guard stdio_uart_init_full with LIB_PICO_STDUI_UART as the function doesn't exist otherwise
@@ -127,7 +127,7 @@ void board_init(void)
#ifndef BUTTON_BOOTSEL
#endif
-#ifdef UART_DEV
+#if defined(UART_DEV) && defined(LIB_PICO_STDIO_UART)
bi_decl(bi_2pins_with_func(UART_TX_PIN, UART_TX_PIN, GPIO_FUNC_UART));
uart_inst = uart_get_instance(UART_DEV);
stdio_uart_init_full(uart_inst, CFG_BOARD_UART_BAUDRATE, UART_TX_PIN, UART_RX_PIN);
