Sony Xperia devices use a secure boot chain anchored in hardware. The is the first code executed on the device’s Qualcomm or MediaTek chipset. It verifies the digital signature of the subsequent bootloader. If the signature is invalid, the device hard-bricks (becomes irrecoverable).
The S1 unlock tool supports a wide range of Sony Xperia devices, from the old Xperia Z series to modern Xperia 1, 5, and 10 series. However, compatibility changes with each tool version. Below is a general list of confirmed models (as of the latest S1 Tool v7.x): s1 unlock tool sony
Permanently removes carrier locks, even if the "SIM lock" counter is at zero. Bootloader Status Modification: Sony Xperia devices use a secure boot chain
In the US, unlocking a phone without carrier permission is banned under the DMCA for devices purchased after 2013 (though the law has exceptions for personal use). In the EU, network unlocking is allowed after contract end. Always check your local laws. If the signature is invalid, the device hard-bricks