# Copyright (c) 2009, 2012-2013, 2015-2022 ARM Limited
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from m5.params import *
from m5.options import *
from m5.SimObject import *
from m5.util.fdthelper import *

from m5.objects.System import System
from m5.objects.ArmSemihosting import ArmSemihosting

from typing import Any


class SveVectorLength(UInt8):
    min = 1
    max = 16


class SmeVectorLength(UInt8):
    min = 1
    max = 16

    def _check(self):
        super()._check()

        # SME needs to be a whole power of 2. We already know value is
        # not zero. Hence:
        if self.value & (self.value - 1) != 0:
            raise TypeError(
                "SME vector length is not a power of 2: %d" % self.value
            )


class ArmExtension(ScopedEnum):
    vals = [
        # Armv8.1
        "FEAT_VHE",
        "FEAT_PAN",
        "FEAT_LSE",
        "FEAT_HPDS",
        "FEAT_VMID16",
        "FEAT_RDM",
        # Armv8.2
        "FEAT_SVE",
        "FEAT_UAO",
        "FEAT_LVA",  # Optional in Armv8.2
        "FEAT_LPA",  # Optional in Armv8.2
        # Armv8.3
        "FEAT_FCMA",
        "FEAT_JSCVT",
        "FEAT_PAuth",
        # Armv8.4
        "FEAT_SEL2",
        # Armv9.2
        "FEAT_SME",  # Optional in Armv9.2
        # Others
        "SECURITY",
        "LPAE",
        "VIRTUALIZATION",
        "CRYPTO",
        "TME",
    ]


class ArmRelease(SimObject):
    type = "ArmRelease"
    cxx_header = "arch/arm/system.hh"
    cxx_class = "gem5::ArmRelease"

    extensions = VectorParam.ArmExtension([], "ISA extensions")

    def add(self, new_ext: ArmExtension) -> None:
        """
        Add the provided extension (ArmExtension) to the system
        The method is discarding pre-existing values
        """
        if new_ext.value not in [ext.value for ext in self.extensions]:
            self.extensions.append(new_ext)

    def remove(self, ext: ArmExtension) -> None:
        """
        Remove the provided extension (ArmExtension) from the system
        """
        for curr_ext in list(self.extensions):
            if curr_ext.value == ext.value:
                self.extensions.remove(curr_ext)

    def has(self, new_ext: ArmExtension) -> bool:
        """
        Is the system implementing the provided extension (ArmExtension) ?
        """
        if new_ext.value not in [ext.value for ext in self.extensions]:
            return False
        else:
            return True

    @classmethod
    def for_kvm(cls) -> Any:
        """
        Generates an ArmRelease for KVM. It simply extracts EL2/EL3 support
        from the current cls object
        """
        release = cls()
        release.remove(ArmExtension("SECURITY"))
        release.remove(ArmExtension("VIRTUALIZATION"))
        return release


class Armv8(ArmRelease):
    extensions = ["LPAE", "VIRTUALIZATION", "SECURITY"]


class ArmDefaultRelease(Armv8):
    extensions = Armv8.extensions + [
        # Armv8.1
        "FEAT_LSE",
        "FEAT_PAN",
        "FEAT_HPDS",
        "FEAT_VMID16",
        "FEAT_RDM",
        # Armv8.2
        "FEAT_UAO",
        "FEAT_LVA",
        "FEAT_LPA",
        "FEAT_SVE",
        # Armv8.3
        "FEAT_FCMA",
        "FEAT_JSCVT",
        "FEAT_PAuth",
        # Armv8.4
        "FEAT_SEL2",
        # Armv9.2
        "FEAT_SME",
    ]


class Armv81(Armv8):
    extensions = Armv8.extensions + [
        "FEAT_LSE",
        "FEAT_VHE",
        "FEAT_PAN",
        "FEAT_HPDS",
        "FEAT_VMID16",
        "FEAT_RDM",
    ]


class Armv82(Armv81):
    extensions = Armv81.extensions + [
        "FEAT_UAO",
        "FEAT_LVA",
        "FEAT_LPA",
        "FEAT_SVE",
    ]


class Armv83(Armv82):
    extensions = Armv82.extensions + ["FEAT_FCMA", "FEAT_JSCVT", "FEAT_PAuth"]


class Armv84(Armv83):
    extensions = Armv83.extensions + ["FEAT_SEL2"]


class Armv92(Armv84):
    extensions = Armv84.extensions + ["FEAT_SME"]


class ArmSystem(System):
    type = "ArmSystem"
    cxx_header = "arch/arm/system.hh"
    cxx_class = "gem5::ArmSystem"

    release = Param.ArmRelease(ArmDefaultRelease(), "Arm Release")

    multi_proc = Param.Bool(True, "Multiprocessor system?")
    gic_cpu_addr = Param.Addr(0, "Addres of the GIC CPU interface")
    reset_addr = Param.Addr(0x0, "Reset address (ARMv8)")
    auto_reset_addr = Param.Bool(
        True,
        "Determine reset address from kernel entry point if no boot loader",
    )
    highest_el_is_64 = Param.Bool(
        True,
        "True if the register width of the highest implemented exception level "
        "is 64 bits (ARMv8)",
    )
    phys_addr_range_64 = Param.UInt8(
        40,
        "Supported physical address range in bits when using AArch64 (ARMv8)",
    )
    have_large_asid_64 = Param.Bool(
        False, "True if ASID is 16 bits in AArch64 (ARMv8)"
    )
    sve_vl = Param.SveVectorLength(
        1, "SVE vector length in quadwords (128-bit)"
    )
    sme_vl = Param.SveVectorLength(
        1, "SME vector length in quadwords (128-bit)"
    )
    semihosting = Param.ArmSemihosting(
        NULL,
        "Enable support for the Arm semihosting by settings this parameter",
    )

    # Set to true if simulation provides a PSCI implementation
    # This flag will be checked when auto-generating
    # a PSCI node. A client (e.g Linux) would then be able to
    # know if it can use the PSCI APIs
    _have_psci = False

    def generateDtb(self, filename):
        """
        Autogenerate DTB. Arguments are the folder where the DTB
        will be stored, and the name of the DTB file.
        """
        state = FdtState(addr_cells=2, size_cells=2, cpu_cells=1)
        rootNode = self.generateDeviceTree(state)

        fdt = Fdt()
        fdt.add_rootnode(rootNode)
        fdt.writeDtbFile(filename)

    def generateDeviceTree(self, state):
        # Generate a device tree root node for the system by creating the root
        # node and adding the generated subnodes of all children.
        # When a child needs to add multiple nodes, this is done by also
        # creating a node called '/' which will then be merged with the
        # root instead of appended.

        def generateMemNode(mem_range):
            node = FdtNode(f"memory@{int(mem_range.start):x}")
            node.append(FdtPropertyStrings("device_type", ["memory"]))
            node.append(
                FdtPropertyWords(
                    "reg",
                    state.addrCells(mem_range.start)
                    + state.sizeCells(mem_range.size()),
                )
            )
            return node

        root = FdtNode("/")
        root.append(state.addrCellsProperty())
        root.append(state.sizeCellsProperty())

        # Add memory nodes
        for mem_range in self.mem_ranges:
            root.append(generateMemNode(mem_range))

        for node in self.recurseDeviceTree(state):
            # Merge root nodes instead of adding them (for children
            # that need to add multiple root level nodes)
            if node.get_name() == root.get_name():
                root.merge(node)
            else:
                root.append(node)

        return root