How to implement printf in RZ/T1 e2studio&KPITGCC

Hi,

       I have reference Async_serial sample code of application note.

       https://www.renesas.com/zh-tw/software/D3017415.html

       and try to implement Async_serial in new project by code generator.

       But I didn't know how to implement printf function.

       Is there document or information about implement printf function in RZ/T1 ?