diff -r b0fa6b872f40 -r d305b09bb487 src/mem/ruby/system/System.cc
--- a/src/mem/ruby/system/System.cc	Thu Jan 24 12:29:00 2013 -0600
+++ b/src/mem/ruby/system/System.cc	Mon Jan 28 05:55:42 2013 -0600
@@ -69,7 +69,7 @@
     if (m_memory_size_bytes == 0) {
         m_memory_size_bits = 0;
     } else {
-        m_memory_size_bits = floorLog2(m_memory_size_bytes);
+        m_memory_size_bits = ceilLog2(m_memory_size_bytes);
     }
 
     g_system_ptr = this;