src/sim/Root.py

   1 # Copyright (c) 2005-2007 The Regents of The University of Michigan
   2 # Copyright (c) 2010-2013 Advanced Micro Devices, Inc.
   3 # Copyright (c) 2013 Mark D. Hill and David A. Wood
   4 # All rights reserved.
   5 #
   6 # Redistribution and use in source and binary forms, with or without
   7 # modification, are permitted provided that the following conditions are
   8 # met: redistributions of source code must retain the above copyright
   9 # notice, this list of conditions and the following disclaimer;
  10 # redistributions in binary form must reproduce the above copyright
  11 # notice, this list of conditions and the following disclaimer in the
  12 # documentation and/or other materials provided with the distribution;
  13 # neither the name of the copyright holders nor the names of its
  14 # contributors may be used to endorse or promote products derived from
  15 # this software without specific prior written permission.
  16 #
  17 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  19 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  20 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  23 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  24 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  27 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28 #
  29 # Authors: Nathan Binkert
  30
  31 from m5.SimObject import SimObject
  32 from m5.params import *
  33 from m5.util import fatal
  34
  35 class Root(SimObject):
  36
  37     _the_instance = None
  38
  39     def __new__(cls, **kwargs):
  40         if Root._the_instance:
  41             fatal("Attempt to allocate multiple instances of Root.")
  42             return None
  43
  44         # first call: allocate the unique instance
  45         #
  46         # If SimObject ever implements __new__, we may want to pass
  47         # kwargs here, but for now this goes straight to
  48         # object.__new__ which prints an ugly warning if you pass it
  49         # args.  Seems like a bad design but that's the way it is.
  50         Root._the_instance = SimObject.__new__(cls)
  51         return Root._the_instance
  52
  53     @classmethod
  54     def getInstance(cls):
  55         return Root._the_instance
  56
  57     def path(self):
  58         return 'root'
  59
  60     type = 'Root'
  61     cxx_header = "sim/root.hh"
  62
  63     # By default, root sim object and hence all other sim objects schedule
  64     # event on the eventq with index 0.
  65     eventq_index = 0
  66
  67     # Simulation Quantum for multiple main event queue simulation.
  68     # Needs to be set explicitly for a multi-eventq simulation.
  69     sim_quantum = Param.Tick(0, "simulation quantum")
  70
  71     full_system = Param.Bool("if this is a full system simulation")
  72
  73     # Time syncing prevents the simulation from running faster than real time.
  74     time_sync_enable = Param.Bool(False, "whether time syncing is enabled")
  75     time_sync_period = Param.Clock("100ms", "how often to sync with real time")
  76     time_sync_spin_threshold = \
  77             Param.Clock("100us", "when less than this much time is left, spin")