We present a lightweight Southbound Interface (SBI) for P4→NetFPGA devices, aimed at enhancing the capability of NetFPGA Smart Network Interface Cards (SmartNICs) to work in standalone mode. We propose a custom protocol allowing the control plane to remotely populate the board's routing tables and query runtime information. We achieve this thanks to the implementation of a lookup table (LUT) extern function that can be directly edited by the P4 program-a feature notably lacking in the context of P4→NetFPGA.