Today, we released the 20.01 Azure Sphere OS for Retail Evaluation. You'll now have 14 days to verify that your applications and devices operate properly with this release. The best way to ensure that you're ready is to set up devices for OS evaluation by assigning them to a device group that receives the Retail Evaluation OS feed. We strongly encourage you to keep at least one device in such a group at all times, as a best practice.
If you encounter problems during evaluation, please notify us immediately through your Microsoft technical account manager (TAM) so that we can address any issues. Microsoft engineers and Azure Sphere community experts will also respond to product-related questions on our MSDN forum and development questions on Stack Overflow. We also welcome product feedback and new feature requests.
Update your SDK now
The existing 19.11 SDK will not work with the 20.01 OS. Attempts to use it will return Unexpected error or a similar message.
To help you verify your scenarios, we have released a 20.01 evaluation SDK that works with the 20.01 OS, for devices that receive the Retail Evaluation OS feed. You can also use the 20.01 evaluation SDK with the 19.10 and 19.11 OS releases, for devices that receive the Retail OS feed.
We strongly recommend that you upgrade to the 20.01 evaluation SDK release immediately, even if you don’t have devices that receive the Retail Evaluation OS feed. The 20.01 evaluation SDK provides more informative messages when the 20.01 OS is installed on your devices.
Features of the 20.01 evaluation SDK
The 20.01 evaluation SDK is intended to enable you to verify your applications on devices that have the new OS release. You can use it to rebuild existing applications using the sysroots and target API sets that were released with the 19.11 SDK. It does not contain the new sysroots or APIs that support new OS features; it supports only sysroots 3 and 3+Beta1909. See Important news about 20.01 retail evaluation for more information.
When the Retail Evaluation period ends, we will release the final 20.01 SDK and the documentation, so that you can develop applications that use the new features. You'll need to install the final 20.01 SDK then; the 20.01 evaluation SDK does not support all the new features of the 20.01 OS. However, we encourage you to install the 20.01 evaluation SDK in the meantime.
Recovery during the evaluation period
During the Retail Evaluation period, the online recovery images will continue to be the 19.11 OS. Because of the rollback protection in the 20.01 OS, you won't be able to use the 20.01 evaluation SDK to recover a device that has received the new OS. For the same reason, moving the device back to a group that receives the Retail OS will not restore the 19.11 OS.
If you need to recover a device that has the 20.01 OS during the Retail Evaluation period, please notify us immediately through your Microsoft technical account manager (TAM). After the Retail Evaluation period ends and the OS is available on the Retail OS feed, the online recovery images will be those for the new release, and you'll be able to recover a device if necessary.
Compatibility with existing applications
The 20.01 SDK release does not support the use of Visual Studio projects (.vcxproj and msbuild). You will need to convert any existing apps to build with CMake. See Convert a Visual Studio project to CMake for guidance.
Deploying an app that targets the 3+Beta1909 API set may result in a warning that the new OS might not support such Beta functions. The app will run successfully unless it is impacted by breaking changes in the 20.01 OS. See Upcoming Changes for a complete list of such changes. You will need to rebuild the app to target application runtime version (ARV) 4 or 4+Beta2001when the final 20.01 SDK is released after the Retail Evaluation period.
The 20.01 OS release does not include the CA certificates that were provided with preview releases. To authenticate a server with the 20.01 OS, you’ll need to update the application image package to include the required certificate. For details, see Server authentication.