Sony have confirmed today that recovery mode is now available for a number of unlocked Sony Xperia devices thanks to their "open device" program, which is designed to provide a developer environment close to that of Google's Nexus devices. Until now, recovery mode was simply unavailable for many Xperia smartphones, whereas other manufacturers included the mode in their firmware. Sony have reported that the recovery mode is a runtime environment included on a hardware partition separate from the main Android operating system. Recovery mode, for the uninitiated, is a feature designed to help customers resolve issues with devices and it's triggered by a reboot with various hardware keys held down. It's typically used for troubleshooting or as part of the process of replacing the stock software with a custom ROM or kernel. Karl-Johan Dahlstr¶m, Head of Developer Relations, said this on the matter: "Our overall goal with the open device program is to offer a development environment similar to the one for Nexus devices. Now, by making it much easier to debug, we hope this will further encourage innovation and kernel development on Xperia devices." In other words, Sony are hoping to encourage development for Xperia devices by releasing the recovery mode.
After flashing a recovery image to the Xperia device, customers can use recovery mode to flash custom ROMs, run over-the-air updates, maintenance or restore back up data. Providing there's a stable recovery kernel, Sony would encourage developers to try out, innovate and potentially unstable kernel versions. Should the experimental kernel be unreliable, developers may revert back to the stable kernel.
The recovery mode has been enabled for the Xperia Z1, Xperia Z1 Compact, Xperia Z Ultra, Xperia E3, Xperia M2, Xperia T2 Ultra, and Xperia T3 devices with unlocked boot loader via the latest software pushed onto the device via the Sony Flash tool. Once you have the latest software installed on the device the solution is to power the device off, then power on with the volume down key depressed until the device vibrates. As it vibrates, release the power key but keep the volume down button depressed. After a brief pause, the device will boot into recovery mode and you control this using the volume keys (for up and down) and the power button (to select).
This is a welcome development from Sony although there are many in the development community that will sigh it's about time. Sony have been long time supporters of the AOSP (Android Open Source Project) and have purported to support developers, although sometimes their efforts have been circumvented by carriers locking down the devices. Sony also released a Google Play Edition version of the Sony Xperia Z Ultra but despite rumors on and off, have not released a Nexus device. The current rumors are not suggesting we'll see a Sony Nexus any time soon. Still, Sony write that they are excited to be (finally) offering the development community the recovery mode and have plans to include more unlocked models in the coming months are they update the software. You can check the video below for further information.