Clean up CPU stuff and make it use params structs

cpu/base_cpu.cc:
cpu/base_cpu.hh:
    Convert the CPU stuff to use a params struct
cpu/memtest/memtest.cc:
    The memory tester is really not a cpu, so don't derive from
    BaseCPU since it just makes things a pain in the butt.  Keep
    track of max loads in the memtest class now that the base class
    doesn't do it for us.
    Don't have any default parameters.
cpu/memtest/memtest.hh:
    The memory tester is really not a cpu, so don't derive from
    BaseCPU since it just makes things a pain in the butt.  Keep
    track of max loads in the memtest class now that the base class
    doesn't do it for us.
cpu/simple_cpu/simple_cpu.cc:
    Convert to use a params struct.
    remove default parameters
cpu/simple_cpu/simple_cpu.hh:
    convert to use a params struct
cpu/trace/opt_cpu.cc:
cpu/trace/opt_cpu.hh:
cpu/trace/trace_cpu.cc:
cpu/trace/trace_cpu.hh:
    this isn't really a cpu.  don't derive from BaseCPU
objects/MemTest.mpy:
    we only need one max_loads parameter
sim/main.cc:
    Don't check for the number of CPUs since we may be doing something
    else going on.  If we don't have anything to simulate, the
    simulator will exit anyway.

--HG--
extra : convert_revision : 2195a34a9ec90b5414324054ceb3bab643540dd5

12 files changed, 139 insertions, 206 deletions

diff --git a/cpu/base_cpu.cc b/cpu/base_cpu.cc
index 425ac8877..a17edd371 100644
--- a/cpu/base_cpu.cc
+++ b/cpu/base_cpu.cc
@@ -49,25 +49,12 @@ vector<BaseCPU *> BaseCPU::cpuList;
 int maxThreadsPerCPU = 1;
 
 #ifdef FULL_SYSTEM
-BaseCPU::BaseCPU(const string &_name, int _number_of_threads, bool _def_reg,
-                 Counter max_insts_any_thread,
-                 Counter max_insts_all_threads,
-                 Counter max_loads_any_thread,
-                 Counter max_loads_all_threads,
-                 System *_system, Tick freq,
-                 bool _function_trace, Tick _function_trace_start)
-    : SimObject(_name), frequency(freq), checkInterrupts(true),
-      deferRegistration(_def_reg), number_of_threads(_number_of_threads),
-      system(_system)
+BaseCPU::BaseCPU(Params *p)
+    : SimObject(p->name), frequency(p->freq), checkInterrupts(true),
+      params(p), number_of_threads(p->numberOfThreads), system(p->system)
 #else
-BaseCPU::BaseCPU(const string &_name, int _number_of_threads, bool _def_reg,
-                 Counter max_insts_any_thread,
-                 Counter max_insts_all_threads,
-                 Counter max_loads_any_thread,
-                 Counter max_loads_all_threads,
-                 bool _function_trace, Tick _function_trace_start)
-    : SimObject(_name), deferRegistration(_def_reg),
-      number_of_threads(_number_of_threads)
+BaseCPU::BaseCPU(Params *p)
+    : SimObject(p->name), params(p), number_of_threads(p->numberOfThreads)
 #endif
 {
     // add self to global list of CPUs
@@ -84,12 +71,12 @@ BaseCPU::BaseCPU(const string &_name, int _number_of_threads, bool _def_reg,
     //
     // set up instruction-count-based termination events, if any
     //
-    if (max_insts_any_thread != 0)
+    if (p->max_insts_any_thread != 0)
         for (int i = 0; i < number_of_threads; ++i)
-            new SimExitEvent(comInstEventQueue[i], max_insts_any_thread,
+            new SimExitEvent(comInstEventQueue[i], p->max_insts_any_thread,
                 "a thread reached the max instruction count");
 
-    if (max_insts_all_threads != 0) {
+    if (p->max_insts_all_threads != 0) {
         // allocate & initialize shared downcounter: each event will
         // decrement this when triggered; simulation will terminate
         // when counter reaches 0
@@ -98,7 +85,7 @@ BaseCPU::BaseCPU(const string &_name, int _number_of_threads, bool _def_reg,
         for (int i = 0; i < number_of_threads; ++i)
             new CountedExitEvent(comInstEventQueue[i],
                 "all threads reached the max instruction count",
-                max_insts_all_threads, *counter);
+                p->max_insts_all_threads, *counter);
     }
 
     // allocate per-thread load-based event queues
@@ -109,12 +96,12 @@ BaseCPU::BaseCPU(const string &_name, int _number_of_threads, bool _def_reg,
     //
     // set up instruction-count-based termination events, if any
     //
-    if (max_loads_any_thread != 0)
+    if (p->max_loads_any_thread != 0)
         for (int i = 0; i < number_of_threads; ++i)
-            new SimExitEvent(comLoadEventQueue[i], max_loads_any_thread,
+            new SimExitEvent(comLoadEventQueue[i], p->max_loads_any_thread,
                 "a thread reached the max load count");
 
-    if (max_loads_all_threads != 0) {
+    if (p->max_loads_all_threads != 0) {
         // allocate & initialize shared downcounter: each event will
         // decrement this when triggered; simulation will terminate
         // when counter reaches 0
@@ -123,7 +110,7 @@ BaseCPU::BaseCPU(const string &_name, int _number_of_threads, bool _def_reg,
         for (int i = 0; i < number_of_threads; ++i)
             new CountedExitEvent(comLoadEventQueue[i],
                 "all threads reached the max load count",
-                max_loads_all_threads, *counter);
+                p->max_loads_all_threads, *counter);
     }
 
 #ifdef FULL_SYSTEM
@@ -132,18 +119,18 @@ BaseCPU::BaseCPU(const string &_name, int _number_of_threads, bool _def_reg,
 #endif
 
     functionTracingEnabled = false;
-    if (_function_trace) {
+    if (p->functionTrace) {
         functionTraceStream = simout.find(csprintf("ftrace.%s", name()));
         currentFunctionStart = currentFunctionEnd = 0;
-        functionEntryTick = _function_trace_start;
+        functionEntryTick = p->functionTraceStart;
 
-        if (_function_trace_start == 0) {
+        if (p->functionTraceStart == 0) {
             functionTracingEnabled = true;
         } else {
             Event *e =
                 new EventWrapper<BaseCPU, &BaseCPU::enableFunctionTrace>(this,
                                                                          true);
-            e->schedule(_function_trace_start);
+            e->schedule(p->functionTraceStart);
         }
     }
 }
@@ -162,7 +149,7 @@ BaseCPU::~BaseCPU()
 void
 BaseCPU::init()
 {
-    if (!deferRegistration)
+    if (!params->deferRegistration)
         registerExecContexts();
 }
 
diff --git a/cpu/base_cpu.hh b/cpu/base_cpu.hh
index baa956aa8..dd1c7ac58 100644
--- a/cpu/base_cpu.hh
+++ b/cpu/base_cpu.hh
@@ -90,28 +90,31 @@ class BaseCPU : public SimObject
     virtual void haltContext(int thread_num) {}
 
   public:
-
+    struct Params
+    {
+        std::string name;
+        int numberOfThreads;
+        bool deferRegistration;
+        Counter max_insts_any_thread;
+        Counter max_insts_all_threads;
+        Counter max_loads_any_thread;
+        Counter max_loads_all_threads;
+        Tick freq;
+        bool functionTrace;
+        Tick functionTraceStart;
 #ifdef FULL_SYSTEM
-    BaseCPU(const std::string &_name, int _number_of_threads, bool _def_reg,
-            Counter max_insts_any_thread, Counter max_insts_all_threads,
-            Counter max_loads_any_thread, Counter max_loads_all_threads,
-            System *_system, Tick freq,
-            bool _function_trace = false, Tick _function_trace_start = 0);
-#else
-    BaseCPU(const std::string &_name, int _number_of_threads, bool _def_reg,
-            Counter max_insts_any_thread = 0,
-            Counter max_insts_all_threads = 0,
-            Counter max_loads_any_thread = 0,
-            Counter max_loads_all_threads = 0,
-            bool _function_trace = false, Tick _function_trace_start = 0);
+        System *system;
 #endif
+    };
+
+    const Params *params;
 
+    BaseCPU(Params *params);
     virtual ~BaseCPU();
 
     virtual void init();
     virtual void regStats();
 
-    bool deferRegistration;
     void registerExecContexts();
 
     /// Prepare for another CPU to take over execution.  Called by
diff --git a/cpu/memtest/memtest.cc b/cpu/memtest/memtest.cc
index e967c79da..14b119880 100644
--- a/cpu/memtest/memtest.cc
+++ b/cpu/memtest/memtest.cc
@@ -36,6 +36,7 @@
 
 #include "base/misc.hh"
 #include "base/statistics.hh"
+#include "cpu/exec_context.hh"
 #include "cpu/memtest/memtest.hh"
 #include "mem/cache/base_cache.hh"
 #include "mem/functional_mem/main_memory.hh"
@@ -59,10 +60,8 @@ MemTest::MemTest(const string &name,
                  unsigned _percentSourceUnaligned,
                  unsigned _percentDestUnaligned,
                  Addr _traceAddr,
-                 Counter max_loads_any_thread,
-                 Counter max_loads_all_threads)
-    : BaseCPU(name, 1, true, 0, 0, max_loads_any_thread,
-              max_loads_all_threads),
+                 Counter _max_loads)
+    : SimObject(name),
       tickEvent(this),
       cacheInterface(_cache_interface),
       mainMem(main_mem),
@@ -74,12 +73,13 @@ MemTest::MemTest(const string &name,
       progressInterval(_progressInterval),
       nextProgressMessage(_progressInterval),
       percentSourceUnaligned(_percentSourceUnaligned),
-      percentDestUnaligned(percentDestUnaligned)
+      percentDestUnaligned(percentDestUnaligned),
+      maxLoads(_max_loads)
 {
     vector<string> cmd;
     cmd.push_back("/bin/ls");
     vector<string> null_vec;
-    xc = new ExecContext(this ,0,mainMem,0);
+    xc = new ExecContext(NULL, 0, mainMem, 0);
 
     blockSize = cacheInterface->getBlockSize();
     blockAddrMask = blockSize - 1;
@@ -160,7 +160,8 @@ MemTest::completeRequest(MemReqPtr &req, uint8_t *data)
             nextProgressMessage += progressInterval;
         }
 
-        comLoadEventQueue[0]->serviceEvents(numReads);
+        if (numReads >= maxLoads)
+            SimExit(curTick, "Maximum number of loads reached!");
         break;
 
       case Write:
@@ -402,8 +403,7 @@ BEGIN_DECLARE_SIM_OBJECT_PARAMS(MemTest)
     Param<unsigned> percent_source_unaligned;
     Param<unsigned> percent_dest_unaligned;
     Param<Addr> trace_addr;
-    Param<Counter> max_loads_any_thread;
-    Param<Counter> max_loads_all_threads;
+    Param<Counter> max_loads;
 
 END_DECLARE_SIM_OBJECT_PARAMS(MemTest)
 
@@ -413,23 +413,17 @@ BEGIN_INIT_SIM_OBJECT_PARAMS(MemTest)
     INIT_PARAM(cache, "L1 cache"),
     INIT_PARAM(main_mem, "hierarchical memory"),
     INIT_PARAM(check_mem, "check memory"),
-    INIT_PARAM_DFLT(memory_size, "memory size", 65536),
-    INIT_PARAM_DFLT(percent_reads, "target read percentage", 65),
-    INIT_PARAM_DFLT(percent_copies, "target copy percentage", 0),
-    INIT_PARAM_DFLT(percent_uncacheable, "target uncacheable percentage", 10),
-    INIT_PARAM_DFLT(progress_interval,
-                    "progress report interval (in accesses)", 1000000),
-    INIT_PARAM_DFLT(percent_source_unaligned, "percent of copy source address "
-                    "that are unaligned", 50),
-    INIT_PARAM_DFLT(percent_dest_unaligned, "percent of copy dest address "
-                    "that are unaligned", 50),
-    INIT_PARAM_DFLT(trace_addr, "address to trace", 0),
-    INIT_PARAM_DFLT(max_loads_any_thread,
-                    "terminate when any thread reaches this load count",
-                    0),
-    INIT_PARAM_DFLT(max_loads_all_threads,
-                    "terminate when all threads have reached this load count",
-                    0)
+    INIT_PARAM(memory_size, "memory size"),
+    INIT_PARAM(percent_reads, "target read percentage"),
+    INIT_PARAM(percent_copies, "target copy percentage"),
+    INIT_PARAM(percent_uncacheable, "target uncacheable percentage"),
+    INIT_PARAM(progress_interval, "progress report interval (in accesses)"),
+    INIT_PARAM(percent_source_unaligned,
+               "percent of copy source address that are unaligned"),
+    INIT_PARAM(percent_dest_unaligned,
+               "percent of copy dest address that are unaligned"),
+    INIT_PARAM(trace_addr, "address to trace"),
+    INIT_PARAM(max_loads, "terminate when we have reached this load count")
 
 END_INIT_SIM_OBJECT_PARAMS(MemTest)
 
@@ -440,8 +434,7 @@ CREATE_SIM_OBJECT(MemTest)
                        check_mem, memory_size, percent_reads, percent_copies,
                        percent_uncacheable, progress_interval,
                        percent_source_unaligned, percent_dest_unaligned,
-                       trace_addr, max_loads_any_thread,
-                       max_loads_all_threads);
+                       trace_addr, max_loads);
 }
 
 REGISTER_SIM_OBJECT("MemTest", MemTest)
diff --git a/cpu/memtest/memtest.hh b/cpu/memtest/memtest.hh
index 43b17a713..45b2d24e8 100644
--- a/cpu/memtest/memtest.hh
+++ b/cpu/memtest/memtest.hh
@@ -26,20 +26,21 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef __MEMTEST_HH__
-#define __MEMTEST_HH__
+#ifndef __CPU_MEMTEST_MEMTEST_HH__
+#define __CPU_MEMTEST_MEMTEST_HH__
 
 #include <set>
 
 #include "base/statistics.hh"
-#include "cpu/base_cpu.hh"
-#include "cpu/exec_context.hh"
 #include "mem/functional_mem/functional_memory.hh"
 #include "mem/mem_interface.hh"
+#include "sim/eventq.hh"
+#include "sim/sim_exit.hh"
 #include "sim/sim_object.hh"
 #include "sim/stats.hh"
 
-class MemTest : public BaseCPU
+class ExecContext;
+class MemTest : public SimObject
 {
   public:
 
@@ -55,8 +56,7 @@ class MemTest : public BaseCPU
             unsigned _percentSourceUnaligned,
             unsigned _percentDestUnaligned,
             Addr _traceAddr,
-            Counter max_loads_any_thread,
-            Counter max_loads_all_threads);
+            Counter _max_loads);
 
     // register statistics
     virtual void regStats();
@@ -116,6 +116,7 @@ class MemTest : public BaseCPU
     Tick noResponseCycles;
 
     uint64_t numReads;
+    uint64_t maxLoads;
     Stats::Scalar<> numReadsStat;
     Stats::Scalar<> numWritesStat;
     Stats::Scalar<> numCopiesStat;
@@ -146,7 +147,7 @@ class MemCompleteEvent : public Event
     virtual const char *description();
 };
 
-#endif // __MEMTEST_HH__
+#endif // __CPU_MEMTEST_MEMTEST_HH__
 
 
 
diff --git a/cpu/simple_cpu/simple_cpu.cc b/cpu/simple_cpu/simple_cpu.cc
index 9079aba82..044ee9b9d 100644
--- a/cpu/simple_cpu/simple_cpu.cc
+++ b/cpu/simple_cpu/simple_cpu.cc
@@ -112,54 +112,22 @@ SimpleCPU::CacheCompletionEvent::description()
     return "SimpleCPU cache completion event";
 }
 
-#ifdef FULL_SYSTEM
-SimpleCPU::SimpleCPU(const string &_name,
-                     System *_system,
-                     Counter max_insts_any_thread,
-                     Counter max_insts_all_threads,
-                     Counter max_loads_any_thread,
-                     Counter max_loads_all_threads,
-                     AlphaITB *itb, AlphaDTB *dtb,
-                     FunctionalMemory *mem,
-                     MemInterface *icache_interface,
-                     MemInterface *dcache_interface,
-                     bool _def_reg, Tick freq,
-                     bool _function_trace, Tick _function_trace_start,
-                     int width)
-    : BaseCPU(_name, /* number_of_threads */ 1, _def_reg,
-              max_insts_any_thread, max_insts_all_threads,
-              max_loads_any_thread, max_loads_all_threads,
-              _system, freq, _function_trace, _function_trace_start),
-#else
-SimpleCPU::SimpleCPU(const string &_name, Process *_process,
-                     Counter max_insts_any_thread,
-                     Counter max_insts_all_threads,
-                     Counter max_loads_any_thread,
-                     Counter max_loads_all_threads,
-                     MemInterface *icache_interface,
-                     MemInterface *dcache_interface,
-                     bool _def_reg,
-                     bool _function_trace, Tick _function_trace_start,
-                     int width)
-    : BaseCPU(_name, /* number_of_threads */ 1, _def_reg,
-              max_insts_any_thread, max_insts_all_threads,
-              max_loads_any_thread, max_loads_all_threads,
-              _function_trace, _function_trace_start),
-#endif
-      tickEvent(this, width), xc(NULL), cacheCompletionEvent(this)
+SimpleCPU::SimpleCPU(Params *p)
+    : BaseCPU(p), tickEvent(this, p->width), xc(NULL),
+      cacheCompletionEvent(this)
 {
     _status = Idle;
 #ifdef FULL_SYSTEM
-    xc = new ExecContext(this, 0, system, itb, dtb, mem);
+    xc = new ExecContext(this, 0, p->system, p->itb, p->dtb, p->mem);
 
     // initialize CPU, including PC
     TheISA::initCPU(&xc->regs);
 #else
-    xc = new ExecContext(this, /* thread_num */ 0, _process, /* asid */ 0);
+    xc = new ExecContext(this, /* thread_num */ 0, p->process, /* asid */ 0);
 #endif // !FULL_SYSTEM
 
-    icacheInterface = icache_interface;
-    dcacheInterface = dcache_interface;
+    icacheInterface = p->icache_interface;
+    dcacheInterface = p->dcache_interface;
 
     memReq = new MemReq();
     memReq->xc = xc;
@@ -850,71 +818,67 @@ END_DECLARE_SIM_OBJECT_PARAMS(SimpleCPU)
 
 BEGIN_INIT_SIM_OBJECT_PARAMS(SimpleCPU)
 
-    INIT_PARAM_DFLT(max_insts_any_thread,
-                    "terminate when any thread reaches this inst count",
-                    0),
-    INIT_PARAM_DFLT(max_insts_all_threads,
-                    "terminate when all threads have reached this inst count",
-                    0),
-    INIT_PARAM_DFLT(max_loads_any_thread,
-                    "terminate when any thread reaches this load count",
-                    0),
-    INIT_PARAM_DFLT(max_loads_all_threads,
-                    "terminate when all threads have reached this load count",
-                    0),
+    INIT_PARAM(max_insts_any_thread,
+               "terminate when any thread reaches this inst count"),
+    INIT_PARAM(max_insts_all_threads,
+               "terminate when all threads have reached this inst count"),
+    INIT_PARAM(max_loads_any_thread,
+               "terminate when any thread reaches this load count"),
+    INIT_PARAM(max_loads_all_threads,
+               "terminate when all threads have reached this load count"),
 
 #ifdef FULL_SYSTEM
     INIT_PARAM(itb, "Instruction TLB"),
     INIT_PARAM(dtb, "Data TLB"),
     INIT_PARAM(mem, "memory"),
     INIT_PARAM(system, "system object"),
-    INIT_PARAM_DFLT(mult, "system clock multiplier", 1),
+    INIT_PARAM(mult, "system clock multiplier"),
 #else
     INIT_PARAM(workload, "processes to run"),
 #endif // FULL_SYSTEM
 
-    INIT_PARAM_DFLT(icache, "L1 instruction cache object", NULL),
-    INIT_PARAM_DFLT(dcache, "L1 data cache object", NULL),
-    INIT_PARAM_DFLT(defer_registration, "defer registration with system "
-                    "(for sampling)", false),
-
-    INIT_PARAM_DFLT(width, "cpu width", 1),
-    INIT_PARAM_DFLT(function_trace, "Enable function trace", false),
-    INIT_PARAM_DFLT(function_trace_start, "Cycle to start function trace", 0)
+    INIT_PARAM(icache, "L1 instruction cache object"),
+    INIT_PARAM(dcache, "L1 data cache object"),
+    INIT_PARAM(defer_registration, "defer system registration (for sampling)"),
+    INIT_PARAM(width, "cpu width"),
+    INIT_PARAM(function_trace, "Enable function trace"),
+    INIT_PARAM(function_trace_start, "Cycle to start function trace")
 
 END_INIT_SIM_OBJECT_PARAMS(SimpleCPU)
 
 
 CREATE_SIM_OBJECT(SimpleCPU)
 {
-    SimpleCPU *cpu;
 #ifdef FULL_SYSTEM
     if (mult != 1)
         panic("processor clock multiplier must be 1\n");
+#endif
 
-    cpu = new SimpleCPU(getInstanceName(), system,
-                        max_insts_any_thread, max_insts_all_threads,
-                        max_loads_any_thread, max_loads_all_threads,
-                        itb, dtb, mem,
-                        (icache) ? icache->getInterface() : NULL,
-                        (dcache) ? dcache->getInterface() : NULL,
-                        defer_registration,
-                        ticksPerSecond * mult,
-                        function_trace, function_trace_start,
-                        width);
-#else
-
-    cpu = new SimpleCPU(getInstanceName(), workload,
-                        max_insts_any_thread, max_insts_all_threads,
-                        max_loads_any_thread, max_loads_all_threads,
-                        (icache) ? icache->getInterface() : NULL,
-                        (dcache) ? dcache->getInterface() : NULL,
-                        defer_registration,
-                        function_trace, function_trace_start,
-                        width);
+    SimpleCPU::Params *params = new SimpleCPU::Params();
+    params->name = getInstanceName();
+    params->numberOfThreads = 1;
+    params->max_insts_any_thread = max_insts_any_thread;
+    params->max_insts_all_threads = max_insts_all_threads;
+    params->max_loads_any_thread = max_loads_any_thread;
+    params->max_loads_all_threads = max_loads_all_threads;
+    params->deferRegistration = defer_registration;
+    params->freq = ticksPerSecond;
+    params->functionTrace = function_trace;
+    params->functionTraceStart = function_trace_start;
+    params->icache_interface = (icache) ? icache->getInterface() : NULL;
+    params->dcache_interface = (dcache) ? dcache->getInterface() : NULL;
+    params->width = width;
 
-#endif // FULL_SYSTEM
+#ifdef FULL_SYSTEM
+    params->itb = itb;
+    params->dtb = dtb;
+    params->mem = mem;
+    params->system = system;
+#else
+    params->process = workload;
+#endif
 
+    SimpleCPU *cpu = new SimpleCPU(params);
     return cpu;
 }
 
diff --git a/cpu/simple_cpu/simple_cpu.hh b/cpu/simple_cpu/simple_cpu.hh
index 731b3ddbc..0283545f4 100644
--- a/cpu/simple_cpu/simple_cpu.hh
+++ b/cpu/simple_cpu/simple_cpu.hh
@@ -122,32 +122,24 @@ class SimpleCPU : public BaseCPU
       }
     };
 
+  public:
+    struct Params : public BaseCPU::Params
+    {
+        MemInterface *icache_interface;
+        MemInterface *dcache_interface;
+        int width;
 #ifdef FULL_SYSTEM
-
-    SimpleCPU(const std::string &_name,
-              System *_system,
-              Counter max_insts_any_thread, Counter max_insts_all_threads,
-              Counter max_loads_any_thread, Counter max_loads_all_threads,
-              AlphaITB *itb, AlphaDTB *dtb, FunctionalMemory *mem,
-              MemInterface *icache_interface, MemInterface *dcache_interface,
-              bool _def_reg, Tick freq,
-              bool _function_trace, Tick _function_trace_start, int width);
-
+        AlphaITB *itb;
+        AlphaDTB *dtb;
+        FunctionalMemory *mem;
 #else
-
-    SimpleCPU(const std::string &_name, Process *_process,
-              Counter max_insts_any_thread,
-              Counter max_insts_all_threads,
-              Counter max_loads_any_thread,
-              Counter max_loads_all_threads,
-              MemInterface *icache_interface, MemInterface *dcache_interface,
-              bool _def_reg,
-              bool _function_trace, Tick _function_trace_start, int width);
-
+        Process *process;
 #endif
-
+    };
+    SimpleCPU(Params *params);
     virtual ~SimpleCPU();
 
+  public:
     // execution context
     ExecContext *xc;
 
diff --git a/cpu/trace/opt_cpu.cc b/cpu/trace/opt_cpu.cc
index 77211e382..15b53d46e 100644
--- a/cpu/trace/opt_cpu.cc
+++ b/cpu/trace/opt_cpu.cc
@@ -48,7 +48,7 @@ OptCPU::OptCPU(const string &name,
                int block_size,
                int cache_size,
                int _assoc)
-    : BaseCPU(name, 1, true), tickEvent(this), trace(_trace),
+    : SimObject(name), tickEvent(this), trace(_trace),
       numBlks(cache_size/block_size), assoc(_assoc), numSets(numBlks/assoc),
       setMask(numSets - 1)
 {
diff --git a/cpu/trace/opt_cpu.hh b/cpu/trace/opt_cpu.hh
index 847147b3c..7f6aa3e18 100644
--- a/cpu/trace/opt_cpu.hh
+++ b/cpu/trace/opt_cpu.hh
@@ -32,14 +32,14 @@
  * trace to access a fully associative cache with optimal replacement.
  */
 
-#ifndef __OPT_CPU_HH__
-#define __OPT_CPU_HH__
+#ifndef __CPU_TRACE_OPT_CPU_HH__
+#define __CPU_TRACE_OPT_CPU_HH__
 
 #include <vector>
 
-#include "cpu/base_cpu.hh"
 #include "mem/mem_req.hh" // for MemReqPtr
 #include "sim/eventq.hh" // for Event
+#include "sim/sim_object.hh"
 
 // Forward Declaration
 class MemTraceReader;
@@ -47,8 +47,9 @@ class MemTraceReader;
 /**
  * A CPU object to simulate a fully-associative cache with optimal replacement.
  */
-class OptCPU : public BaseCPU
+class OptCPU : public SimObject
 {
+  private:
     typedef int RefIndex;
 
     typedef std::vector<RefIndex> L3Table;
@@ -219,4 +220,4 @@ class OptCPU : public BaseCPU
     void tick();
 };
 
-#endif
+#endif // __CPU_TRACE_OPT_CPU_HH__
diff --git a/cpu/trace/trace_cpu.cc b/cpu/trace/trace_cpu.cc
index f1160337a..1902d0be4 100644
--- a/cpu/trace/trace_cpu.cc
+++ b/cpu/trace/trace_cpu.cc
@@ -47,7 +47,7 @@ TraceCPU::TraceCPU(const string &name,
                    MemInterface *icache_interface,
                    MemInterface *dcache_interface,
                    MemTraceReader *data_trace)
-    : BaseCPU(name, 4, true), icacheInterface(icache_interface),
+    : SimObject(name), icacheInterface(icache_interface),
       dcacheInterface(dcache_interface),
       dataTrace(data_trace), outstandingRequests(0), tickEvent(this)
 {
diff --git a/cpu/trace/trace_cpu.hh b/cpu/trace/trace_cpu.hh
index 1711646a8..cdac4bb4f 100644
--- a/cpu/trace/trace_cpu.hh
+++ b/cpu/trace/trace_cpu.hh
@@ -32,14 +32,14 @@
  * provided memory hierarchy.
  */
 
-#ifndef __TRACE_CPU_HH__
-#define __TRACE_CPU_HH__
+#ifndef __CPU_TRACE_TRACE_CPU_HH__
+#define __CPU_TRACE_TRACE_CPU_HH__
 
 #include <string>
 
-#include "cpu/base_cpu.hh"
 #include "mem/mem_req.hh" // for MemReqPtr
 #include "sim/eventq.hh" // for Event
+#include "sim/sim_object.hh"
 
 // Forward declaration.
 class MemInterface;
@@ -48,8 +48,9 @@ class MemTraceReader;
 /**
  * A cpu object for running memory traces through a memory hierarchy.
  */
-class TraceCPU : public BaseCPU
+class TraceCPU : public SimObject
 {
+  private:
     /** Interface for instruction trace requests, if any. */
     MemInterface *icacheInterface;
     /** Interface for data trace requests, if any. */
@@ -133,5 +134,5 @@ class TraceCompleteEvent : public Event
     virtual const char *description();
 };
 
-#endif //__TRACE_CPU_HH__
+#endif // __CPU_TRACE_TRACE_CPU_HH__
 
diff --git a/objects/MemTest.mpy b/objects/MemTest.mpy
index 1ec33a30c..af14ed9c3 100644
--- a/objects/MemTest.mpy
+++ b/objects/MemTest.mpy
@@ -3,10 +3,7 @@ simobj MemTest(SimObject):
     cache = Param.BaseCache("L1 cache")
     check_mem = Param.FunctionalMemory("check memory")
     main_mem = Param.FunctionalMemory("hierarchical memory")
-    max_loads_all_threads = Param.Counter(0,
-        "terminate when all threads have reached this load count")
-    max_loads_any_thread = Param.Counter(0,
-        "terminate when any thread reaches this load count")
+    max_loads = Param.Counter("number of loads to execute")
     memory_size = Param.Int(65536, "memory size")
     percent_copies = Param.Percent(0, "target copy percentage")
     percent_dest_unaligned = Param.Percent(50,
diff --git a/sim/main.cc b/sim/main.cc
index 4352a90f4..c15d24453 100644
--- a/sim/main.cc
+++ b/sim/main.cc
@@ -402,12 +402,6 @@ main(int argc, char **argv)
     // Reset to put the stats in a consistent state.
     Stats::reset();
 
-    // Nothing to simulate if we don't have at least one CPU somewhere.
-    if (BaseCPU::numSimulatedCPUs() == 0) {
-        cerr << "Fatal: no CPUs to simulate." << endl;
-        exit(1);
-    }
-
     warn("Entering event queue.  Starting simulation...\n");
     SimStartup();
     while (!mainEventQueue.empty()) {