Hi. I've took an image FreeBSD-12.0-RELEASE-arm-armv6-RPI-B.img, wrote it on microSD with dd(1) and tried to boot on my Raspberry Pi 3 B+. Green LED blinks shortly and I see only rainbow screen on my HDMI display and it stuck. And I see no data on UART interface. What's problem? How to debug? Give me a hint please.