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"""
This example runs a simple linux boot on the RiscvBoard.

Characteristics
---------------

* Runs exclusively on the RISC-V ISA with the classic caches
"""

import m5
from m5.objects import Root

from gem5.isas import ISA
from gem5.utils.requires import requires
from gem5.resources.resource import Resource
from gem5.components.processors.cpu_types import CPUTypes
from gem5.components.boards.riscv_board import RiscvBoard
from gem5.components.processors.simple_processor import SimpleProcessor

import argparse
import importlib

parser = argparse.ArgumentParser(
    description="A script to run the RISCV boot exit tests."
)

parser.add_argument(
    "-n",
    "--num-cpus",
    type=int,
    required=True,
    help="The number of CPUs.",
)

parser.add_argument(
    "-c",
    "--cpu",
    type=str,
    choices=("kvm", "atomic", "timing", "o3"),
    required=True,
    help="The CPU type.",
)

parser.add_argument(
    "-m",
    "--mem-system",
    type=str,
    choices=("classic", "mi_example",),
    required=True,
    help="The memory system.",
)

parser.add_argument(
    "-d",
    "--dram-class",
    type=str,
    required=True,
    help="The python class for the memory interface to use"
)

parser.add_argument(
    "-t",
    "--tick-exit",
    type=int,
    required=False,
    help="The tick to exit the simulation.",
)

parser.add_argument(
    "-r",
    "--resource-directory",
    type=str,
    required=False,
    help="The directory in which resources will be downloaded or exist.",
)

args = parser.parse_args()

# Run a check to ensure the right version of gem5 is being used.
requires(isa_required=ISA.RISCV)

if args.mem_system == "classic":
    from gem5.components.cachehierarchies.classic.\
        private_l1_private_l2_cache_hierarchy import \
            PrivateL1PrivateL2CacheHierarchy

    # Setup the cache hierarchy.
    cache_hierarchy = PrivateL1PrivateL2CacheHierarchy(
        l1d_size="32KiB", l1i_size="32KiB", l2_size="512KiB"
    )
elif args.mem_system == "mi_example":
    from gem5.components.cachehierarchies.ruby.\
        mi_example_cache_hierarchy import \
            MIExampleCacheHierarchy

    # Setup the cache hierarchy.
    cache_hierarchy = MIExampleCacheHierarchy(
        size="32KiB", assoc=8
    )

# Setup the system memory.
python_module = "gem5.components.memory.multi_channel"
memory_class = getattr(
    importlib.import_module(python_module), args.dram_class
)
memory = memory_class(size="4GiB")

# Setup a processor.
if args.cpu == "kvm":
    cpu_type = CPUTypes.KVM
elif args.cpu == "atomic":
    cpu_type = CPUTypes.ATOMIC
elif args.cpu == "timing":
    cpu_type = CPUTypes.TIMING
elif args.cpu == "o3":
    cpu_type = CPUTypes.O3
else:
    raise NotImplementedError(
        "CPU type '{}' is not supported in the boot tests.".format(args.cpu)
    )

processor = SimpleProcessor(cpu_type=cpu_type, num_cores=args.num_cpus)

# Setup the board.
board = RiscvBoard(
    clk_freq="1GHz",
    processor=processor,
    memory=memory,
    cache_hierarchy=cache_hierarchy,
)

# Set the Full System workload.
board.set_kernel_disk_workload(
    kernel=Resource(
        "riscv-bootloader-vmlinux-5.10",
        resource_directory=args.resource_directory,
    ),
    disk_image=Resource(
        "riscv-ubuntu-20.04-img",
        resource_directory=args.resource_directory,
    ),
)

root = Root(full_system=True, system=board)

m5.instantiate()

if args.tick_exit:
    exit_event = m5.simulate(args.tick_exit)
else:
    exit_event = m5.simulate()
print(
    "Exiting @ tick {} because {}.".format(m5.curTick(), exit_event.getCause())
)