The "77" typically refers to a (e.g., for certain drive families). MRT itself integrates multiple tools; the Flash Tool is one of them, used to read, write, backup, and repair firmware on drives that are not detected by BIOS, have BSY errors, firmware corruption, or locked controllers .
While primarily known for MTK, the tool includes decent Qualcomm functionality. mrt hw flash tool 77
: Extensive features for flashing and FRP removal specifically for MTK variants. The "77" typically refers to a (e