> I tried unplugging the cable from the target completely and running again, > and got the same error.
That makes sense since TDO on the Olimex will most likely be pulled or floating high by default so it'll be read as 1 when disconnected. The fact that it's reading high when connected is the issue. As I mentioned before, maybe the connector is not orientated properly (at both ends - Olimex and board connector). If it is then the issue may be board related. Either there's some jumper or other configuration needed for the debug connection to work, the debug block is locked from access on some way, the board is faulty, etc.
