Hi
Trying to deal with A10S and OSX I discover that the manufacturer of the UART0 is a company called Prolific and they have a driver for OSX.
http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=229&pcid=41 (http://www.prolific.com.tw/US/ShowProduct.aspx?p_id=229&pcid=41)
With the driver you have instructions how to install the driver and you can use the coolterm as terminal connected at 115200.
Best regards, Eduardo