I have tried to use a FreeBSD-13.0-RELEASE memory card image on my RPI2B but I get the dreaded rainbow screen. (Also tried 13.1-RC6 same result)
I have use the following command to create the memory card;
dd if=FreeBSD-13.0-arm-armv6-RPI-B.img of=/dev/da0 bs=1m conv=sync
The image writes without issue but when placed in the RPI2B it will not boot.
The two file systems are moutable using a memory card reader and plugging that into another FreeBSD machine;
mount -t msdosfs /dev/da0s1 /msdos
mount /dev/da0s2a /mnt
I have also tried FreeBSD-12.3-RELEASE image using the same dd command and the RPI2B boots just fine. i.e. works as intended.
The power supply is a good quality one with an output of 3.1 amps.
RPI-B is only for the first revision of the Pi and the Pi0.
For RPI2 use FreeBSD-13.0-RELEASE-arm-armv7-GENERICSD.img.
Thanks Emmanuel. I was just in the process I trying this.