I use the below command to attach to a running process to debug it. But I can't get the symbols with the command 'is' which output nothing.
r2 -a arm -b 32 -dA gdb://localhost:1234
The process is running on another device on which gdbserver is launched. I think there should be a way to let the r2 know where the bin file or so file is, but I don't know how to do that.