diff -r 9934883ab246 -r b2c1502e2508 configs/example/se.py
--- a/configs/example/se.py	Sat Feb 23 00:40:44 2013 -0600
+++ b/configs/example/se.py	Sat Feb 23 00:40:54 2013 -0600
@@ -187,6 +187,9 @@
         print >> sys.stderr, "Ruby requires TimingSimpleCPU or O3CPU!!"
         sys.exit(1)
 
+    # Set the option for physmem so that it is not allocated any space
+    system.physmem.null = True
+
     options.use_map = True
     Ruby.create_system(options, system)
     assert(options.num_cpus == len(system.ruby._cpu_ruby_ports))
diff -r 9934883ab246 -r b2c1502e2508 src/mem/ruby/system/Sequencer.py
--- a/src/mem/ruby/system/Sequencer.py	Sat Feb 23 00:40:44 2013 -0600
+++ b/src/mem/ruby/system/Sequencer.py	Sat Feb 23 00:40:54 2013 -0600
@@ -41,7 +41,7 @@
     pio_port = MasterPort("Ruby_pio_port")
     using_ruby_tester = Param.Bool(False, "")
     using_network_tester = Param.Bool(False, "")
-    access_phys_mem = Param.Bool(True,
+    access_phys_mem = Param.Bool(False,
         "should the rubyport atomically update phys_mem")
     ruby_system = Param.RubySystem("")
     system = Param.System(Parent.any, "system object")
@@ -52,6 +52,7 @@
 class RubyPortProxy(RubyPort):
     type = 'RubyPortProxy'
     cxx_header = "mem/ruby/system/RubyPortProxy.hh"
+    access_phys_mem = True
     
 class RubySequencer(RubyPort):
     type = 'RubySequencer'
@@ -67,3 +68,4 @@
 class DMASequencer(RubyPort):
     type = 'DMASequencer'
     cxx_header = "mem/ruby/system/DMASequencer.hh"
+    access_phys_mem = True
diff -r 9934883ab246 -r b2c1502e2508 tests/configs/memtest-ruby.py
--- a/tests/configs/memtest-ruby.py	Sat Feb 23 00:40:44 2013 -0600
+++ b/tests/configs/memtest-ruby.py	Sat Feb 23 00:40:54 2013 -0600
@@ -79,8 +79,8 @@
 # system simulated
 system = System(cpu = cpus,
                 funcmem = SimpleMemory(in_addr_map = False),
-                funcbus = NoncoherentBus(),
-                physmem = SimpleMemory())
+                physmem = SimpleMemory(null = True),
+                funcbus = NoncoherentBus())
 
 Ruby.create_system(options, system)
 
@@ -100,12 +100,6 @@
      #
      ruby_port.deadlock_threshold = 1000000
 
-     #
-     # Ruby doesn't need the backing image of memory when running with
-     # the tester.
-     #
-     ruby_port.access_phys_mem = False
-
 # connect reference memory to funcbus
 system.funcmem.port = system.funcbus.master
 
diff -r 9934883ab246 -r b2c1502e2508 tests/configs/pc-simple-timing-ruby.py
--- a/tests/configs/pc-simple-timing-ruby.py	Sat Feb 23 00:40:44 2013 -0600
+++ b/tests/configs/pc-simple-timing-ruby.py	Sat Feb 23 00:40:54 2013 -0600
@@ -74,5 +74,8 @@
     cpu.interrupts.int_slave = system.piobus.master
     cpu.clock = '2GHz'
 
+    # Set access_phys_mem to True for ruby port
+    system.ruby._cpu_ruby_ports[i].access_phys_mem = True
+
 root = Root(full_system = True, system = system)
 m5.ticks.setGlobalFrequency('1THz')
diff -r 9934883ab246 -r b2c1502e2508 tests/configs/rubytest-ruby.py
--- a/tests/configs/rubytest-ruby.py	Sat Feb 23 00:40:44 2013 -0600
+++ b/tests/configs/rubytest-ruby.py	Sat Feb 23 00:40:54 2013 -0600
@@ -77,7 +77,7 @@
 tester = RubyTester(check_flush = check_flush, checks_to_complete = 100,
                     wakeup_frequency = 10, num_cpus = options.num_cpus)
 
-system = System(tester = tester, physmem = SimpleMemory())
+system = System(tester = tester, physmem = SimpleMemory(null = True))
 
 Ruby.create_system(options, system)
 
@@ -104,12 +104,6 @@
     #
     ruby_port.using_ruby_tester = True
 
-    #
-    # Ruby doesn't need the backing image of memory when running with
-    # the tester.
-    #
-    ruby_port.access_phys_mem = False
-
 # -----------------------
 # run simulation
 # -----------------------
diff -r 9934883ab246 -r b2c1502e2508 tests/configs/simple-timing-ruby.py
--- a/tests/configs/simple-timing-ruby.py	Sat Feb 23 00:40:44 2013 -0600
+++ b/tests/configs/simple-timing-ruby.py	Sat Feb 23 00:40:54 2013 -0600
@@ -67,7 +67,7 @@
 options.num_cpus = 1
 
 cpu = TimingSimpleCPU(cpu_id=0)
-system = System(cpu = cpu, physmem = SimpleMemory())
+system = System(cpu = cpu, physmem = SimpleMemory(null = True))
 
 Ruby.create_system(options, system)