Xyauto 9212b Firmware Update ✓

✅ I have confirmed my MCU version and resolution. ✅ I have downloaded firmware that matches both. ✅ I have backed up any irreplaceable data. ✅ I have a FAT32 USB drive ready. ✅ I have stable power to the head unit. ✅ I know how to enter recovery mode if needed. ✅ I am prepared to reconfigure CAN bus and Bluetooth after update.