devices: Fixed periodic interrupts to work with draining

Added drain functions to the RTC and 8254 timer so that periodic interrupts
stop when the system is draining.  This patch is needed to checkpoint in
timing mode.  Otherwise under certain situations, the event queue will never
be completely empty.

1 files changed, 6 insertions, 0 deletions

diff --git a/src/dev/mc146818.hh b/src/dev/mc146818.hh
index 699785199..507abab5a 100644
--- a/src/dev/mc146818.hh
+++ b/src/dev/mc146818.hh
@@ -119,6 +119,10 @@ class MC146818 : public EventManager
     /** RTC status register B */
     uint8_t stat_regB;
 
+    /** RTC event times for drain and serialization coordination */
+    Tick rtcTimerInterruptTickOffset;
+    Tick rtcClockTickOffset;
+
   public:
     MC146818(EventManager *em, const std::string &name, const struct tm time,
             bool bcd, Tick frequency);
@@ -132,6 +136,8 @@ class MC146818 : public EventManager
 
     void tickClock();
 
+    unsigned int drain(Event *de);
+
     /**
       * Serialize this object to the given output stream.
       * @param base The base name of the counter object.