Sony Mobile plans to make it much easier for developers to install custom ROMs. Sony will release new bootloaders for Xperia devices that will enable them to boot from the recovery partition, a key requirement to installing and booting custom ROMs.
This means that Sony Xperia users will now not have to worry whether a custom ROM even has a recovery as it will always be installed on your device. It also means users will be able to use normal recovery images used on any AOSP-based project.
Developers had to work around the limitation of not being able to boot from recovery by bundling the boot and recovery ramdisk into a single boot image. This required modifications to the Android build system that could make it difficult to recover from a bad install. The new bootloaders mean that devs no longer need to modify the build system.
The first set of Sony Xperia devices to receive the new bootloaders are those based on Cortex-A7 and include the Xperia T2 Ultra, Xperia T3, Xperia M2, and Xperia E3. These are live right now and can be installed by using Sony’s own flash tool .