text: # Copyright (c) 2016 Georgia Institute of Technology
  # 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: Tushar Krishna
  
  import math
  import m5
  from m5.objects import *
  from m5.defines import buildEnv
  from m5.util import addToPath, fatal
  
  def define_options(parser):
      # By default, ruby uses the simple timing cpu
      parser.set_defaults(cpu_type="TimingSimpleCPU")
  
      parser.add_option("--topology", type="string", default="Crossbar",
                        help="check configs/topologies for complete set")
      parser.add_option("--mesh-rows", type="int", default=0,
                        help="the number of rows in the mesh topology")
      parser.add_option("--network", type="choice", default="simple",
                        choices=['simple', 'garnet2.0'],
                        help="'simple'|'garnet2.0'")
      parser.add_option("--router-latency", action="store", type="int",
                        default=1,
                        help="""number of pipeline stages in the garnet router.
                              Has to be >= 1.
                              Can be over-ridden on a per router basis
                              in the topology file.""")
      parser.add_option("--link-latency", action="store", type="int", default=1,
                        help="""latency of each link the simple/garnet networks.
                              Has to be >= 1.
                              Can be over-ridden on a per link basis
                              in the topology file.""")
      parser.add_option("--link-width-bits", action="store", type="int",
                        default=128,
                        help="width in bits for all links inside garnet.")
      parser.add_option("--vcs-per-vnet", action="store", type="int", default=4,
                        help="""number of virtual channels per virtual network
                              inside garnet network.""")
      parser.add_option("--routing-algorithm", action="store", type="int",
                        default=0,
                        help="""routing algorithm in network.
                              0: weight-based table
                              1: XY (for Mesh. see garnet2.0/RoutingUnit.cc)
                              2: Custom (see garnet2.0/RoutingUnit.cc""")
      parser.add_option("--network-fault-model", action="store_true",
                        default=False,
                        help="""enable network fault model:
                              see src/mem/ruby/network/fault_model/""")
      parser.add_option("--garnet-deadlock-threshold", action="store",
                        type="int", default=50000,
                        help="network-level deadlock threshold.")
  
  
  def create_network(options, ruby):
  
      # Set the network classes based on the command line options
      if options.network == "garnet2.0":
          NetworkClass = GarnetNetwork
          IntLinkClass = GarnetIntLink
          ExtLinkClass = GarnetExtLink
          RouterClass = GarnetRouter
          InterfaceClass = GarnetNetworkInterface
  
      else:
          NetworkClass = SimpleNetwork
          IntLinkClass = SimpleIntLink
          ExtLinkClass = SimpleExtLink
          RouterClass = Switch
          InterfaceClass = None
  
      # Instantiate the network object
      # so that the controllers can connect to it.
      network = NetworkClass(ruby_system = ruby, topology = options.topology,
              routers = [], ext_links = [], int_links = [], netifs = [])
  
      return (network, IntLinkClass, ExtLinkClass, RouterClass, InterfaceClass)
  
  def init_network(options, network, InterfaceClass):
  
      if options.network == "garnet2.0":
          network.num_rows = options.mesh_rows
          network.vcs_per_vnet = options.vcs_per_vnet
          network.ni_flit_size = options.link_width_bits / 8
          network.routing_algorithm = options.routing_algorithm
          network.garnet_deadlock_threshold = options.garnet_deadlock_threshold
  
      if options.network == "simple":
          network.setup_buffers()
  
      if InterfaceClass != None:
          netifs = [InterfaceClass(id=i) \
                    for (i,n) in enumerate(network.ext_links)]
          network.netifs = netifs
  
      if options.network_fault_model:
          assert(options.network == "garnet2.0")
          network.enable_fault_model = True
          network.fault_model = FaultModel()
  