When using "pipe", also use log_output to redirect the log
output to a file so as not to flood the stdin/out pipes.
-The -p/--pipe option is deprecated and a warning is printed
-as it is equivalent to passing in -c "gdb_port pipe; log_output openocd.log".
-
Any other string is interpreted as named pipe to listen to.
Output pipe is the same name as input pipe, but with 'o' appended,
e.g. /var/gdb, /var/gdbo.