AWS IoT Over-the-air Update Library
The OTA library enables you to manage the notification of a newly available update, download the update, and perform cryptographic verification of the firmware update. Using the library, you can logically separate firmware updates from the application running on your devices. The OTA library can share a network connection with the application, saving memory in resource-constrained devices. In addition, the OTA library lets you define application-specific logic for testing, committing, or rolling back a firmware update. The library supports different application protocols like Message Queuing Telemetry Transport (MQTT) and Hypertext Transfer Protocol (HTTP), and provides various configuration options you can fine tune depending on network type and conditions. This library is distributed under the MIT Open Source License.
This library has gone through code quality checks including verification that no function has a GNU Complexity score over 8. This library has also undergone static code analysis from Coverity static analysis.
See memory requirements for this library here.
AWS IoT Over-the-air Update Library v3.4.0 source code is part of the FreeRTOS 202210.00 LTS release.
AWS IoT Over-the-air Update Library v3.3.0 source code is part of the FreeRTOS 202012.01 LTS release.
AWS IoT Over-the-air Updates Config File
The AWS IoT Over-the-air Updates library exposes configuration macros that are required for building the library. A list of all the configurations and their default values are defined in ota_config_defaults.h. To provide custom values for the configuration macros, a custom config file named ota_config.h
can be provided by the user application to the library.
By default, a ota_config.h
custom config is required to build the library. To disable this requirement and build the library with default configuration values, provide OTA_DO_NOT_USE_CUSTOM_CONFIG
as a compile time preprocessor macro.
Building the Library
The otaFilePaths.cmake file contains the information of all source files and the header include paths required to build the AWS IoT Over-the-air Updates library.
As mentioned in the previous section, either a custom config file (i.e. ota_config.h
) OR the OTA_DO_NOT_USE_CUSTOM_CONFIG
macro needs to be provided to build the AWS IoT Over-the-air Updates library.
For a CMake example of building the AWS IoT Over-the-air Updates library with the otaFilePaths.cmake
file, refer to the coverity_analysis
library target in the test/CMakeLists.txt file.
Building Unit Tests
Checkout CMock Submodule
By default, the submodules in this repository are configured with update=none
in .gitmodules to avoid increasing clone time and disk space usage of other repositories (like AWS IoT Device SDK for Embedded C that submodules this repository).
To build unit tests, the submodule dependency of CMock is required. Use the following command to clone the submodule:
git submodule update --checkout --init --recursive test/unit-test/CMock
Platform Prerequisites
For building the library, CMake 3.13.0 or later and a C90 compiler.
For running unit tests, Ruby 2.0.0 or later is additionally required for the CMock test framework (that we use).
For running the coverage target, gcov and lcov are additionally required.
Steps to build unit tests
Go to the root directory of this repository. (Make sure that the CMock submodule is cloned as described above.)
Run the cmake command:
cmake -S test -B build
Run this command to build the library and unit tests:
make -C build all
The generated test executables will be present in
build/bin/tests
folder.Run
cd build && ctest
to execute all tests and view the test run summary.
Migration Guide
How to migrate from v2.0.0 (Release Candidate) to v3.4.0
The following table lists equivalent API function signatures in v2.0.0 (Release Candidate) and v3.4.0 declared in ota.h
v2.0.0 (Release Candidate) |
v3.4.0 |
Notes |
---|---|---|
|
|
|
How to migrate from version 1.0.0 to version 3.4.0 for OTA applications
Refer to OTA Migration document for the summary of updates to the API. Migration document for OTA PAL also provides a summary of updates required for upgrading the OTA-PAL to work with v3.4.0 of the library.
Porting
In order to support AWS IoT Over-the-air Updates on your device, it is necessary to provide the following components:
For enabling data transfer over HTTP dataplane the following component should also be provided:
NOTE When using OTA over HTTP dataplane, MQTT is required for control plane operations and should also be provided.
CBMC
To learn more about CBMC and proofs specifically, review the training material here.
The test/cbmc/proofs
directory contains CBMC proofs.
In order to run these proofs you will need to install CBMC and other tools by following the instructions here.
Reference examples
Please refer to the demos of the AWS IoT Over-the-air Updates library in the following location for reference examples on POSIX and FreeRTOS:
Platform |
Location |
---|---|
POSIX |
|
FreeRTOS |
|
FreeRTOS |
Documentation
Existing Documentation
For pre-generated documentation, please see the documentation linked in the locations below:
Location |
---|
Note that the latest included version of coreMQTT may differ across repositories.
Generating documentation
The Doxygen references were created using Doxygen version 1.9.2. To generate the Doxygen pages, please run the following command from the root of this repository:
doxygen docs/doxygen/config.doxyfile
Contributing
See CONTRIBUTING.md for information on contributing.