icE1USB gateware

Dear list, I built an icE1USB device so I can provide stable clock to my legacy Nokia BTS. I have not found any information about how to bring up a completely empty device, so I just took the icE1usb-202210-5890f3e4.bin file and flashed it to the SPI flash, yet the device is not booting. Maybe something else is missing (like a boot block), or the binary has to be flashed with an offset? The device takes 80mA in this state, USB device is not recognized on the host. Thanks!