1 files changed, 44 insertions, 0 deletions
diff --git a/os/nil/src/nil.c b/os/nil/src/nil.c
index 9254acbc0..7d3dab9ce 100644
--- a/os/nil/src/nil.c
+++ b/os/nil/src/nil.c
@@ -306,6 +306,50 @@ void chSysRestoreStatusX(syssts_t sts) {
   }
 }
 
+#if (PORT_SUPPORTS_RT == TRUE) || defined(__DOXYGEN__)
+/**
+ * @brief   Realtime window test.
+ * @details This function verifies if the current realtime counter value
+ *          lies within the specified range or not. The test takes care
+ *          of the realtime counter wrapping to zero on overflow.
+ * @note    When start==end then the function returns always true because the
+ *          whole time range is specified.
+ * @note    This function is only available if the port layer supports the
+ *          option @p PORT_SUPPORTS_RT.
+ *
+ * @param[in] cnt       the counter value to be tested
+ * @param[in] start     the start of the time window (inclusive)
+ * @param[in] end       the end of the time window (non inclusive)
+ * @retval true         current time within the specified time window.
+ * @retval false        current time not within the specified time window.
+ *
+ * @xclass
+ */
+bool chSysIsCounterWithinX(rtcnt_t cnt, rtcnt_t start, rtcnt_t end) {
+
+  return (bool)((cnt - start) < (end - start));
+}
+
+/**
+ * @brief   Polled delay.
+ * @note    The real delay is always few cycles in excess of the specified
+ *          value.
+ * @note    This function is only available if the port layer supports the
+ *          option @p PORT_SUPPORTS_RT.
+ *
+ * @param[in] cycles    number of cycles
+ *
+ * @xclass
+ */
+void chSysPolledDelayX(rtcnt_t cycles) {
+  rtcnt_t start = chSysGetRealtimeCounterX();
+  rtcnt_t end  = start + cycles;
+
+  while (chSysIsCounterWithinX(chSysGetRealtimeCounterX(), start, end)) {
+  }
+}
+#endif /* PORT_SUPPORTS_RT == TRUE */
+
 /**
  * @brief   Makes the specified thread ready for execution.
  *