diff -r 5a6edc799552 -r 614c211270b3 src/mem/packet.hh
--- a/src/mem/packet.hh	Tue Jan 11 08:18:21 2011 -0800
+++ b/src/mem/packet.hh	Tue Jan 11 09:29:48 2011 -0800
@@ -681,9 +681,9 @@
      */
     template <typename T>
     T*
-    getPtr()
+    getPtr(bool null_ok = false)
     {
-        assert(flags.isSet(STATIC_DATA|DYNAMIC_DATA));
+        assert(null_ok || flags.isSet(STATIC_DATA|DYNAMIC_DATA));
         return (T*)data;
     }
 
@@ -768,7 +768,6 @@
         data = new uint8_t[getSize()];
     }
 
-
     /**
      * Check a functional request against a memory value represented
      * by a base/size pair and an associated data array.  If the
diff -r 5a6edc799552 -r 614c211270b3 src/mem/ruby/system/DMASequencer.cc
--- a/src/mem/ruby/system/DMASequencer.cc	Tue Jan 11 08:18:21 2011 -0800
+++ b/src/mem/ruby/system/DMASequencer.cc	Tue Jan 11 09:29:48 2011 -0800
@@ -97,8 +97,10 @@
     msg->getLen() = (offset + len) <= RubySystem::getBlockSizeBytes() ?
         len : RubySystem::getBlockSizeBytes() - offset;
 
-    if (write) {
-        msg->getDataBlk().setData(data, offset, msg->getLen());
+    if (write && (data != NULL)) {
+        if (active_request.data != NULL) {
+            msg->getDataBlk().setData(data, offset, msg->getLen());
+        }
     }
 
     assert(m_mandatory_q_ptr != NULL);
@@ -160,8 +162,10 @@
     if (active_request.bytes_completed == 0)
         offset = active_request.start_paddr & m_data_block_mask;
     assert(active_request.write == false);
-    memcpy(&active_request.data[active_request.bytes_completed],
-           dblk.getData(offset, len), len);
+    if (active_request.data != NULL) {
+        memcpy(&active_request.data[active_request.bytes_completed],
+               dblk.getData(offset, len), len);
+    }
     issueNext();
 }
 
diff -r 5a6edc799552 -r 614c211270b3 src/mem/ruby/system/RubyPort.cc
--- a/src/mem/ruby/system/RubyPort.cc	Tue Jan 11 08:18:21 2011 -0800
+++ b/src/mem/ruby/system/RubyPort.cc	Tue Jan 11 09:29:48 2011 -0800
@@ -245,7 +245,7 @@
         }
     }
 
-    RubyRequest ruby_request(pkt->getAddr(), pkt->getPtr<uint8_t>(),
+    RubyRequest ruby_request(pkt->getAddr(), pkt->getPtr<uint8_t>(true),
                              pkt->getSize(), pc, type,
                              RubyAccessMode_Supervisor, pkt);