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from abc import ABCMeta, abstractmethod
import m5
from m5.objects import *
from m5.proxy import *

m5.util.addToPath("../configs/")
from common import FSConfig
from common.Caches import *
from base_config import *
from common.cores.arm.O3_ARM_v7a import *
from common.Benchmarks import SysConfig

from common import SysPaths


class ArmSESystemUniprocessor(BaseSESystemUniprocessor):
    """Syscall-emulation builder for ARM uniprocessor systems.

    A small tweak of the syscall-emulation builder to use more
    representative cache configurations.
    """

    def __init__(self, **kwargs):
        super(ArmSESystemUniprocessor, self).__init__(**kwargs)

    def create_caches_private(self, cpu):
        # The atomic SE configurations do not use caches
        if self.mem_mode == "timing":
            # Use the more representative cache configuration
            cpu.addTwoLevelCacheHierarchy(
                O3_ARM_v7a_ICache(), O3_ARM_v7a_DCache(), O3_ARM_v7aL2()
            )


class LinuxArmSystemBuilder(object):
    """Mix-in that implements create_system.

    This mix-in is intended as a convenient way of adding an
    ARM-specific create_system method to a class deriving from one of
    the generic base systems.
    """

    def __init__(self, machine_type, aarch64_kernel, enable_dvm, **kwargs):
        """
        Arguments:
          machine_type -- String describing the platform to simulate
          num_cpus -- integer number of CPUs in the system
          use_ruby -- True if ruby is used instead of the classic memory system
        """
        self.machine_type = machine_type
        self.aarch64_kernel = aarch64_kernel
        self.enable_dvm = enable_dvm
        self.num_cpus = kwargs.get("num_cpus", 1)
        self.mem_size = kwargs.get("mem_size", "256MB")
        self.use_ruby = kwargs.get("use_ruby", False)

    def init_kvm(self, system):
        """Do KVM-specific system initialization.

        Arguments:
          system -- System to work on.
        """
        system.kvm_vm = KvmVM()

        # Arm KVM regressions will use a simulated GIC. This means that in
        # order to work we need to remove the system interface of the
        # generic timer from the DTB and we need to inform the MuxingKvmGic
        # class to use the gem5 GIC instead of relying on the host one
        GenericTimer.generateDeviceTree = SimObject.generateDeviceTree
        system.realview.gic.simulate_gic = True

    def create_system(self):
        if self.aarch64_kernel:
            gem5_kernel = "vmlinux.arm64"
            try:
                if issubclass(self.cpu_class, ArmV8KvmCPU):
                    disk_image = "m5_exit_addr.squashfs.arm64"
                else:
                    disk_image = "m5_exit.squashfs.arm64"
            except:
                disk_image = "m5_exit.squashfs.arm64"
        else:
            gem5_kernel = "vmlinux.arm"
            disk_image = "m5_exit.squashfs.arm"

        default_kernels = {
            "VExpress_GEM5_V1": gem5_kernel,
            "VExpress_GEM5_Foundation": gem5_kernel,
        }

        sc = SysConfig(None, self.mem_size, [disk_image], "/dev/sda")
        system = FSConfig.makeArmSystem(
            self.mem_mode,
            self.machine_type,
            self.num_cpus,
            sc,
            ruby=self.use_ruby,
        )

        # TODO: This is removing SECURITY and VIRTUALIZATION extensions
        # from AArch32 runs to fix long regressions. Find a fix or
        # remove EL3/EL2 support at AArch32
        if not self.aarch64_kernel:
            system.release = ArmRelease(extensions=["LPAE"])

        # We typically want the simulator to panic if the kernel
        # panics or oopses. This prevents the simulator from running
        # an obviously failed test case until the end of time.
        system.workload.panic_on_panic = True
        system.workload.panic_on_oops = True

        system.workload.object_file = SysPaths.binary(
            default_kernels[self.machine_type]
        )

        self.init_system(system)
        if self.enable_dvm:
            for cpu in system.cpu:
                for decoder in cpu.decoder:
                    decoder.dvm_enabled = True

        system.workload.dtb_filename = os.path.join(
            m5.options.outdir, "system.dtb"
        )
        system.generateDtb(system.workload.dtb_filename)
        return system


class LinuxArmFSSystem(LinuxArmSystemBuilder, BaseFSSystem):
    """Basic ARM full system builder."""

    def __init__(
        self,
        machine_type="VExpress_GEM5_Foundation",
        aarch64_kernel=True,
        enable_dvm=False,
        **kwargs
    ):
        """Initialize an ARM system that supports full system simulation.

        Note: Keyword arguments that are not listed below will be
        passed to the BaseFSSystem.

        Keyword Arguments:
          machine_type -- String describing the platform to simulate
        """
        BaseFSSystem.__init__(self, **kwargs)
        LinuxArmSystemBuilder.__init__(
            self, machine_type, aarch64_kernel, enable_dvm, **kwargs
        )

    def create_caches_private(self, cpu):
        # Use the more representative cache configuration
        cpu.addTwoLevelCacheHierarchy(
            O3_ARM_v7a_ICache(), O3_ARM_v7a_DCache(), O3_ARM_v7aL2()
        )


class LinuxArmFSSystemUniprocessor(
    LinuxArmSystemBuilder, BaseFSSystemUniprocessor
):
    """Basic ARM full system builder for uniprocessor systems.

    Note: This class is a specialization of the ArmFSSystem and is
    only really needed to provide backwards compatibility for existing
    test cases.
    """

    def __init__(
        self,
        machine_type="VExpress_GEM5_Foundation",
        aarch64_kernel=True,
        **kwargs
    ):
        BaseFSSystemUniprocessor.__init__(self, **kwargs)
        LinuxArmSystemBuilder.__init__(
            self, machine_type, aarch64_kernel, False, **kwargs
        )


class LinuxArmFSSwitcheroo(LinuxArmSystemBuilder, BaseFSSwitcheroo):
    """Uniprocessor ARM system prepared for CPU switching"""

    def __init__(
        self,
        machine_type="VExpress_GEM5_Foundation",
        aarch64_kernel=True,
        **kwargs
    ):
        BaseFSSwitcheroo.__init__(self, **kwargs)
        LinuxArmSystemBuilder.__init__(
            self, machine_type, aarch64_kernel, False, **kwargs
        )