NXP OTA image tool#

Overview#

This tool can generate an OTA image in the |OTA standard header|TLV1|...|TLVn| format. The payload contains data in standard TLV format (not Matter TLV format). During OTA transfer, these TLV can span across multiple BDX blocks, thus the OTAImageProcessorImpl instance should take this into account.

For details related to the OTA implementation, please see OTA README.

Supported platforms#

  • k32w0

  • k32w1

  • mcxw71

Usage#

This is a wrapper over standard ota_image_tool.py, so the options for create are also available here:

python3 ./scripts/tools/nxp/ota/ota_image_tool.py create -v 0xDEAD -p 0xBEEF -vn 50000 -vs "1.0" -da sha256

followed by custom options- and a positional argument (should be last) that specifies the output file. Please see the create_ota_images.sh for some reference commands.

The list of custom options:

option

description

--app-input-file

Path to the application binary

--app-version

Application version. Can differ from -vn

--app-version-str

Application version string. Same as above

--app-build-date

Application build date. Same as above

--bl-input-file

Path to the SSBL binary

--bl-version

SSBL version

--bl-version-str

SSBL version string

--bl-build-date

SSBL build date

--factory-data

Enable the generation of factory data

--cert_declaration

Matter Certification Declaration

--dac_cert

Matter DAC certificate

--dac_key

Matter DAC private key

--pai_cert

Matter PAI certificate

--json

Path to a JSON file following ota_payload.schema

Please note that the options above are separated into four categories: application, bootloader, factory data and custom TLV (--json option). If no descriptor options are specified for app/SSBL, the script will use the default values (50000, "50000-default", "2023-01-01"). The descriptor feature is optional, TLV processors having the option to register a callback for descriptor processing.

Custom payload#

When defining a custom processor, a user is able to also specify the custom format of the TLV by creating a JSON file based on the ota_payload.schema. The tool offers support for describing multiple TLV in the same JSON file. Please see the examples/ota_max_entries_example.json for a multi-app + SSBL example. Option --json must be used to specify the path to the JSON file.

Examples#

A set of examples can be found in ./examples. Please run create_ota_image.sh to generate the examples:

  • Application image with default descriptor

  • Application image with specified descriptor

  • Factory data image

  • SSBL image

  • Application + SSBL + factory data image

  • Maximum number of entries image, using ota_max_entries_example.json. The examples uses 8 SSBL binaries because they have a small size and fit in external flash.

The binaries from ./examples/binaries should only be used only as an example. The user should provide their own binaries when generating the OTA image.