The search for "D 39-link Dwr-m920 Firmware" appears to involve a typo or a specific mislabeled file commonly found on document-sharing sites. The correct device is the , an N300 4G LTE Router.
He disconnected the D 39-link manually. The moment the Ethernet cable left the port, the router’s little LCD screen—which had never displayed anything but “DWR-M920” for fifteen years—flashed three words: D 39-link Dwr-m920 Firmware
tftp 0x80000000 firmware.bin; bootm