Flash the bootloader of ATmega32U4 on openwrt

avrdude -c linuxgpio -p m32u4 -e -U lfuse:w:0xFF:m -U hfuse:w:0xD8:m -U efuse:w:0xCB:m  -U flash:w:/etc/arduino/Caterina-ReSpeaker.hex -u

Its USB virtual serial port driver is at https://github.com/Seeed-Studio/Signed_USB_Serial_Driver