29 August 2018
Sony recently released its official list of Xperia devices which will be upgraded to Android 9 Pie. The list further mentioned an estimated timeline for the rollout where the Xperia XZ2 and Xperia XZ1 series devices are first in the line. As for the XA2, XA2 Ultra, and XA2 Plus devices, the upgrade is expected to arrive sometime during early 2019.
If you are wondering why there is such a big difference in the rollout of the update for these devices, Sony has also shared an infographic detailing the whole process. There is no doubt that the software upgrade process is a lengthy one filled with various complicated steps but this infographic offers a simplistic overview of the same.
Everything starts with Google sending a Platform Development Kit (PDK) few weeks ahead of the new Android version. This kit comprises of source code and other necessary tools which allow Sony to start development, optimization, and testing. Once Google makes the Android version official, the team starts working on Hardware Abstraction Layer (HAL) which is basically making sure that different chips work perfectly with the new version. While this is usually handled by chipmakers, Sony has to do this on its own because it does not use the same components as Qualcomm.
The next couple of steps include working on basic functionalities like calling, texting, and internet connectivity along with Sony-specific ones. It is followed by testing the new version while also applying for mandatory certification approvals like Bluetooth and WiFi. It also has to work with operators (carriers) to make sure that the new version works according to their needs and requirements. Once all these steps are done, the new Android version is rolled out for public use.
While all of this is quite true, it is not an excuse for OEMs to offer slow upgrades and even choosing to ignore certain devices. This also explains why stock Android versions are usually the faster ones to receive updates.