diff --git a/dev/etherint.hh b/dev/etherint.hh
index ddfe16d88..bcdf0ae06 100644
--- a/dev/etherint.hh
+++ b/dev/etherint.hh
@@ -31,8 +31,8 @@
  * components.
  */
 
-#ifndef __ETHERINT_HH__
-#define __ETHERINT_HH__
+#ifndef __DEV_ETHERINT_HH__
+#define __DEV_ETHERINT_HH__
 
 #include <string>
 
@@ -54,13 +54,13 @@ class EtherInt : public SimObject
     virtual ~EtherInt() {}
 
     void setPeer(EtherInt *p);
-    virtual bool recvPacket(PacketPtr &packet) = 0;
+
     void recvDone() { peer->sendDone(); }
-    bool sendPacket(PacketPtr &packet)
-    {
-        return peer ? peer->recvPacket(packet) : true;
-    }
     virtual void sendDone() = 0;
+
+    bool sendPacket(PacketPtr packet)
+    { return peer ? peer->recvPacket(packet) : true; }
+    virtual bool recvPacket(PacketPtr packet) = 0;
 };
 
-#endif // __ETHERINT_HH__
+#endif // __DEV_ETHERINT_HH__
diff --git a/dev/etherlink.cc b/dev/etherlink.cc
index ccb18d363..a361713cd 100644
--- a/dev/etherlink.cc
+++ b/dev/etherlink.cc
@@ -105,7 +105,7 @@ EtherLink::unserialize(Checkpoint *cp, const string &section)
 }
 
 void
-EtherLink::Link::txComplete(PacketPtr &packet)
+EtherLink::Link::txComplete(PacketPtr packet)
 {
     DPRINTF(Ethernet, "packet received: len=%d\n", packet->length);
     DDUMP(EthernetData, packet->data, packet->length);
@@ -122,7 +122,7 @@ class LinkDelayEvent : public Event
     LinkDelayEvent(EtherLink::Link *link);
 
   public:
-    LinkDelayEvent(EtherLink::Link *link, PacketPtr &pkt, Tick when);
+    LinkDelayEvent(EtherLink::Link *link, PacketPtr pkt, Tick when);
 
     void process();
 
@@ -153,7 +153,7 @@ EtherLink::Link::txDone()
 }
 
 bool
-EtherLink::Link::transmit(PacketPtr &pkt)
+EtherLink::Link::transmit(PacketPtr pkt)
 {
     if (busy()) {
         DPRINTF(Ethernet, "packet not sent, link busy\n");
@@ -217,7 +217,7 @@ LinkDelayEvent::LinkDelayEvent(EtherLink::Link *l)
     setFlags(AutoDelete);
 }
 
-LinkDelayEvent::LinkDelayEvent(EtherLink::Link *l, PacketPtr &p, Tick when)
+LinkDelayEvent::LinkDelayEvent(EtherLink::Link *l, PacketPtr p, Tick when)
     : Event(&mainEventQueue), link(l), packet(p)
 {
     setFlags(AutoSerialize);
diff --git a/dev/etherlink.hh b/dev/etherlink.hh
index 204348c6d..e998a006f 100644
--- a/dev/etherlink.hh
+++ b/dev/etherlink.hh
@@ -75,7 +75,7 @@ class EtherLink : public SimObject
         DoneEvent doneEvent;
 
         friend class LinkDelayEvent;
-        void txComplete(PacketPtr &packet);
+        void txComplete(PacketPtr packet);
 
       public:
         Link(const std::string &name, double rate, Tick delay,
@@ -85,7 +85,7 @@ class EtherLink : public SimObject
         virtual const std::string name() const { return objName; }
 
         bool busy() const { return (bool)packet; }
-        bool transmit(PacketPtr &packet);
+        bool transmit(PacketPtr packet);
 
         void setTxInt(Interface *i) { assert(!txint); txint = i; }
         void setRxInt(Interface *i) { assert(!rxint); rxint = i; }
@@ -104,7 +104,7 @@ class EtherLink : public SimObject
 
       public:
         Interface(const std::string &name, Link *txlink, Link *rxlink);
-        bool recvPacket(PacketPtr &packet) { return txlink->transmit(packet); }
+        bool recvPacket(PacketPtr packet) { return txlink->transmit(packet); }
         void sendDone() { peer->sendDone(); }
     };
 
diff --git a/dev/ethertap.cc b/dev/ethertap.cc
index b40a93c1b..03f2724b1 100644
--- a/dev/ethertap.cc
+++ b/dev/ethertap.cc
@@ -169,7 +169,7 @@ EtherTap::detach()
 }
 
 bool
-EtherTap::recvPacket(PacketPtr &packet)
+EtherTap::recvPacket(PacketPtr packet)
 {
     if (dump)
         dump->dump(packet);
diff --git a/dev/ethertap.hh b/dev/ethertap.hh
index 9c77a4a4f..5f760ed34 100644
--- a/dev/ethertap.hh
+++ b/dev/ethertap.hh
@@ -94,7 +94,7 @@ class EtherTap : public EtherInt
     EtherTap(const std::string &name, EtherDump *dump, int port, int bufsz);
     virtual ~EtherTap();
 
-    virtual bool recvPacket(PacketPtr &packet);
+    virtual bool recvPacket(PacketPtr packet);
     virtual void sendDone();
 
     virtual void serialize(std::ostream &os);
diff --git a/dev/ns_gige.cc b/dev/ns_gige.cc
index 8f233c433..79b128025 100644
--- a/dev/ns_gige.cc
+++ b/dev/ns_gige.cc
@@ -1979,7 +1979,7 @@ NSGigE::transferDone()
 }
 
 bool
-NSGigE::rxFilter(PacketPtr &packet)
+NSGigE::rxFilter(const PacketPtr &packet)
 {
     EthPtr eth = packet;
     bool drop = true;
@@ -2019,7 +2019,7 @@ NSGigE::rxFilter(PacketPtr &packet)
 }
 
 bool
-NSGigE::recvPacket(PacketPtr &packet)
+NSGigE::recvPacket(PacketPtr packet)
 {
     rxBytes += packet->length;
     rxPackets++;
diff --git a/dev/ns_gige.hh b/dev/ns_gige.hh
index 5f023dccc..fc2c88a6c 100644
--- a/dev/ns_gige.hh
+++ b/dev/ns_gige.hh
@@ -295,7 +295,7 @@ class NSGigE : public PciDev
      * receive address filter
      */
     bool rxFilterEnable;
-    bool rxFilter(PacketPtr &packet);
+    bool rxFilter(const PacketPtr &packet);
     bool acceptBroadcast;
     bool acceptMulticast;
     bool acceptUnicast;
@@ -360,7 +360,7 @@ class NSGigE : public PciDev
     bool cpuIntrPending() const;
     void cpuIntrAck() { cpuIntrClear(); }
 
-    bool recvPacket(PacketPtr &packet);
+    bool recvPacket(PacketPtr packet);
     void transferDone();
 
     void setInterface(NSGigEInt *i) { assert(!interface); interface = i; }
@@ -407,7 +407,7 @@ class NSGigEInt : public EtherInt
     NSGigEInt(const std::string &name, NSGigE *d)
         : EtherInt(name), dev(d) { dev->setInterface(this); }
 
-    virtual bool recvPacket(PacketPtr &pkt) { return dev->recvPacket(pkt); }
+    virtual bool recvPacket(PacketPtr pkt) { return dev->recvPacket(pkt); }
     virtual void sendDone() { dev->transferDone(); }
 };