Sony Xperia Phone - Service / Test Menu - iFixit Repair Guide
Sony devices use a proprietary "Flash Mode" (accessed by holding Volume Down while plugging in USB) and "Fastboot Mode." QunlockTool exploits these low-level environments to modify the partition table (GPT) and the TA partition, which contains the "Trim Area" data—where DRM keys, Bootloader status, and Lock status are stored. qunlocktool sony