I loaded the b143 image to memory address 0xBC050000 instead and then was able to boot it from u boot but I got the same fatal exception and reboot which was confusing.
However, then I tried flashing from USB again and it worked this time so now I'm up and running. Not sure exactly how that worked but learned a bit about u boot.
Edit: Am now able to connect to wifi without issue as well. This is resolved.