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from m5.objects.Device import BasicPioDevice
from m5.objects.IntPin import IntSinkPin
from m5.params import *
from m5.proxy import *
from m5.util.fdthelper import *

class Clint(BasicPioDevice):
    """
    This implementation of CLINT is based on
    the SiFive U54MC datasheet:
    https://sifive.cdn.prismic.io/sifive/fab000f6-
    0e07-48d0-9602-e437d5367806_sifive_U54MC_rtl_
    full_20G1.03.00_manual.pdf
    """
    type = 'Clint'
    cxx_header = 'dev/riscv/clint.hh'
    cxx_class = 'gem5::Clint'
    int_pin = IntSinkPin('Pin to receive RTC signal')
    pio_size = Param.Addr(0xC000, "PIO Size")
    num_threads = Param.Int("Number of threads in the system.")

    def generateDeviceTree(self, state):
        node = self.generateBasicPioDeviceNode(state, "clint", self.pio_addr,
                                               self.pio_size)

        cpus = self.system.unproxy(self).cpu
        int_extended = list()
        for cpu in cpus:
            phandle = state.phandle(cpu)
            int_extended.append(phandle)
            int_extended.append(0x3)
            int_extended.append(phandle)
            int_extended.append(0x7)

        node.append(FdtPropertyWords("interrupts-extended", int_extended))
        node.appendCompatible(["riscv,clint0"])

        yield node