Sorry for the very basic question. I am trying to set a built-in pullup on GPIO pins and it doesn't seem to be working. Hardware is Pi 3B and 4B (I tried on both), OS is Raspbian 10 (buster). The wiringPi pin 0 (BCM pin 17) is not connected to anything:
% gpio mode 0 input % gpio mode 0 up % gpio read 0 0 %
Should this pin not be reading back a 1 due to the pull-up? What am I missing?