Posted by Iliyan Malchev (Venture Treble Architect), Amith Dsouza (Technical Account Supervisor) , and Veerendra Bhora (Strategic Partnerships Supervisor)
Extending Android updates on Qualcomm’s Cellular Platforms
Up to now few years, the most recent Android OS has been adopted earlier by OEMs and deployed in bigger numbers to our customers. The expansion in adoption has been pushed by OEMs delivering quicker OS updates, making the most of the structure launched by Venture Treble.
On the time Android 11 launched there have been 667M lively customers on Android 10, 82% of whom received their Android 10 construct through an over the air (OTA) replace. Regardless of the occasions all through 2020, there’s a continued momentum amongst our companions to both launch their units on Android 11 or supply Android 11 OTAs on their units earlier.
Our efforts until now have been focussed on making OS updates simpler and quicker to deploy. The opposite facet of this coin is supporting updates for an extended time frame, and right this moment we’d like to offer an summary of the adjustments we’re making to assist our companions obtain this.
Project Treble was an formidable re-architecture of Android that created a cut up between the OS framework and device-specific low-level software program (referred to as the seller implementation) by a well-defined, steady vendor interface. As part of this cut up, the Android OS framework ensures backward compatibility with the seller implementation, which is checked by a standardized compliance check suite – VTS. With every Android launch, Venture Treble publishes Generic System Images (GSIs) which might be constructed from AOSP sources, and are assured to be backwards-compatible with the earlier 3 variations of vendor implementations, as well as in fact to the present launch—for a complete span of 4 years. Gadgets launching with the brand new Android launch will need to have vendor implementations suitable with that GSI. That is the first automobile for decreasing fragmentation throughout the OS framework. Whereas we permit and encourage our companions to switch the framework itself, the modifications post-Treble should be accomplished in a method that reduces improve prices from one model to the subsequent.
Moreover the reuse of a vendor implementation throughout OS updates, the Treble structure additionally facilitates the re-use of the identical OS framework code throughout completely different vendor implementations.
One other vital change launched by Venture Treble is that new vendor-impacting necessities for Android units are by no means retroactive. They apply solely to units launching on that Android model and to not units upgrading from an older model. The time period vendor-impacting right here refers to necessities for brand new HALs, or for the transport of a more moderen Linux kernel, to the machine’s vendor implementation. A great instance could be a brand new revision of the digital camera HAL to help a number of rear digital camera sensors. Because the Android framework ensures compatibility with the older HALs, we allow older vendor implementations to be reused by OEMs for upgrades with out the appreciable value of updating them with new necessities.
This precept, mixed with the backwards-compatibility assure, offers machine producers (OEMs) the flexibleness to help upgrades each quicker (since they must improve simply the framework, which might cowl all of their units, together with these with older variations of the seller implementation), in addition to at a decrease value (since they don’t have to the touch the older vendor implementations).
Nevertheless, seen from a System-on-Chip producers’ perspective, this design introduces extra complexity. For every SoC mannequin, the SoC producers now wanted to create a number of mixtures of vendor implementations to help OEMs who would use that chipset to launch new units and deploy OS upgrades on beforehand launched units.
The result’s that three years past the launch of a chipset, the SoC vendor must help as much as 6 mixtures of OS framework software program and vendor implementations. The engineering prices related to this help restricted the length for which SoC distributors supplied Android OS software program help on a chipset. For each single chipset, the software program help timeline would appear like this:
Contemplating that SoC suppliers have dozens of SoC fashions at any level of time, the total image seems nearer to this:
The crux of the issue was that, whereas machine necessities had been by no means retroactive, the necessities for SoCs had been. For instance on Android Pie, SoCs needed to help two variations of the Digicam HAL API on a chipset if it was used to help new machine launches and upgrades.
From this angle, the answer was easy: we needed to lengthen the no-retroactivity precept to the SoCs in addition to to units. With this modification, the SoC supplier would have the ability to help Android with the identical vendor implementations on their SoCs for machine launches in addition to upgrades.
Through the previous yr, we have now been working exhausting to implement this resolution. Constructing on our deep collaboration with our colleagues at Qualcomm, right this moment we’re saying the outcomes of this work. Going ahead, all new Qualcomm cellular platforms that reap the benefits of the no-retroactivity precept for SoCs will help 4 Android OS variations and 4 years of safety updates. All Qualcomm prospects will have the ability to reap the benefits of this stability to additional decrease each the prices of upgrades in addition to launches and might now help their units for longer durations of time.
Going one step additional, we’re additionally reusing the identical OS framework software program throughout a number of Qualcomm chipsets. This dramatically lowers the variety of OS framework and vendor implementation mixtures that Qualcomm has to help throughout their cellular platforms and leads to lowered engineering, improvement, and deployment prices. The diagram under signifies how vital the simplification is. From a software-support perspective, it is an altogether completely different state of affairs:
This modification is taking impact with all SoCs launching with Android 11 and later. By working carefully with Qualcomm to supply an prolonged interval of OS and safety updates, we’re wanting ahead to delivering the perfect of Android to our customers quicker, and with larger safety for an prolonged time frame.