Zte Zxv10: B866v2 Firmware
He dropped into the U-Boot console. This was the back alley of the device’s architecture. He needed to flash a custom image, but the stock recovery partition was checking signatures.
Sometimes necessary. If your ISP pushed a firmware that locked bridge mode or removed SSH/telnet, downgrading to an older version restores control. However, downgrading often requires a "forced" flash via the bootloader, as the web interface blocks older versions. zte zxv10 b866v2 firmware
Users generally look for two types of firmware for this device: He dropped into the U-Boot console