Major OEM Sony's mid-range camera monsters, the Xperia XA1, Xperia XA1 Ultra, and Xperia XA1 Plus, have reportedly begun receiving their updates to Android 8.0 Oreo, along with the February 5, 2018 Android Security Bulletin. Users are seeing their build numbers bumped up to 48.1.A.0.116 from the 48.0.A.1.131 build number representing the phone family's build of Android 7.0 Nougat. The updates are rolling out gradually over the air, and should weigh in somewhere around 883MB for most users. As of this writing, manually flashable FTF firmware files for these updates are unavailable, leaving Xperia XA1 series owners to wait for the updates to be pushed to them.
For those unfamiliar with Sony's take on Android, it's rather minimalist, with a few software tweaks here and there, with PlayStation integration and great cameras being two of the biggest selling points for Sony devices. An Oreo update for a Sony device brings along all of the normal Google goodness, and some new Sony features like intelligent Xperia actions that pop up on a contextual basis by analyzing what you're doing at the moment, and reminders to do things like finish up draft emails or return missed calls. Visually, the update keeps the same kind of low profile seen in previous Sony updates; that is to say, Sony's own font and a few color accents are on board, along with some custom icons for the launcher. For the most part, your device will look and behave like a phone running stock Android, such as a Pixel or Android One device.
As with any update major or minor, there are some caveats. If flashing the update manually, take care not to let the phone and the computer lose connection during flashing. For that matter, no matter how you're taking the update, avoid letting the phone power down or have the update stop once it's begun installing; doing so could result in a hardbrick, rendering your phone completely unusable. Ensure you've got adequate disk space to store the update files and some extra space for decompressing and unpacking temporary files; normally, about twice the size of the update file should be enough. It is wise to take the update with your phone plugged into a power source, but if you must take it on the go, make sure that you're using a battery that is in good condition and has at least 50-percent charge left.