Prepare an OTA image

OTA firmware update images must conform to the Matter OTA Software Image file format, which includes:

• A file identifier that uniquely identifies the file as being a Matter firmware update file
• The size of the file
• The header size
• A Tag-length-value (TLV)-encoded header containing information about the update, including:
  • VID
  • PID
  • software version
• The payload

The Matter SDK provides a tool to create and inspect Matter OTA images (ota_image_tool.py). Some build systems can create Matter OTA images automatically, so check your SoC documentation.

Create an OTA image

Use ota_image_tool.py to create the image:

$ ./ota_image_tool.py create \
  -v hexVendorId \
  -p hexProductId \
  -vn versionNumber \
  -vs "versionString" \
  -da "hash-function \
  path_to_binary \
  path_to_ota_file

To verify the metadata set and the header of the file, run the script with the show command:

$ ./ota_image_tool.py show path_to_ota_file

Example output:

Magic: 1beef11e
Total Size: 90
Header Size: 62
Header TLV:
  [0] Vendor Id: XXXX (0xXX)
  [1] Product Id: XXX (0xXX)
  [2] Version: 101 (0x65)
  [3] Version String: 1.0.1
  [4] Payload Size: 12 (0xc)
  [8] Digest Type: 1 (0x1)
  [9] Digest: a948904f2f0f429b8f8197694b30184b0d2ed1c3cd2a1ec0fb85d299a193a447

Upload the OTA image

To upload the image to the Google Home Developer Console:

Go to the Developer Console

1. Go to Matter > OTA.

2. Click Manage next to the device in the Devices list.

3. In the OTA Configuration page, click the Images tab.

4. Click New Image.

1. Give the image a name and click Attach Image to select and upload the image file.

2. Once the image is successfully validated, click Save.

3. When the confirmation dialog appears, click Save to make the image available to your devices, or click Cancel to cancel the submission.

The OTA image is available for distribution shortly after uploading.