceSoftwareVersionModel":
          [
           { 
            "vendorId": 65521, "productId": 32773, "softwareVersion": 1, "softwareVersionString": "1.0.0", "cDVersionNumber": 18, "softwareVersionValid": true, "minApplicableSoftwareVersion": 0, "maxApplicableSoftwareVersion": 100, "otaURL": "chip-efr32-lighting-example.ota" 
            }
          ]
        }

For more info see the documentation for the ota-provider-app example in https://github.com/project-chip/connectedhomeip.

Multi-Chip OTA Images#

Multi-Chip OTA is implemented only for EFR32 devices. Multi-chip OTA uses an enhanced script, ota_multi_image_tool.py, which creates .ota files that contain additional TLV headers. These TLV headers describe the binaries to be sent over the air. The enhanced script is located here. It is a wrapper to the original src/app/ota_image_tool.py. Multiple binaries can be packaged in the .ota file. Some Tags are reserved for specific Silicon Labs binaries, and other Tags are available to be used for arbitrary TLVs. The payloads can be encrypted.

The script can be obtained from the Matter Extension github repository.

For more information on creating a Multi-Chip .ota file, see the README.md.

Applications must be built with the OTA Multi Image Requestor component added to the project in Simplicity Studio to enable them to process the TLVs.

The OTA Multi Image Requestor Encryption component should be added to the project if the requestor is meant to process encrypted payloads.

Additional Info#

Developers can find more resources on the Silicon Labs Matter Community Page.