Flash fastboot firmware from internal memory
Hi, i have xt1641 channel retmx, i trying to update to oreo official firmware but its not released to my country, i am facing my phone doesnt connect to fastboot, i have installed drivers correctly, i flashed some other moto devices, so i think the usb connector of the phone is damaged, also, if i connect it to the computer when its powered on, it just charge but not detecting usb connection, thats why i am trinyng to flash a fastboot firmware from internal memory, does it possible? i have tried just downloading the firmware but it fails because signature verification, is there a way to toogle signature verification?
i also tried with ota update file but it doesnt allowed me to flash because its expecting a newer firmware than its already has.
Thanks inadvance
UPDATE: i have been testing, i am on linux, i connected another phone to the same pc, same usb port, using same usb cable andeverythig works, the broken phone detecs the connection when its in fastboot mode, mut the computer doesnt detect nothing, i went with my wife to try on windows and thecomputer detected the phone but doesnt recognized it even on fasboot mode or into android.
please help, i need to update this device because im stucked on android 7 stock rom with stock recovery, if i could flash twrp from stock would be great, but i just need te be on oreo, i dont care if its stock rom. thanks again