Thanks mhahn. Grub commands don't seem to match uboot. I tried lots of variations including 'single' as well as 'run bootcmd single' and various forms of -s, s, single, 1, and -1). None of them worked. Based on response from JPMonteiro there doesn't appear to be a way to go single-user. Ended up reflashing and starting all over.
Really wish they'd add that in. It's going to be a big barrier in the way of adding startup services to systemd.