diff --git a/esp8266/esp_mphal.c b/esp8266/esp_mphal.c
index 3681a02..c8a88c7 100644
--- a/esp8266/esp_mphal.c
+++ b/esp8266/esp_mphal.c
@@ -39,6 +39,8 @@
 extern void wdt_feed(void);
 extern void ets_delay_us();
 
+STATIC byte input_buf_array[256];
+ringbuf_t input_buf = {input_buf_array, sizeof(input_buf_array)};
 void mp_hal_debug_tx_strn_cooked(void *env, const char *str, uint32_t len);
 const mp_print_t mp_debug_print = {NULL, mp_hal_debug_tx_strn_cooked};
 
@@ -151,3 +153,7 @@
     nlr_raise(mp_obj_new_exception_msg(&mp_type_AssertionError,
         "C-level assert"));
 }
+
+void mp_hal_signal_input(void) {
+    system_os_post(UART_TASK_ID, 0, 0);
+}