On specific Sony platforms (Yoshino and Tama chipsets), a Fastboot USB interface vulnerability (CVE-2021-1931) allows bootloader unlocking even when allowed shows "NO." This exploit works on Xperia XZ1, XZ1 Compact, XZ2, and XZ2 Compact models, which use Snapdragon 835 or 845 processors. The exploit works by exploiting a buffer overflow vulnerability in the Fastboot interface, bypassing all official restrictions. However, even after unlocking via this exploit, DRM features will not work with an unlocked bootloader state, though the device key is not erased from TA as it would be with official unlocking. It is essential to backup TA even when using this exploit.
Bootloader unlocking exists in a legal gray area in some jurisdictions. While modifying your own device is generally legal, some manufacturers have included clauses in their legal agreements that prohibit reselling devices after unlocking the bootloader, raising concerns about ownership rights. If you purchased your Docomo device through a carrier contract, unlocking may violate your service agreement.
Unlocking the bootloader triggers a mandatory factory reset. Back up all data before proceeding. docomo unlock bootloader install
Magisk is the modern standard for systemless root:
Unlocking the bootloader, especially on a carrier-locked Docomo device, comes with significant risks that must be acknowledged. On specific Sony platforms (Yoshino and Tama chipsets),
Select Reboot System . The first boot can take up to 5–10 minutes. 7. Crucial Post-Installation Pitfalls for Japanese Devices
From TWRP recovery, select "Install" and navigate to the Magisk zip file It is essential to backup TA even when using this exploit
DOCOMO will allow you to SIM‑unlock your phone after certain conditions are met (contract duration, fee payment), but they . In fact, attempting these modifications will void any remaining warranty.
Always make a of your device before starting, and proceed at your own risk. The information in this article is provided for educational purposes only; the author and sources are not responsible for any damage to your device.
Tap seven times until a toast notification reads "You are now a developer." Go back to Settings > System > Developer Options . Enable USB Debugging .