src/sim/system.cc - testing/jenkins-gem5-prod - Git at Google

 /*
  * Copyright (c) 2011-2014,2017-2018 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Copyright (c) 2003-2006 The Regents of The University of Michigan
  * Copyright (c) 2011 Regents of the University of California
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met: redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer;
  * redistributions in binary form must reproduce the above copyright
  * notice, this list of conditions and the following disclaimer in the
  * documentation and/or other materials provided with the distribution;
  * neither the name of the copyright holders nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Authors: Steve Reinhardt
  *          Lisa Hsu
  *          Nathan Binkert
  *          Ali Saidi
  *          Rick Strong
  */

 #include "sim/system.hh"

 #include <algorithm>

 #include "arch/remote_gdb.hh"
 #include "arch/utility.hh"
 #include "base/loader/object_file.hh"
 #include "base/loader/symtab.hh"
 #include "base/str.hh"
 #include "base/trace.hh"
 #include "config/use_kvm.hh"
 #if USE_KVM
 #include "cpu/kvm/base.hh"
 #include "cpu/kvm/vm.hh"
 #endif
 #include "cpu/base.hh"
 #include "cpu/thread_context.hh"
 #include "debug/Loader.hh"
 #include "debug/WorkItems.hh"
 #include "mem/abstract_mem.hh"
 #include "mem/physical.hh"
 #include "params/System.hh"
 #include "sim/byteswap.hh"
 #include "sim/debug.hh"
 #include "sim/full_system.hh"

 /**
  * To avoid linking errors with LTO, only include the header if we
  * actually have a definition.
  */
 #if THE_ISA != NULL_ISA
 #include "kern/kernel_stats.hh"

 #endif

 using namespace std;
 using namespace TheISA;

 vector<System *> System::systemList;

 int System::numSystemsRunning = 0;

 System::System(Params *p)
     : MemObject(p), _systemPort("system_port", this),
       multiThread(p->multi_thread),
       pagePtr(0),
       init_param(p->init_param),
       physProxy(_systemPort, p->cache_line_size),
       kernelSymtab(nullptr),
       kernel(nullptr),
       loadAddrMask(p->load_addr_mask),
       loadAddrOffset(p->load_offset),
 #if USE_KVM
       kvmVM(p->kvm_vm),
 #else
       kvmVM(nullptr),
 #endif
       physmem(name() + ".physmem", p->memories, p->mmap_using_noreserve),
       memoryMode(p->mem_mode),
       _cacheLineSize(p->cache_line_size),
       workItemsBegin(0),
       workItemsEnd(0),
       numWorkIds(p->num_work_ids),
       thermalModel(p->thermal_model),
       _params(p),
       totalNumInsts(0),
       instEventQueue("system instruction-based event queue")
 {
     // add self to global system list
     systemList.push_back(this);

 #if USE_KVM
     if (kvmVM) {
         kvmVM->setSystem(this);
     }
 #endif

     if (FullSystem) {
         kernelSymtab = new SymbolTable;
         if (!debugSymbolTable)
             debugSymbolTable = new SymbolTable;
     }

     // check if the cache line size is a value known to work
     if (!(_cacheLineSize == 16 || _cacheLineSize == 32 ||
           _cacheLineSize == 64 || _cacheLineSize == 128))
         warn_once("Cache line size is neither 16, 32, 64 nor 128 bytes.\n");

     // Get the generic system master IDs
     MasterID tmp_id M5_VAR_USED;
     tmp_id = getMasterId(this, "writebacks");
     assert(tmp_id == Request::wbMasterId);
     tmp_id = getMasterId(this, "functional");
     assert(tmp_id == Request::funcMasterId);
     tmp_id = getMasterId(this, "interrupt");
     assert(tmp_id == Request::intMasterId);

     if (FullSystem) {
         if (params()->kernel == "") {
             inform("No kernel set for full system simulation. "
                    "Assuming you know what you're doing\n");
         } else {
             // Get the kernel code
             kernel = createObjectFile(params()->kernel);
             inform("kernel located at: %s", params()->kernel);

             if (kernel == NULL)
                 fatal("Could not load kernel file %s", params()->kernel);

             // setup entry points
             kernelStart = kernel->textBase();
             kernelEnd = kernel->bssBase() + kernel->bssSize();
             kernelEntry = kernel->entryPoint();

             // If load_addr_mask is set to 0x0, then auto-calculate
             // the smallest mask to cover all kernel addresses so gem5
             // can relocate the kernel to a new offset.
             if (loadAddrMask == 0) {
                 Addr shift_amt = findMsbSet(kernelEnd - kernelStart) + 1;
                 loadAddrMask = ((Addr)1 << shift_amt) - 1;
             }

             // load symbols
             if (!kernel->loadGlobalSymbols(kernelSymtab))
                 fatal("could not load kernel symbols\n");

             if (!kernel->loadLocalSymbols(kernelSymtab))
                 fatal("could not load kernel local symbols\n");

             if (!kernel->loadGlobalSymbols(debugSymbolTable))
                 fatal("could not load kernel symbols\n");

             if (!kernel->loadLocalSymbols(debugSymbolTable))
                 fatal("could not load kernel local symbols\n");

             // Loading only needs to happen once and after memory system is
             // connected so it will happen in initState()
         }

         for (const auto &obj_name : p->kernel_extras) {
             inform("Loading additional kernel object: %s", obj_name);
             ObjectFile *obj = createObjectFile(obj_name);
             fatal_if(!obj, "Failed to additional kernel object '%s'.\n",
                      obj_name);
             kernelExtras.push_back(obj);
         }
     }

     // increment the number of running systems
     numSystemsRunning++;

     // Set back pointers to the system in all memories
     for (int x = 0; x < params()->memories.size(); x++)
         params()->memories[x]->system(this);
 }

 System::~System()
 {
     delete kernelSymtab;
     delete kernel;

     for (uint32_t j = 0; j < numWorkIds; j++)
         delete workItemStats[j];
 }

 void
 System::init()
 {
     // check that the system port is connected
     if (!_systemPort.isConnected())
         panic("System port on %s is not connected.\n", name());
 }

 Port &
 System::getPort(const std::string &if_name, PortID idx)
 {
     // no need to distinguish at the moment (besides checking)
     return _systemPort;
 }

 void
 System::setMemoryMode(Enums::MemoryMode mode)
 {
     assert(drainState() == DrainState::Drained);
     memoryMode = mode;
 }

 bool System::breakpoint()
 {
     if (remoteGDB.size())
         return remoteGDB[0]->breakpoint();
     return false;
 }

 ContextID
 System::registerThreadContext(ThreadContext *tc, ContextID assigned)
 {
     int id = assigned;
     if (id == InvalidContextID) {
         // Find an unused context ID for this thread.
         id = 0;
         while (id < threadContexts.size() && threadContexts[id])
             id++;
     }

     if (threadContexts.size() <= id)
         threadContexts.resize(id + 1);

     fatal_if(threadContexts[id],
              "Cannot have two CPUs with the same id (%d)\n", id);

     threadContexts[id] = tc;

 #if THE_ISA != NULL_ISA
     int port = getRemoteGDBPort();
     if (port) {
         RemoteGDB *rgdb = new RemoteGDB(this, tc, port + id);
         rgdb->listen();

         BaseCPU *cpu = tc->getCpuPtr();
         if (cpu->waitForRemoteGDB()) {
             inform("%s: Waiting for a remote GDB connection on port %d.\n",
                    cpu->name(), rgdb->port());

             rgdb->connect();
         }
         if (remoteGDB.size() <= id) {
             remoteGDB.resize(id + 1);
         }

         remoteGDB[id] = rgdb;
     }
 #endif

     activeCpus.push_back(false);

     return id;
 }

 int
 System::numRunningContexts()
 {
     return std::count_if(
         threadContexts.cbegin(),
         threadContexts.cend(),
         [] (ThreadContext* tc) {
             return ((tc->status() != ThreadContext::Halted) &&
                     (tc->status() != ThreadContext::Halting));
         }
     );
 }

 void
 System::initState()
 {
     if (FullSystem) {
         for (int i = 0; i < threadContexts.size(); i++)
             TheISA::startupCPU(threadContexts[i], i);
         // Moved from the constructor to here since it relies on the
         // address map being resolved in the interconnect
         /**
          * Load the kernel code into memory
          */
         if (params()->kernel != "")  {
             if (params()->kernel_addr_check) {
                 // Validate kernel mapping before loading binary
                 if (!(isMemAddr((kernelStart & loadAddrMask) +
                                 loadAddrOffset) &&
                       isMemAddr((kernelEnd & loadAddrMask) +
                                 loadAddrOffset))) {
                     fatal("Kernel is mapped to invalid location (not memory). "
                           "kernelStart 0x(%x) - kernelEnd 0x(%x) %#x:%#x\n",
                           kernelStart,
                           kernelEnd, (kernelStart & loadAddrMask) +
                           loadAddrOffset,
                           (kernelEnd & loadAddrMask) + loadAddrOffset);
                 }
             }
             // Load program sections into memory
             kernel->loadSections(physProxy, loadAddrMask, loadAddrOffset);
             for (const auto &extra_kernel : kernelExtras) {
                 extra_kernel->loadSections(physProxy, loadAddrMask,
                                            loadAddrOffset);
             }

             DPRINTF(Loader, "Kernel start = %#x\n", kernelStart);
             DPRINTF(Loader, "Kernel end   = %#x\n", kernelEnd);
             DPRINTF(Loader, "Kernel entry = %#x\n", kernelEntry);
             DPRINTF(Loader, "Kernel loaded...\n");
         }
     }
 }

 void
 System::replaceThreadContext(ThreadContext *tc, ContextID context_id)
 {
     if (context_id >= threadContexts.size()) {
         panic("replaceThreadContext: bad id, %d >= %d\n",
               context_id, threadContexts.size());
     }

     threadContexts[context_id] = tc;
     if (context_id < remoteGDB.size())
         remoteGDB[context_id]->replaceThreadContext(tc);
 }

 bool
 System::validKvmEnvironment() const
 {
 #if USE_KVM
     if (threadContexts.empty())
         return false;

     for (auto tc : threadContexts) {
         if (dynamic_cast<BaseKvmCPU*>(tc->getCpuPtr()) == nullptr) {
             return false;
         }
     }
     return true;
 #else
     return false;
 #endif
 }

 Addr
 System::allocPhysPages(int npages)
 {
     Addr return_addr = pagePtr << PageShift;
     pagePtr += npages;

     Addr next_return_addr = pagePtr << PageShift;

     AddrRange m5opRange(0xffff0000, 0xffffffff);
     if (m5opRange.contains(next_return_addr)) {
         warn("Reached m5ops MMIO region\n");
         return_addr = 0xffffffff;
         pagePtr = 0xffffffff >> PageShift;
     }

     if ((pagePtr << PageShift) > physmem.totalSize())
         fatal("Out of memory, please increase size of physical memory.");
     return return_addr;
 }

 Addr
 System::memSize() const
 {
     return physmem.totalSize();
 }

 Addr
 System::freeMemSize() const
 {
    return physmem.totalSize() - (pagePtr << PageShift);
 }

 bool
 System::isMemAddr(Addr addr) const
 {
     return physmem.isMemAddr(addr);
 }

 void
 System::drainResume()
 {
     totalNumInsts = 0;
 }

 void
 System::serialize(CheckpointOut &cp) const
 {
     if (FullSystem)
         kernelSymtab->serialize("kernel_symtab", cp);
     SERIALIZE_SCALAR(pagePtr);
     serializeSymtab(cp);

     // also serialize the memories in the system
     physmem.serializeSection(cp, "physmem");
 }


 void
 System::unserialize(CheckpointIn &cp)
 {
     if (FullSystem)
         kernelSymtab->unserialize("kernel_symtab", cp);
     UNSERIALIZE_SCALAR(pagePtr);
     unserializeSymtab(cp);

     // also unserialize the memories in the system
     physmem.unserializeSection(cp, "physmem");
 }

 void
 System::regStats()
 {
     MemObject::regStats();

     for (uint32_t j = 0; j < numWorkIds ; j++) {
         workItemStats[j] = new Stats::Histogram();
         stringstream namestr;
         ccprintf(namestr, "work_item_type%d", j);
         workItemStats[j]->init(20)
                          .name(name() + "." + namestr.str())
                          .desc("Run time stat for" + namestr.str())
                          .prereq(*workItemStats[j]);
     }
 }

 void
 System::workItemEnd(uint32_t tid, uint32_t workid)
 {
     std::pair<uint32_t,uint32_t> p(tid, workid);
     if (!lastWorkItemStarted.count(p))
         return;

     Tick samp = curTick() - lastWorkItemStarted[p];
     DPRINTF(WorkItems, "Work item end: %d\t%d\t%lld\n", tid, workid, samp);

     if (workid >= numWorkIds)
         fatal("Got workid greater than specified in system configuration\n");

     workItemStats[workid]->sample(samp);
     lastWorkItemStarted.erase(p);
 }

 void
 System::printSystems()
 {
     ios::fmtflags flags(cerr.flags());

     vector<System *>::iterator i = systemList.begin();
     vector<System *>::iterator end = systemList.end();
     for (; i != end; ++i) {
         System *sys = *i;
         cerr << "System " << sys->name() << ": " << hex << sys << endl;
     }

     cerr.flags(flags);
 }

 void
 printSystems()
 {
     System::printSystems();
 }

 std::string
 System::stripSystemName(const std::string& master_name) const
 {
     if (startswith(master_name, name())) {
         return master_name.substr(name().size());
     } else {
         return master_name;
     }
 }

 MasterID
 System::lookupMasterId(const SimObject* obj) const
 {
     MasterID id = Request::invldMasterId;

     // number of occurrences of the SimObject pointer
     // in the master list.
     auto obj_number = 0;

     for (int i = 0; i < masters.size(); i++) {
         if (masters[i].obj == obj) {
             id = i;
             obj_number++;
         }
     }

     fatal_if(obj_number > 1,
         "Cannot lookup MasterID by SimObject pointer: "
         "More than one master is sharing the same SimObject\n");

     return id;
 }

 MasterID
 System::lookupMasterId(const std::string& master_name) const
 {
     std::string name = stripSystemName(master_name);

     for (int i = 0; i < masters.size(); i++) {
         if (masters[i].masterName == name) {
             return i;
         }
     }

     return Request::invldMasterId;
 }

 MasterID
 System::getGlobalMasterId(const std::string& master_name)
 {
     return _getMasterId(nullptr, master_name);
 }

 MasterID
 System::getMasterId(const SimObject* master, std::string submaster)
 {
     auto master_name = leafMasterName(master, submaster);
     return _getMasterId(master, master_name);
 }

 MasterID
 System::_getMasterId(const SimObject* master, const std::string& master_name)
 {
     std::string name = stripSystemName(master_name);

     // CPUs in switch_cpus ask for ids again after switching
     for (int i = 0; i < masters.size(); i++) {
         if (masters[i].masterName == name) {
             return i;
         }
     }

     // Verify that the statistics haven't been enabled yet
     // Otherwise objects will have sized their stat buckets and
     // they will be too small

     if (Stats::enabled()) {
         fatal("Can't request a masterId after regStats(). "
                 "You must do so in init().\n");
     }

     // Generate a new MasterID incrementally
     MasterID master_id = masters.size();

     // Append the new Master metadata to the group of system Masters.
     masters.emplace_back(master, name, master_id);

     return masters.back().masterId;
 }

 std::string
 System::leafMasterName(const SimObject* master, const std::string& submaster)
 {
     if (submaster.empty()) {
         return master->name();
     } else {
         // Get the full master name by appending the submaster name to
         // the root SimObject master name
         return master->name() + "." + submaster;
     }
 }

 std::string
 System::getMasterName(MasterID master_id)
 {
     if (master_id >= masters.size())
         fatal("Invalid master_id passed to getMasterName()\n");

     const auto& master_info = masters[master_id];
     return master_info.masterName;
 }

 System *
 SystemParams::create()
 {
     return new System(this);
 }
	/*
	* Copyright (c) 2011-2014,2017-2018 ARM Limited
	* All rights reserved
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Copyright (c) 2003-2006 The Regents of The University of Michigan
	* Copyright (c) 2011 Regents of the University of California
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met: redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer;
	* redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution;
	* neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	* Authors: Steve Reinhardt
	* Lisa Hsu
	* Nathan Binkert
	* Ali Saidi
	* Rick Strong
	*/

	#include "sim/system.hh"

	#include <algorithm>

	#include "arch/remote_gdb.hh"
	#include "arch/utility.hh"
	#include "base/loader/object_file.hh"
	#include "base/loader/symtab.hh"
	#include "base/str.hh"
	#include "base/trace.hh"
	#include "config/use_kvm.hh"
	#if USE_KVM
	#include "cpu/kvm/base.hh"
	#include "cpu/kvm/vm.hh"
	#endif
	#include "cpu/base.hh"
	#include "cpu/thread_context.hh"
	#include "debug/Loader.hh"
	#include "debug/WorkItems.hh"
	#include "mem/abstract_mem.hh"
	#include "mem/physical.hh"
	#include "params/System.hh"
	#include "sim/byteswap.hh"
	#include "sim/debug.hh"
	#include "sim/full_system.hh"

	/**
	* To avoid linking errors with LTO, only include the header if we
	* actually have a definition.
	*/
	#if THE_ISA != NULL_ISA
	#include "kern/kernel_stats.hh"

	#endif

	using namespace std;
	using namespace TheISA;

	vector<System *> System::systemList;

	int System::numSystemsRunning = 0;

	System::System(Params *p)
	: MemObject(p), _systemPort("system_port", this),
	multiThread(p->multi_thread),
	pagePtr(0),
	init_param(p->init_param),
	physProxy(_systemPort, p->cache_line_size),
	kernelSymtab(nullptr),
	kernel(nullptr),
	loadAddrMask(p->load_addr_mask),
	loadAddrOffset(p->load_offset),
	#if USE_KVM
	kvmVM(p->kvm_vm),
	#else
	kvmVM(nullptr),
	#endif
	physmem(name() + ".physmem", p->memories, p->mmap_using_noreserve),
	memoryMode(p->mem_mode),
	_cacheLineSize(p->cache_line_size),
	workItemsBegin(0),
	workItemsEnd(0),
	numWorkIds(p->num_work_ids),
	thermalModel(p->thermal_model),
	_params(p),
	totalNumInsts(0),
	instEventQueue("system instruction-based event queue")
	{
	// add self to global system list
	systemList.push_back(this);

	#if USE_KVM
	if (kvmVM) {
	kvmVM->setSystem(this);
	}
	#endif

	if (FullSystem) {
	kernelSymtab = new SymbolTable;
	if (!debugSymbolTable)
	debugSymbolTable = new SymbolTable;
	}

	// check if the cache line size is a value known to work
	if (!(_cacheLineSize == 16 \|\| _cacheLineSize == 32 \|\|
	_cacheLineSize == 64 \|\| _cacheLineSize == 128))
	warn_once("Cache line size is neither 16, 32, 64 nor 128 bytes.\n");

	// Get the generic system master IDs
	MasterID tmp_id M5_VAR_USED;
	tmp_id = getMasterId(this, "writebacks");
	assert(tmp_id == Request::wbMasterId);
	tmp_id = getMasterId(this, "functional");
	assert(tmp_id == Request::funcMasterId);
	tmp_id = getMasterId(this, "interrupt");
	assert(tmp_id == Request::intMasterId);

	if (FullSystem) {
	if (params()->kernel == "") {
	inform("No kernel set for full system simulation. "
	"Assuming you know what you're doing\n");
	} else {
	// Get the kernel code
	kernel = createObjectFile(params()->kernel);
	inform("kernel located at: %s", params()->kernel);

	if (kernel == NULL)
	fatal("Could not load kernel file %s", params()->kernel);

	// setup entry points
	kernelStart = kernel->textBase();
	kernelEnd = kernel->bssBase() + kernel->bssSize();
	kernelEntry = kernel->entryPoint();

	// If load_addr_mask is set to 0x0, then auto-calculate
	// the smallest mask to cover all kernel addresses so gem5
	// can relocate the kernel to a new offset.
	if (loadAddrMask == 0) {
	Addr shift_amt = findMsbSet(kernelEnd - kernelStart) + 1;
	loadAddrMask = ((Addr)1 << shift_amt) - 1;
	}

	// load symbols
	if (!kernel->loadGlobalSymbols(kernelSymtab))
	fatal("could not load kernel symbols\n");

	if (!kernel->loadLocalSymbols(kernelSymtab))
	fatal("could not load kernel local symbols\n");

	if (!kernel->loadGlobalSymbols(debugSymbolTable))
	fatal("could not load kernel symbols\n");

	if (!kernel->loadLocalSymbols(debugSymbolTable))
	fatal("could not load kernel local symbols\n");

	// Loading only needs to happen once and after memory system is
	// connected so it will happen in initState()
	}

	for (const auto &obj_name : p->kernel_extras) {
	inform("Loading additional kernel object: %s", obj_name);
	ObjectFile *obj = createObjectFile(obj_name);
	fatal_if(!obj, "Failed to additional kernel object '%s'.\n",
	obj_name);
	kernelExtras.push_back(obj);
	}
	}

	// increment the number of running systems
	numSystemsRunning++;

	// Set back pointers to the system in all memories
	for (int x = 0; x < params()->memories.size(); x++)
	params()->memories[x]->system(this);
	}

	System::~System()
	{
	delete kernelSymtab;
	delete kernel;

	for (uint32_t j = 0; j < numWorkIds; j++)
	delete workItemStats[j];
	}

	void
	System::init()
	{
	// check that the system port is connected
	if (!_systemPort.isConnected())
	panic("System port on %s is not connected.\n", name());
	}

	Port &
	System::getPort(const std::string &if_name, PortID idx)
	{
	// no need to distinguish at the moment (besides checking)
	return _systemPort;
	}

	void
	System::setMemoryMode(Enums::MemoryMode mode)
	{
	assert(drainState() == DrainState::Drained);
	memoryMode = mode;
	}

	bool System::breakpoint()
	{
	if (remoteGDB.size())
	return remoteGDB[0]->breakpoint();
	return false;
	}

	ContextID
	System::registerThreadContext(ThreadContext *tc, ContextID assigned)
	{
	int id = assigned;
	if (id == InvalidContextID) {
	// Find an unused context ID for this thread.
	id = 0;
	while (id < threadContexts.size() && threadContexts[id])
	id++;
	}

	if (threadContexts.size() <= id)
	threadContexts.resize(id + 1);

	fatal_if(threadContexts[id],
	"Cannot have two CPUs with the same id (%d)\n", id);

	threadContexts[id] = tc;

	#if THE_ISA != NULL_ISA
	int port = getRemoteGDBPort();
	if (port) {
	RemoteGDB *rgdb = new RemoteGDB(this, tc, port + id);
	rgdb->listen();

	BaseCPU *cpu = tc->getCpuPtr();
	if (cpu->waitForRemoteGDB()) {
	inform("%s: Waiting for a remote GDB connection on port %d.\n",
	cpu->name(), rgdb->port());

	rgdb->connect();
	}
	if (remoteGDB.size() <= id) {
	remoteGDB.resize(id + 1);
	}

	remoteGDB[id] = rgdb;
	}
	#endif

	activeCpus.push_back(false);

	return id;
	}

	int
	System::numRunningContexts()
	{
	return std::count_if(
	threadContexts.cbegin(),
	threadContexts.cend(),
	[] (ThreadContext* tc) {
	return ((tc->status() != ThreadContext::Halted) &&
	(tc->status() != ThreadContext::Halting));
	}
	);
	}

	void
	System::initState()
	{
	if (FullSystem) {
	for (int i = 0; i < threadContexts.size(); i++)
	TheISA::startupCPU(threadContexts[i], i);
	// Moved from the constructor to here since it relies on the
	// address map being resolved in the interconnect
	/**
	* Load the kernel code into memory
	*/
	if (params()->kernel != "") {
	if (params()->kernel_addr_check) {
	// Validate kernel mapping before loading binary
	if (!(isMemAddr((kernelStart & loadAddrMask) +
	loadAddrOffset) &&
	isMemAddr((kernelEnd & loadAddrMask) +
	loadAddrOffset))) {
	fatal("Kernel is mapped to invalid location (not memory). "
	"kernelStart 0x(%x) - kernelEnd 0x(%x) %#x:%#x\n",
	kernelStart,
	kernelEnd, (kernelStart & loadAddrMask) +
	loadAddrOffset,
	(kernelEnd & loadAddrMask) + loadAddrOffset);
	}
	}
	// Load program sections into memory
	kernel->loadSections(physProxy, loadAddrMask, loadAddrOffset);
	for (const auto &extra_kernel : kernelExtras) {
	extra_kernel->loadSections(physProxy, loadAddrMask,
	loadAddrOffset);
	}

	DPRINTF(Loader, "Kernel start = %#x\n", kernelStart);
	DPRINTF(Loader, "Kernel end = %#x\n", kernelEnd);
	DPRINTF(Loader, "Kernel entry = %#x\n", kernelEntry);
	DPRINTF(Loader, "Kernel loaded...\n");
	}
	}
	}

	void
	System::replaceThreadContext(ThreadContext *tc, ContextID context_id)
	{
	if (context_id >= threadContexts.size()) {
	panic("replaceThreadContext: bad id, %d >= %d\n",
	context_id, threadContexts.size());
	}

	threadContexts[context_id] = tc;
	if (context_id < remoteGDB.size())
	remoteGDB[context_id]->replaceThreadContext(tc);
	}

	bool
	System::validKvmEnvironment() const
	{
	#if USE_KVM
	if (threadContexts.empty())
	return false;

	for (auto tc : threadContexts) {
	if (dynamic_cast<BaseKvmCPU*>(tc->getCpuPtr()) == nullptr) {
	return false;
	}
	}
	return true;
	#else
	return false;
	#endif
	}

	Addr
	System::allocPhysPages(int npages)
	{
	Addr return_addr = pagePtr << PageShift;
	pagePtr += npages;

	Addr next_return_addr = pagePtr << PageShift;

	AddrRange m5opRange(0xffff0000, 0xffffffff);
	if (m5opRange.contains(next_return_addr)) {
	warn("Reached m5ops MMIO region\n");
	return_addr = 0xffffffff;
	pagePtr = 0xffffffff >> PageShift;
	}

	if ((pagePtr << PageShift) > physmem.totalSize())
	fatal("Out of memory, please increase size of physical memory.");
	return return_addr;
	}

	Addr
	System::memSize() const
	{
	return physmem.totalSize();
	}

	Addr
	System::freeMemSize() const
	{
	return physmem.totalSize() - (pagePtr << PageShift);
	}

	bool
	System::isMemAddr(Addr addr) const
	{
	return physmem.isMemAddr(addr);
	}

	void
	System::drainResume()
	{
	totalNumInsts = 0;
	}

	void
	System::serialize(CheckpointOut &cp) const
	{
	if (FullSystem)
	kernelSymtab->serialize("kernel_symtab", cp);
	SERIALIZE_SCALAR(pagePtr);
	serializeSymtab(cp);

	// also serialize the memories in the system
	physmem.serializeSection(cp, "physmem");
	}


	void
	System::unserialize(CheckpointIn &cp)
	{
	if (FullSystem)
	kernelSymtab->unserialize("kernel_symtab", cp);
	UNSERIALIZE_SCALAR(pagePtr);
	unserializeSymtab(cp);

	// also unserialize the memories in the system
	physmem.unserializeSection(cp, "physmem");
	}

	void
	System::regStats()
	{
	MemObject::regStats();

	for (uint32_t j = 0; j < numWorkIds ; j++) {
	workItemStats[j] = new Stats::Histogram();
	stringstream namestr;
	ccprintf(namestr, "work_item_type%d", j);
	workItemStats[j]->init(20)
	.name(name() + "." + namestr.str())
	.desc("Run time stat for" + namestr.str())
	.prereq(*workItemStats[j]);
	}
	}

	void
	System::workItemEnd(uint32_t tid, uint32_t workid)
	{
	std::pair<uint32_t,uint32_t> p(tid, workid);
	if (!lastWorkItemStarted.count(p))
	return;

	Tick samp = curTick() - lastWorkItemStarted[p];
	DPRINTF(WorkItems, "Work item end: %d\t%d\t%lld\n", tid, workid, samp);

	if (workid >= numWorkIds)
	fatal("Got workid greater than specified in system configuration\n");

	workItemStats[workid]->sample(samp);
	lastWorkItemStarted.erase(p);
	}

	void
	System::printSystems()
	{
	ios::fmtflags flags(cerr.flags());

	vector<System *>::iterator i = systemList.begin();
	vector<System *>::iterator end = systemList.end();
	for (; i != end; ++i) {
	System sys = i;
	cerr << "System " << sys->name() << ": " << hex << sys << endl;
	}

	cerr.flags(flags);
	}

	void
	printSystems()
	{
	System::printSystems();
	}

	std::string
	System::stripSystemName(const std::string& master_name) const
	{
	if (startswith(master_name, name())) {
	return master_name.substr(name().size());
	} else {
	return master_name;
	}
	}

	MasterID
	System::lookupMasterId(const SimObject* obj) const
	{
	MasterID id = Request::invldMasterId;

	// number of occurrences of the SimObject pointer
	// in the master list.
	auto obj_number = 0;

	for (int i = 0; i < masters.size(); i++) {
	if (masters[i].obj == obj) {
	id = i;
	obj_number++;
	}
	}

	fatal_if(obj_number > 1,
	"Cannot lookup MasterID by SimObject pointer: "
	"More than one master is sharing the same SimObject\n");

	return id;
	}

	MasterID
	System::lookupMasterId(const std::string& master_name) const
	{
	std::string name = stripSystemName(master_name);

	for (int i = 0; i < masters.size(); i++) {
	if (masters[i].masterName == name) {
	return i;
	}
	}

	return Request::invldMasterId;
	}

	MasterID
	System::getGlobalMasterId(const std::string& master_name)
	{
	return _getMasterId(nullptr, master_name);
	}

	MasterID
	System::getMasterId(const SimObject* master, std::string submaster)
	{
	auto master_name = leafMasterName(master, submaster);
	return _getMasterId(master, master_name);
	}

	MasterID
	System::_getMasterId(const SimObject* master, const std::string& master_name)
	{
	std::string name = stripSystemName(master_name);

	// CPUs in switch_cpus ask for ids again after switching
	for (int i = 0; i < masters.size(); i++) {
	if (masters[i].masterName == name) {
	return i;
	}
	}

	// Verify that the statistics haven't been enabled yet
	// Otherwise objects will have sized their stat buckets and
	// they will be too small

	if (Stats::enabled()) {
	fatal("Can't request a masterId after regStats(). "
	"You must do so in init().\n");
	}

	// Generate a new MasterID incrementally
	MasterID master_id = masters.size();

	// Append the new Master metadata to the group of system Masters.
	masters.emplace_back(master, name, master_id);

	return masters.back().masterId;
	}

	std::string
	System::leafMasterName(const SimObject* master, const std::string& submaster)
	{
	if (submaster.empty()) {
	return master->name();
	} else {
	// Get the full master name by appending the submaster name to
	// the root SimObject master name
	return master->name() + "." + submaster;
	}
	}

	std::string
	System::getMasterName(MasterID master_id)
	{
	if (master_id >= masters.size())
	fatal("Invalid master_id passed to getMasterName()\n");

	const auto& master_info = masters[master_id];
	return master_info.masterName;
	}

	System *
	SystemParams::create()
	{
	return new System(this);
	}