Google introduced Project Treble back in 2017 to combat the problem of OS fragmentation and streamline the process of Android updates. The firm boasted of the gains in the speed of adoption of Android 10 earlier this year, stating that that version of the OS saw the fastest pace of adoption, ever.
Project Treble helped speed up the process of OS updates by creating a “system/vendor” split that let OEMs and SoC develop devices and silicon independent of each other. These modules communicate through the form of a stable vendor interface. When new versions of the OS are released, Google releases Generic System Images (GSIs) that are compatible with the previous three vendor interfaces and implementations (low-level, device specific software). The firm also mandates that OEMs that release new devices with the new OS make their implementation compatible with the GSIs, thus making them compatible with older interfaces, even if OEMs modify the OS framework to their liking.
Another advantage with Treble was that new vendor-impacting requirements did not apply to older implementations, meaning that when new hardware level features – such as support for multiple cameras – or kernel-level changes were made to the OS, those applied only to new devices on the new versions of the OS. This allowed OEMs to re-use the old implementation for upgrading older devices, reducing the cost of development to update the entire vendor interface for older devices while maintaining compatibility with the GSIs.
However, this meant that chipmakers such as Qualcomm had to support multiple OS frameworks and vendor interfaces. For example, the SoC manufacturer had to support the implementation for both the old interface and the one with new hardware features – like multiple camera support. Therefore, chipsets had to support at least six implementations for three generations of the OS, limiting OEMs and vendors from supporting older devices for longer due to increased development costs.
To remedy this, Google is detailing its work with Qualcomm in bringing a “no-retroactivity principle to SoCs and devices”. This allows for new SoCs from Qualcomm to support the “same vendor implementations on their SoCs for device launches as well as upgrades”, the firm says. This means that newer chips – say on Android 11 – can re-use the implementation for further releases without having to retroactively support new additions made to the frameworks, helping reduce costs for vendors and OEMs. Additionally, Google also promises to reuse the same OS framework across chipsets, to further reduce costs.
These changes to Project Treble will help OEMs and chip makers support up to four Android OS versions and four years of security updates, Google says, adding that the said changes will be made to chipsets such as the Snapdragon 888 launching with Android 11, and newer.
While the changes technically allow for easier OS updates for up to four years, it also involves the investment of OEMs to opt into supporting its devices. While companies like Samsung have promised at least three OS updates for its devices, it will be interesting to see if Android OEMs extend support for its devices by leveraging the advantages brought by the changes to Project Treble, along with other components such as Project Mainline.