/**************************************************************************************
* Copyright (c) 2020 Institute of Computing Technology, CAS
* Copyright (c) 2020 University of Chinese Academy of Sciences
*
* NutShell is licensed under Mulan PSL v2.
* You can use this software according to the terms and conditions of the Mulan PSL v2.
* You may obtain a copy of Mulan PSL v2 at:
*             http://license.coscl.org.cn/MulanPSL2
*
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR
* FIT FOR A PARTICULAR PURPOSE.
*
* See the Mulan PSL v2 for more details.
***************************************************************************************/

package sim

import bus.axi4._
import chisel3._
import device.AXI4RAM
import difftest._
import difftest.fpga.DifftestMemCtrl
import nutcore.NutCoreConfig
import system._

class NutShellSim extends Module with HasDiffTestInterfaces {
  lazy val config = NutCoreConfig(FPGAPlatform = false)
  val soc = Module(new NutShell()(config))
  val mem = Module(new AXI4RAM(memByte = 2L * 1024 * 1024 * 1024, useBlackBox = true))
  // Be careful with the commit checking of emu.
  // A large delay will make emu incorrectly report getting stuck.
  val memdelay = Module(new AXI4Delayer(0))
  val mmio = Module(new SimMMIO)

  soc.io.frontend <> mmio.io.dma

  memdelay.io.in <> soc.io.mem
  mem.io.in <> memdelay.io.out

  mmio.io.rw <> soc.io.mmio

  soc.io.meip := mmio.io.meip

  override def cpuName: Option[String] = Some("NutShell")
  val memIO = Option.when(DifftestModule.isFPGA) {
    DifftestMemCtrl.exposeIO(memdelay.io.out, mem.io.in)
  }
  override def difftestMemIO: Option[DifftestMemIO] = memIO

  val uart = IO(new UARTIO)
  uart <> mmio.io.uart
  override def connectTopIOs(difftest: DifftestTopIO): Unit = {
    difftest.uart <> uart
  }
}
