sim: revamp unserialization procedure

Replace direct call to unserialize() on each SimObject with a pair of
calls for better control over initialization in both ckpt and non-ckpt
cases.

If restoring from a checkpoint, loadState(ckpt) is called on each
SimObject.  The default implementation simply calls unserialize() if
there is a corresponding checkpoint section, so we get backward
compatibility for existing objects.  However, objects can override
loadState() to get other behaviors, e.g., doing other programmed
initializations after unserialize(), or complaining if no checkpoint
section is found.  (Note that the default warning for a missing
checkpoint section is now gone.)

If not restoring from a checkpoint, we call the new initState() method
on each SimObject instead.  This provides a hook for state
initializations that are only required when *not* restoring from a
checkpoint.

Given this new framework, do some cleanup of LiveProcess subclasses
and X86System, which were (in some cases) emulating initState()
behavior in startup via a local flag or (in other cases) erroneously
doing initializations in startup() that clobbered state loaded earlier
by unserialize().

1 files changed, 1 insertions, 4 deletions

diff --git a/src/sim/process.hh b/src/sim/process.hh
index e73f93fa5..3b78cb001 100644
--- a/src/sim/process.hh
+++ b/src/sim/process.hh
@@ -79,8 +79,6 @@ class Process : public SimObject
     /// running on.
     System *system;
 
-    bool checkpointRestored;
-
     // thread contexts associated with this process
     std::vector<int> contextIds;
 
@@ -130,8 +128,7 @@ class Process : public SimObject
     // constructor
     Process(ProcessParams * params);
 
-    // post initialization startup
-    virtual void startup();
+    virtual void initState();
 
   protected:
     /// Memory object for initialization (image loading)