# -*- coding: utf-8 -*-
""" This file creates a single CPU and a two-level cache system.
This script takes a single parameter which specifies a binary to execute.
If none is provided it executes 'hello' by default (mostly used for testing)

See Part 1, Chapter 3: Adding cache to the configuration script in the
learning_gem5 book for more information about this script.
This file exports options for the L1 I/D and L2 cache sizes.

IMPORTANT: If you modify this file, it's likely that the Learning gem5 book
           also needs to be updated. For now, email Jason <power.jg@gmail.com>

"""

from __future__ import print_function
from __future__ import absolute_import

# import the m5 (gem5) library created when gem5 is built
import m5
# import all of the SimObjects
from m5.objects import *

# Add the common scripts to our path
m5.util.addToPath('../../')

# import the caches which we made
from caches import *

# import the SimpleOpts module
from common import SimpleOpts

# Set the usage message to display
SimpleOpts.set_usage("usage: %prog [options] <binary to execute>")

# Finalize the arguments and grab the opts so we can pass it on to our objects
(opts, args) = SimpleOpts.parse_args()

# get ISA for the default binary to run. This is mostly for simple testing
isa = str(m5.defines.buildEnv['TARGET_ISA']).lower()

# Default to running 'hello', use the compiled ISA to find the binary
# grab the specific path to the binary
thispath = os.path.dirname(os.path.realpath(__file__))
binary = os.path.join(thispath, '',
			'tests/test-progs/hello/bin/')
                      #'tests/test-progs/hello/bin/', isa, 'linux/hello')

# Check if there was a binary passed in via the command line and error if
# there are too many arguments
if len(args) == 1:
    binary = args[0]
elif len(args) > 1:
    SimpleOpts.print_help()
    m5.fatal("Expected a binary to execute as positional argument")

# create the system we are going to simulate
system = System()

# Set the clock fequency of the system (and all of its children)
system.clk_domain = SrcClockDomain()
system.clk_domain.clock = '1GHz'
system.clk_domain.voltage_domain = VoltageDomain()

# Set up the system
system.mem_mode = 'timing'               # Use timing accesses
system.mem_ranges = [AddrRange('512MB')] # Create an address range

# Create a simple CPU 
system.cpu = DerivO3CPU(branchPred=LTAGE()) #TimingSimpleCPU()

# Create an L1 instruction and data cache
system.cpu.icache = L1ICache()
system.cpu.dcache = L1DCache()

# Connect the instruction and data caches to the CPU
system.cpu.icache.connectCPU(system.cpu)
system.cpu.dcache.connectCPU(system.cpu)


# Create a memory bus
system.membus = SystemXBar()

# Hook the CPU ports up to the l2bus
system.cpu.icache.connectBus(system.membus)
system.cpu.dcache.connectBus(system.membus)

# create the interrupt controller for the CPU
system.cpu.createInterruptController()

# For x86 only, make sure the interrupts are connected to the memory
# Note: these are directly connected to the memory bus and are not cached
if m5.defines.buildEnv['TARGET_ISA'] == "x86":
    system.cpu.interrupts[0].pio = system.membus.master
    system.cpu.interrupts[0].int_master = system.membus.slave
    system.cpu.interrupts[0].int_slave = system.membus.master

# Connect the system up to the membus
system.system_port = system.membus.slave

# Create a DDR3 memory controller
system.mem_ctrl = DDR3_1600_8x8()
system.mem_ctrl.range = system.mem_ranges[0]
system.mem_ctrl.port = system.membus.master

# Create a process for a simple "Hello World" application
process = Process()
# Set the command
# cmd is a list which begins with the executable (like argv)
process.cmd = [binary]
# Set the cpu to use the process as its workload and create thread contexts
system.cpu.workload = process
system.cpu.createThreads()

# set up the root SimObject and start the simulation
root = Root(full_system = False, system = system)
# instantiate all of the objects we've created above
m5.instantiate()

print("Beginning simulation!")
exit_event = m5.simulate()
print('Exiting @ tick %i because %s' % (m5.curTick(), exit_event.getCause()))