xref: /gem5/src/dev/net/ns_gige.cc

/*
 * Copyright (c) 2004 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/* @file
 * Device module for modelling the National Semiconductor
 * DP83820 ethernet controller.  Does not support priority queueing
 */
#include <cstdio>
#include <deque>
#include <string>

#include "base/inet.hh"
#include "cpu/exec_context.hh"
#include "cpu/intr_control.hh"
#include "dev/dma.hh"
#include "dev/ns_gige.hh"
#include "dev/etherlink.hh"
#include "mem/bus/bus.hh"
#include "mem/bus/dma_interface.hh"
#include "mem/bus/pio_interface.hh"
#include "mem/bus/pio_interface_impl.hh"
#include "mem/functional_mem/memory_control.hh"
#include "mem/functional_mem/physical_memory.hh"
#include "sim/builder.hh"
#include "sim/host.hh"
#include "sim/sim_stats.hh"
#include "targetarch/vtophys.hh"
#include "dev/pciconfigall.hh"
#include "dev/tsunami_cchip.hh"

const char *NsRxStateStrings[] =
{
    "rxIdle",
    "rxDescRefr",
    "rxDescRead",
    "rxFifoBlock",
    "rxFragWrite",
    "rxDescWrite",
    "rxAdvance"
};

const char *NsTxStateStrings[] =
{
    "txIdle",
    "txDescRefr",
    "txDescRead",
    "txFifoBlock",
    "txFragRead",
    "txDescWrite",
    "txAdvance"
};

const char *NsDmaState[] =
{
    "dmaIdle",
    "dmaReading",
    "dmaWriting",
    "dmaReadWaiting",
    "dmaWriteWaiting"
};

using namespace std;

//helper function declarations
//These functions reverse Endianness so we can evaluate network data correctly
uint16_t reverseEnd16(uint16_t);
uint32_t reverseEnd32(uint32_t);

///////////////////////////////////////////////////////////////////////
//
// NSGigE PCI Device
//
NSGigE::NSGigE(const std::string &name, IntrControl *i, Tick intr_delay,
             PhysicalMemory *pmem, Tick tx_delay, Tick rx_delay,
             MemoryController *mmu, HierParams *hier, Bus *header_bus,
             Bus *payload_bus, Tick pio_latency, bool dma_desc_free,
             bool dma_data_free, Tick dma_read_delay, Tick dma_write_delay,
             Tick dma_read_factor, Tick dma_write_factor, PciConfigAll *cf,
             PciConfigData *cd, Tsunami *t, uint32_t bus, uint32_t dev,
             uint32_t func, bool rx_filter, const int eaddr[6])
    : PciDev(name, mmu, cf, cd, bus, dev, func), tsunami(t), ioEnable(false),
      txPacket(0), rxPacket(0), txPacketBufPtr(NULL), rxPacketBufPtr(NULL),
      txXferLen(0), rxXferLen(0), txState(txIdle), CTDD(false),
      txFifoAvail(MAX_TX_FIFO_SIZE), txHalt(false),
      txFragPtr(0), txDescCnt(0), txDmaState(dmaIdle), rxState(rxIdle),
      CRDD(false), rxPktBytes(0), rxFifoCnt(0), rxHalt(false),
      rxFragPtr(0), rxDescCnt(0), rxDmaState(dmaIdle), extstsEnable(false),
      rxDmaReadEvent(this), rxDmaWriteEvent(this),
      txDmaReadEvent(this), txDmaWriteEvent(this),
      dmaDescFree(dma_desc_free), dmaDataFree(dma_data_free),
      txDelay(tx_delay), rxDelay(rx_delay), rxKickTick(0), txKickTick(0),
      txEvent(this), rxFilterEnable(rx_filter), acceptBroadcast(false),
      acceptMulticast(false), acceptUnicast(false),
      acceptPerfect(false), acceptArp(false),
      physmem(pmem), intctrl(i), intrTick(0), cpuPendingIntr(false),
      intrEvent(0), interface(0), pioLatency(pio_latency)
{
    tsunami->ethernet = this;

    if (header_bus) {
        pioInterface = newPioInterface(name, hier, header_bus, this,
                                       &NSGigE::cacheAccess);

        if (payload_bus)
            dmaInterface = new DMAInterface<Bus>(name + ".dma",
                                                 header_bus, payload_bus, 1);
        else
            dmaInterface = new DMAInterface<Bus>(name + ".dma",
                                                 header_bus, header_bus, 1);
    } else if (payload_bus) {
        pioInterface = newPioInterface(name, hier, payload_bus, this,
                                       &NSGigE::cacheAccess);

        dmaInterface = new DMAInterface<Bus>(name + ".dma", payload_bus,
                                         payload_bus, 1);

    }


    intrDelay = US2Ticks(intr_delay);
    dmaReadDelay = dma_read_delay;
    dmaWriteDelay = dma_write_delay;
    dmaReadFactor = dma_read_factor;
    dmaWriteFactor = dma_write_factor;

    regsReset();
    rom.perfectMatch[0] = eaddr[0];
    rom.perfectMatch[1] = eaddr[1];
    rom.perfectMatch[2] = eaddr[2];
    rom.perfectMatch[3] = eaddr[3];
    rom.perfectMatch[4] = eaddr[4];
    rom.perfectMatch[5] = eaddr[5];
}

NSGigE::~NSGigE()
{}

void
NSGigE::regStats()
{
    txBytes
        .name(name() + ".txBytes")
        .desc("Bytes Transmitted")
        .prereq(txBytes)
        ;

    rxBytes
        .name(name() + ".rxBytes")
        .desc("Bytes Received")
        .prereq(rxBytes)
        ;

    txPackets
        .name(name() + ".txPackets")
        .desc("Number of Packets Transmitted")
        .prereq(txBytes)
        ;

    rxPackets
        .name(name() + ".rxPackets")
        .desc("Number of Packets Received")
        .prereq(rxBytes)
        ;

    txIPChecksums
        .name(name() + ".txIPChecksums")
        .desc("Number of tx IP Checksums done by device")
        .precision(0)
        .prereq(txBytes)
        ;

    rxIPChecksums
        .name(name() + ".rxIPChecksums")
        .desc("Number of rx IP Checksums done by device")
        .precision(0)
        .prereq(rxBytes)
        ;

    txTCPChecksums
        .name(name() + ".txTCPChecksums")
        .desc("Number of tx TCP Checksums done by device")
        .precision(0)
        .prereq(txBytes)
        ;

    rxTCPChecksums
        .name(name() + ".rxTCPChecksums")
        .desc("Number of rx TCP Checksums done by device")
        .precision(0)
        .prereq(rxBytes)
        ;

    descDmaReads
        .name(name() + ".descDMAReads")
        .desc("Number of descriptors the device read w/ DMA")
        .precision(0)
        ;

    descDmaWrites
        .name(name() + ".descDMAWrites")
        .desc("Number of descriptors the device wrote w/ DMA")
        .precision(0)
        ;

    descDmaRdBytes
        .name(name() + ".descDmaReadBytes")
        .desc("number of descriptor bytes read w/ DMA")
        .precision(0)
        ;

   descDmaWrBytes
        .name(name() + ".descDmaWriteBytes")
        .desc("number of descriptor bytes write w/ DMA")
        .precision(0)
        ;


    txBandwidth
        .name(name() + ".txBandwidth")
        .desc("Transmit Bandwidth (bits/s)")
        .precision(0)
        .prereq(txBytes)
        ;

    rxBandwidth
        .name(name() + ".rxBandwidth")
        .desc("Receive Bandwidth (bits/s)")
        .precision(0)
        .prereq(rxBytes)
        ;

    txPacketRate
        .name(name() + ".txPPS")
        .desc("Packet Tranmission Rate (packets/s)")
        .precision(0)
        .prereq(txBytes)
        ;

    rxPacketRate
        .name(name() + ".rxPPS")
        .desc("Packet Reception Rate (packets/s)")
        .precision(0)
        .prereq(rxBytes)
        ;

    txBandwidth = txBytes * Stats::constant(8) / simSeconds;
    rxBandwidth = rxBytes * Stats::constant(8) / simSeconds;
    txPacketRate = txPackets / simSeconds;
    rxPacketRate = rxPackets / simSeconds;
}

/**
 * This is to read the PCI general configuration registers
 */
void
NSGigE::ReadConfig(int offset, int size, uint8_t *data)
{
    if (offset < PCI_DEVICE_SPECIFIC)
        PciDev::ReadConfig(offset, size, data);
    else
        panic("Device specific PCI config space not implemented!\n");
}

/**
 * This is to write to the PCI general configuration registers
 */
void
NSGigE::WriteConfig(int offset, int size, uint32_t data)
{
    if (offset < PCI_DEVICE_SPECIFIC)
        PciDev::WriteConfig(offset, size, data);
    else
        panic("Device specific PCI config space not implemented!\n");

    // Need to catch writes to BARs to update the PIO interface
    switch (offset) {
        //seems to work fine without all these PCI settings, but i put in the IO
        //to double check, an assertion will fail if we need to properly
        // implement it
      case PCI_COMMAND:
        if (config.data[offset] & PCI_CMD_IOSE)
            ioEnable = true;
        else
            ioEnable = false;

#if 0
        if (config.data[offset] & PCI_CMD_BME) {
            bmEnabled = true;
        }
        else {
            bmEnabled = false;
        }

        if (config.data[offset] & PCI_CMD_MSE) {
            memEnable = true;
        }
        else {
            memEnable = false;
        }
#endif
        break;

      case PCI0_BASE_ADDR0:
        if (BARAddrs[0] != 0) {

            if (pioInterface)
                pioInterface->addAddrRange(BARAddrs[0], BARAddrs[0] + BARSize[0] - 1);

            BARAddrs[0] &= PA_UNCACHED_MASK;

        }
        break;
      case PCI0_BASE_ADDR1:
        if (BARAddrs[1] != 0) {

            if (pioInterface)
                pioInterface->addAddrRange(BARAddrs[1], BARAddrs[1] + BARSize[1] - 1);

            BARAddrs[1] &= PA_UNCACHED_MASK;

        }
        break;
    }
}

/**
 * This reads the device registers, which are detailed in the NS83820
 * spec sheet
 */
Fault
NSGigE::read(MemReqPtr &req, uint8_t *data)
{
    assert(ioEnable);

    //The mask is to give you only the offset into the device register file
    Addr daddr = req->paddr & 0xfff;
    DPRINTF(EthernetPIO, "read  da=%#x pa=%#x va=%#x size=%d\n",
            daddr, req->paddr, req->vaddr, req->size);


    //there are some reserved registers, you can see ns_gige_reg.h and
    //the spec sheet for details
    if (daddr > LAST && daddr <=  RESERVED) {
        panic("Accessing reserved register");
    } else if (daddr > RESERVED && daddr <= 0x3FC) {
        ReadConfig(daddr & 0xff, req->size, data);
        return No_Fault;
    } else if (daddr >= MIB_START && daddr <= MIB_END) {
        // don't implement all the MIB's.  hopefully the kernel
        // doesn't actually DEPEND upon their values
        // MIB are just hardware stats keepers
        uint32_t &reg = *(uint32_t *) data;
        reg = 0;
        return No_Fault;
    } else if (daddr > 0x3FC)
        panic("Something is messed up!\n");

    switch (req->size) {
      case sizeof(uint32_t):
        {
            uint32_t &reg = *(uint32_t *)data;

            switch (daddr) {
              case CR:
                reg = regs.command;
                //these are supposed to be cleared on a read
                reg &= ~(CR_RXD | CR_TXD | CR_TXR | CR_RXR);
                break;

              case CFG:
                reg = regs.config;
                break;

              case MEAR:
                reg = regs.mear;
                break;

              case PTSCR:
                reg = regs.ptscr;
                break;

              case ISR:
                reg = regs.isr;
                devIntrClear(ISR_ALL);
                break;

              case IMR:
                reg = regs.imr;
                break;

              case IER:
                reg = regs.ier;
                break;

              case IHR:
                reg = regs.ihr;
                break;

              case TXDP:
                reg = regs.txdp;
                break;

              case TXDP_HI:
                reg = regs.txdp_hi;
                break;

              case TXCFG:
                reg = regs.txcfg;
                break;

              case GPIOR:
                reg = regs.gpior;
                break;

              case RXDP:
                reg = regs.rxdp;
                break;

              case RXDP_HI:
                reg = regs.rxdp_hi;
                break;

              case RXCFG:
                reg = regs.rxcfg;
                break;

              case PQCR:
                reg = regs.pqcr;
                break;

              case WCSR:
                reg = regs.wcsr;
                break;

              case PCR:
                reg = regs.pcr;
                break;

                //see the spec sheet for how RFCR and RFDR work
                //basically, you write to RFCR to tell the machine what you want to do next
                //then you act upon RFDR, and the device will be prepared b/c
                //of what you wrote to RFCR
              case RFCR:
                reg = regs.rfcr;
                break;

              case RFDR:
                switch (regs.rfcr & RFCR_RFADDR) {
                  case 0x000:
                    reg = rom.perfectMatch[1];
                    reg = reg << 8;
                    reg += rom.perfectMatch[0];
                    break;
                  case 0x002:
                    reg = rom.perfectMatch[3] << 8;
                    reg += rom.perfectMatch[2];
                    break;
                  case 0x004:
                    reg = rom.perfectMatch[5] << 8;
                    reg += rom.perfectMatch[4];
                    break;
                  default:
                    panic("reading from RFDR for something for other than PMATCH!\n");
                    //didn't implement other RFDR functionality b/c driver didn't use
                }
                break;

              case SRR:
                reg = regs.srr;
                break;

              case MIBC:
                reg = regs.mibc;
                reg &= ~(MIBC_MIBS | MIBC_ACLR);
                break;

              case VRCR:
                reg = regs.vrcr;
                break;

              case VTCR:
                reg = regs.vtcr;
                break;

              case VDR:
                reg = regs.vdr;
                break;

              case CCSR:
                reg = regs.ccsr;
                break;

              case TBICR:
                reg = regs.tbicr;
                break;

              case TBISR:
                reg = regs.tbisr;
                break;

              case TANAR:
                reg = regs.tanar;
                break;

              case TANLPAR:
                reg = regs.tanlpar;
                break;

              case TANER:
                reg = regs.taner;
                break;

              case TESR:
                reg = regs.tesr;
                break;

              default:
                panic("reading unimplemented register: addr = %#x", daddr);
            }

            DPRINTF(EthernetPIO, "read from %#x: data=%d data=%#x\n",
                    daddr, reg, reg);
        }
        break;

      default:
        panic("accessing register with invalid size: addr=%#x, size=%d",
              daddr, req->size);
    }

    return No_Fault;
}

Fault
NSGigE::write(MemReqPtr &req, const uint8_t *data)
{
    assert(ioEnable);

    Addr daddr = req->paddr & 0xfff;
    DPRINTF(EthernetPIO, "write da=%#x pa=%#x va=%#x size=%d\n",
            daddr, req->paddr, req->vaddr, req->size);

    if (daddr > LAST && daddr <=  RESERVED) {
        panic("Accessing reserved register");
    } else if (daddr > RESERVED && daddr <= 0x3FC) {
        WriteConfig(daddr & 0xff, req->size, *(uint32_t *)data);
        return No_Fault;
    } else if (daddr > 0x3FC)
        panic("Something is messed up!\n");

    if (req->size == sizeof(uint32_t)) {
        uint32_t reg = *(uint32_t *)data;
        DPRINTF(EthernetPIO, "write data=%d data=%#x\n", reg, reg);

        switch (daddr) {
          case CR:
            regs.command = reg;
            if ((reg & (CR_TXE | CR_TXD)) == (CR_TXE | CR_TXD)) {
                txHalt = true;
            } else if (reg & CR_TXE) {
                //the kernel is enabling the transmit machine
                if (txState == txIdle)
                    txKick();
            } else if (reg & CR_TXD) {
                txHalt = true;
            }

            if ((reg & (CR_RXE | CR_RXD)) == (CR_RXE | CR_RXD)) {
                rxHalt = true;
            } else if (reg & CR_RXE) {
                if (rxState == rxIdle) {
                    rxKick();
                }
            } else if (reg & CR_RXD) {
                rxHalt = true;
            }

            if (reg & CR_TXR)
                txReset();

            if (reg & CR_RXR)
                rxReset();

            if (reg & CR_SWI)
                devIntrPost(ISR_SWI);

            if (reg & CR_RST) {
                txReset();
                rxReset();

                regsReset();
            }
            break;

          case CFG:
            if (reg & CFG_LNKSTS || reg & CFG_SPDSTS || reg & CFG_DUPSTS
                || reg & CFG_RESERVED || reg & CFG_T64ADDR
                || reg & CFG_PCI64_DET)
                panic("writing to read-only or reserved CFG bits!\n");

            regs.config |= reg & ~(CFG_LNKSTS | CFG_SPDSTS | CFG_DUPSTS | CFG_RESERVED |
                                  CFG_T64ADDR | CFG_PCI64_DET);

// all these #if 0's are because i don't THINK the kernel needs to have these implemented
// if there is a problem relating to one of these, you may need to add functionality in
#if 0
              if (reg & CFG_TBI_EN) ;
              if (reg & CFG_MODE_1000) ;
#endif

            if (reg & CFG_AUTO_1000)
                panic("CFG_AUTO_1000 not implemented!\n");

#if 0
            if (reg & CFG_PINT_DUPSTS || reg & CFG_PINT_LNKSTS || reg & CFG_PINT_SPDSTS) ;
            if (reg & CFG_TMRTEST) ;
            if (reg & CFG_MRM_DIS) ;
            if (reg & CFG_MWI_DIS) ;

            if (reg & CFG_T64ADDR)
                panic("CFG_T64ADDR is read only register!\n");

            if (reg & CFG_PCI64_DET)
                panic("CFG_PCI64_DET is read only register!\n");

            if (reg & CFG_DATA64_EN) ;
            if (reg & CFG_M64ADDR) ;
            if (reg & CFG_PHY_RST) ;
            if (reg & CFG_PHY_DIS) ;
#endif

            if (reg & CFG_EXTSTS_EN)
                extstsEnable = true;
            else
                extstsEnable = false;

#if 0
              if (reg & CFG_REQALG) ;
              if (reg & CFG_SB) ;
              if (reg & CFG_POW) ;
              if (reg & CFG_EXD) ;
              if (reg & CFG_PESEL) ;
              if (reg & CFG_BROM_DIS) ;
              if (reg & CFG_EXT_125) ;
              if (reg & CFG_BEM) ;
#endif
            break;

          case MEAR:
            regs.mear = reg;
            /* since phy is completely faked, MEAR_MD* don't matter
               and since the driver never uses MEAR_EE*, they don't matter */
#if 0
            if (reg & MEAR_EEDI) ;
            if (reg & MEAR_EEDO) ; //this one is read only
            if (reg & MEAR_EECLK) ;
            if (reg & MEAR_EESEL) ;
            if (reg & MEAR_MDIO) ;
            if (reg & MEAR_MDDIR) ;
            if (reg & MEAR_MDC) ;
#endif
            break;

          case PTSCR:
            regs.ptscr = reg & ~(PTSCR_RBIST_RDONLY);
            /* these control BISTs for various parts of chip - we don't care or do
               just fake that the BIST is done */
            if (reg & PTSCR_RBIST_EN)
                regs.ptscr |= PTSCR_RBIST_DONE;
            if (reg & PTSCR_EEBIST_EN)
                regs.ptscr &= ~PTSCR_EEBIST_EN;
            if (reg & PTSCR_EELOAD_EN)
                regs.ptscr &= ~PTSCR_EELOAD_EN;
            break;

          case ISR: /* writing to the ISR has no effect */
            panic("ISR is a read only register!\n");

          case IMR:
            regs.imr = reg;
            devIntrChangeMask();
            break;

          case IER:
            regs.ier = reg;
            break;

          case IHR:
            regs.ihr = reg;
            /* not going to implement real interrupt holdoff */
            break;

          case TXDP:
            regs.txdp = (reg & 0xFFFFFFFC);
            assert(txState == txIdle);
            CTDD = false;
            break;

          case TXDP_HI:
            regs.txdp_hi = reg;
            break;

          case TXCFG:
            regs.txcfg = reg;
#if 0
            if (reg & TXCFG_CSI) ;
            if (reg & TXCFG_HBI) ;
            if (reg & TXCFG_MLB) ;
            if (reg & TXCFG_ATP) ;
            if (reg & TXCFG_ECRETRY) ;  /* this could easily be implemented, but
                                           considering the network is just a fake
                                           pipe, wouldn't make sense to do this */

            if (reg & TXCFG_BRST_DIS) ;
#endif


            /* we handle our own DMA, ignore the kernel's exhortations */
            //if (reg & TXCFG_MXDMA) ;

            //also, we currently don't care about fill/drain thresholds
            //though this may change in the future with more realistic
            //networks or a driver which changes it according to feedback

            break;

          case GPIOR:
            regs.gpior = reg;
            /* these just control general purpose i/o pins, don't matter */
            break;

          case RXDP:
            regs.rxdp = reg;
            break;

          case RXDP_HI:
            regs.rxdp_hi = reg;
            break;

          case RXCFG:
            regs.rxcfg = reg;
#if 0
            if (reg & RXCFG_AEP) ;
            if (reg & RXCFG_ARP) ;
            if (reg & RXCFG_STRIPCRC) ;
            if (reg & RXCFG_RX_RD) ;
            if (reg & RXCFG_ALP) ;
            if (reg & RXCFG_AIRL) ;
#endif

            /* we handle our own DMA, ignore what kernel says about it */
            //if (reg & RXCFG_MXDMA) ;

#if 0
            //also, we currently don't care about fill/drain thresholds
            //though this may change in the future with more realistic
            //networks or a driver which changes it according to feedback
            if (reg & (RXCFG_DRTH | RXCFG_DRTH0)) ;
#endif
            break;

          case PQCR:
            /* there is no priority queueing used in the linux 2.6 driver */
            regs.pqcr = reg;
            break;

          case WCSR:
            /* not going to implement wake on LAN */
            regs.wcsr = reg;
            break;

          case PCR:
            /* not going to implement pause control */
            regs.pcr = reg;
            break;

          case RFCR:
            regs.rfcr = reg;

            rxFilterEnable = (reg & RFCR_RFEN) ? true : false;
            acceptBroadcast = (reg & RFCR_AAB) ? true : false;
            acceptMulticast = (reg & RFCR_AAM) ? true : false;
            acceptUnicast = (reg & RFCR_AAU) ? true : false;
            acceptPerfect = (reg & RFCR_APM) ? true : false;
            acceptArp = (reg & RFCR_AARP) ? true : false;

            if (reg & RFCR_APAT) ;
//                panic("RFCR_APAT not implemented!\n");

            if (reg & RFCR_MHEN || reg & RFCR_UHEN)
                panic("hash filtering not implemented!\n");

            if (reg & RFCR_ULM)
                panic("RFCR_ULM not implemented!\n");

            break;

          case RFDR:
            panic("the driver never writes to RFDR, something is wrong!\n");

          case BRAR:
            panic("the driver never uses BRAR, something is wrong!\n");

          case BRDR:
            panic("the driver never uses BRDR, something is wrong!\n");

          case SRR:
            panic("SRR is read only register!\n");

          case MIBC:
            panic("the driver never uses MIBC, something is wrong!\n");

          case VRCR:
            regs.vrcr = reg;
            break;

          case VTCR:
            regs.vtcr = reg;
            break;

          case VDR:
            panic("the driver never uses VDR, something is wrong!\n");
            break;

          case CCSR:
            /* not going to implement clockrun stuff */
            regs.ccsr = reg;
            break;

          case TBICR:
            regs.tbicr = reg;
            if (reg & TBICR_MR_LOOPBACK)
                panic("TBICR_MR_LOOPBACK never used, something wrong!\n");

            if (reg & TBICR_MR_AN_ENABLE) {
                regs.tanlpar = regs.tanar;
                regs.tbisr |= (TBISR_MR_AN_COMPLETE | TBISR_MR_LINK_STATUS);
            }

#if 0
            if (reg & TBICR_MR_RESTART_AN) ;
#endif

            break;

          case TBISR:
            panic("TBISR is read only register!\n");

          case TANAR:
            regs.tanar = reg;
            if (reg & TANAR_PS2)
                panic("this isn't used in driver, something wrong!\n");

            if (reg & TANAR_PS1)
                panic("this isn't used in driver, something wrong!\n");
            break;

          case TANLPAR:
            panic("this should only be written to by the fake phy!\n");

          case TANER:
            panic("TANER is read only register!\n");

          case TESR:
            regs.tesr = reg;
            break;

          default:
            panic("thought i covered all the register, what is this? addr=%#x",
                  daddr);
        }
    } else
        panic("Invalid Request Size");

    return No_Fault;
}

void
NSGigE::devIntrPost(uint32_t interrupts)
{
    bool delay = false;

    if (interrupts & ISR_RESERVE)
        panic("Cannot set a reserved interrupt");

    if (interrupts & ISR_TXRCMP)
        regs.isr |= ISR_TXRCMP;

    if (interrupts & ISR_RXRCMP)
        regs.isr |= ISR_RXRCMP;

//ISR_DPERR  not implemented
//ISR_SSERR not implemented
//ISR_RMABT not implemented
//ISR_RXSOVR not implemented
//ISR_HIBINT not implemented
//ISR_PHY not implemented
//ISR_PME not implemented

    if (interrupts & ISR_SWI)
        regs.isr |= ISR_SWI;

//ISR_MIB not implemented
//ISR_TXURN not implemented

    if (interrupts & ISR_TXIDLE)
        regs.isr |= ISR_TXIDLE;

    if (interrupts & ISR_TXERR)
        regs.isr |= ISR_TXERR;

    if (interrupts & ISR_TXDESC)
        regs.isr |= ISR_TXDESC;

    if (interrupts & ISR_TXOK) {
        regs.isr |= ISR_TXOK;
        delay = true;
    }

    if (interrupts & ISR_RXORN)
        regs.isr |= ISR_RXORN;

    if (interrupts & ISR_RXIDLE)
        regs.isr |= ISR_RXIDLE;

//ISR_RXEARLY not implemented

    if (interrupts & ISR_RXERR)
        regs.isr |= ISR_RXERR;

    if (interrupts & ISR_RXDESC)
        regs.isr |= ISR_RXDESC;

    if (interrupts & ISR_RXOK) {
        delay = true;
        regs.isr |= ISR_RXOK;
    }

    if ((regs.isr & regs.imr)) {
        Tick when = curTick;
        if (delay)
            when += intrDelay;
        cpuIntrPost(when);
    }

    DPRINTF(EthernetIntr, "**interrupt written to ISR: intr=%#x isr=%#x imr=%#x\n",
            interrupts, regs.isr, regs.imr);
}

void
NSGigE::devIntrClear(uint32_t interrupts)
{
    if (interrupts & ISR_RESERVE)
        panic("Cannot clear a reserved interrupt");

    if (interrupts & ISR_TXRCMP)
        regs.isr &= ~ISR_TXRCMP;

    if (interrupts & ISR_RXRCMP)
        regs.isr &= ~ISR_RXRCMP;

//ISR_DPERR  not implemented
//ISR_SSERR not implemented
//ISR_RMABT not implemented
//ISR_RXSOVR not implemented
//ISR_HIBINT not implemented
//ISR_PHY not implemented
//ISR_PME not implemented

    if (interrupts & ISR_SWI)
        regs.isr &= ~ISR_SWI;

//ISR_MIB not implemented
//ISR_TXURN not implemented

    if (interrupts & ISR_TXIDLE)
        regs.isr &= ~ISR_TXIDLE;

    if (interrupts & ISR_TXERR)
        regs.isr &= ~ISR_TXERR;

    if (interrupts & ISR_TXDESC)
        regs.isr &= ~ISR_TXDESC;

    if (interrupts & ISR_TXOK)
        regs.isr &= ~ISR_TXOK;

    if (interrupts & ISR_RXORN)
        regs.isr &= ~ISR_RXORN;

    if (interrupts & ISR_RXIDLE)
        regs.isr &= ~ISR_RXIDLE;

//ISR_RXEARLY not implemented

    if (interrupts & ISR_RXERR)
        regs.isr &= ~ISR_RXERR;

    if (interrupts & ISR_RXDESC)
        regs.isr &= ~ISR_RXDESC;

    if (interrupts & ISR_RXOK)
        regs.isr &= ~ISR_RXOK;

    if (!(regs.isr & regs.imr))
        cpuIntrClear();

    DPRINTF(EthernetIntr, "**interrupt cleared from ISR: intr=%x isr=%x imr=%x\n",
            interrupts, regs.isr, regs.imr);
}

void
NSGigE::devIntrChangeMask()
{
    DPRINTF(EthernetIntr, "interrupt mask changed\n");

    if (regs.isr & regs.imr)
        cpuIntrPost(curTick);
    else
        cpuIntrClear();
}

void
NSGigE::cpuIntrPost(Tick when)
{
    //If the interrupt you want to post is later than an
    //interrupt already scheduled, just let it post in the coming one and
    //don't schedule another.
    //HOWEVER, must be sure that the scheduled intrTick is in the future
    //(this was formerly the source of a bug)
    assert((intrTick >= curTick) || (intrTick == 0));
    if (when > intrTick && intrTick != 0)
        return;

    intrTick = when;

    if (intrEvent) {
        intrEvent->squash();
        intrEvent = 0;
    }

    if (when < curTick) {
        cpuInterrupt();
    } else {
        DPRINTF(EthernetIntr, "going to schedule an interrupt for intrTick=%d\n",
                intrTick);
        intrEvent = new IntrEvent(this, true);
        intrEvent->schedule(intrTick);
    }
}

void
NSGigE::cpuInterrupt()
{
    // Don't send an interrupt if there's already one
    if (cpuPendingIntr) {
        DPRINTF(EthernetIntr,
                "would send an interrupt now, but there's already pending\n");
        intrTick = 0;
        return;
    }
    // Don't send an interrupt if it's supposed to be delayed
    if (intrTick > curTick) {
        DPRINTF(EthernetIntr, "an interrupt is scheduled for %d, wait til then\n",
                intrTick);
        return;
    }

    // Whether or not there's a pending interrupt, we don't care about
    // it anymore
    intrEvent = 0;
    intrTick = 0;

    // Send interrupt
    cpuPendingIntr = true;
    /** @todo rework the intctrl to be tsunami ok */
    //intctrl->post(TheISA::INTLEVEL_IRQ1, TheISA::INTINDEX_ETHERNET);
    DPRINTF(EthernetIntr, "Posting interrupts to cchip!\n");
    tsunami->cchip->postDRIR(configData->config.hdr.pci0.interruptLine);
}

void
NSGigE::cpuIntrClear()
{
    if (cpuPendingIntr) {
        cpuPendingIntr = false;
        /** @todo rework the intctrl to be tsunami ok */
        //intctrl->clear(TheISA::INTLEVEL_IRQ1, TheISA::INTINDEX_ETHERNET);
        DPRINTF(EthernetIntr, "clearing all interrupts from cchip\n");
        tsunami->cchip->clearDRIR(configData->config.hdr.pci0.interruptLine);
    }
}

bool
NSGigE::cpuIntrPending() const
{ return cpuPendingIntr; }

void
NSGigE::txReset()
{

    DPRINTF(Ethernet, "transmit reset\n");

    CTDD = false;
    txFifoAvail = MAX_TX_FIFO_SIZE;
    txHalt = false;
    txFragPtr = 0;
    assert(txDescCnt == 0);
    txFifo.clear();
    regs.command &= ~CR_TXE;
    txState = txIdle;
    assert(txDmaState == dmaIdle);
}

void
NSGigE::rxReset()
{
    DPRINTF(Ethernet, "receive reset\n");

    CRDD = false;
    assert(rxPktBytes == 0);
    rxFifoCnt = 0;
    rxHalt = false;
    rxFragPtr = 0;
    assert(rxDescCnt == 0);
    assert(rxDmaState == dmaIdle);
    rxFifo.clear();
    regs.command &= ~CR_RXE;
    rxState = rxIdle;
}

void NSGigE::regsReset()
{
    memset(&regs, 0, sizeof(regs));
    regs.config = 0x80000000;
    regs.mear = 0x12;
    regs.isr = 0x00608000;
    regs.txcfg = 0x120;
    regs.rxcfg = 0x4;
    regs.srr = 0x0103;
    regs.mibc = 0x2;
    regs.vdr = 0x81;
    regs.tesr = 0xc000;

    extstsEnable = false;
    acceptBroadcast = false;
    acceptMulticast = false;
    acceptUnicast = false;
    acceptPerfect = false;
    acceptArp = false;
}

void
NSGigE::rxDmaReadCopy()
{
    assert(rxDmaState == dmaReading);

    memcpy(rxDmaData, physmem->dma_addr(rxDmaAddr, rxDmaLen), rxDmaLen);
    rxDmaState = dmaIdle;

    DPRINTF(EthernetDMA, "rx dma read  paddr=%#x len=%d\n",
            rxDmaAddr, rxDmaLen);
    DDUMP(EthernetDMA, rxDmaData, rxDmaLen);
}

bool
NSGigE::doRxDmaRead()
{
    assert(rxDmaState == dmaIdle || rxDmaState == dmaReadWaiting);
    rxDmaState = dmaReading;

    if (dmaInterface && !rxDmaFree) {
        if (dmaInterface->busy())
            rxDmaState = dmaReadWaiting;
        else
            dmaInterface->doDMA(Read, rxDmaAddr, rxDmaLen, curTick,
                                &rxDmaReadEvent, true);
        return true;
    }

    if (dmaReadDelay == 0 && dmaReadFactor == 0) {
        rxDmaReadCopy();
        return false;
    }

    Tick factor = ((rxDmaLen + ULL(63)) >> ULL(6)) * dmaReadFactor;
    Tick start = curTick + dmaReadDelay + factor;
    rxDmaReadEvent.schedule(start);
    return true;
}

void
NSGigE::rxDmaReadDone()
{
    assert(rxDmaState == dmaReading);
    rxDmaReadCopy();

    // If the transmit state machine has a pending DMA, let it go first
    if (txDmaState == dmaReadWaiting || txDmaState == dmaWriteWaiting)
        txKick();

    rxKick();
}

void
NSGigE::rxDmaWriteCopy()
{
    assert(rxDmaState == dmaWriting);

    memcpy(physmem->dma_addr(rxDmaAddr, rxDmaLen), rxDmaData, rxDmaLen);
    rxDmaState = dmaIdle;

    DPRINTF(EthernetDMA, "rx dma write paddr=%#x len=%d\n",
            rxDmaAddr, rxDmaLen);
    DDUMP(EthernetDMA, rxDmaData, rxDmaLen);
}

bool
NSGigE::doRxDmaWrite()
{
    assert(rxDmaState == dmaIdle || rxDmaState == dmaWriteWaiting);
    rxDmaState = dmaWriting;

    if (dmaInterface && !rxDmaFree) {
        if (dmaInterface->busy())
            rxDmaState = dmaWriteWaiting;
        else
            dmaInterface->doDMA(WriteInvalidate, rxDmaAddr, rxDmaLen, curTick,
                                &rxDmaWriteEvent, true);
        return true;
    }

    if (dmaWriteDelay == 0 && dmaWriteFactor == 0) {
        rxDmaWriteCopy();
        return false;
    }

    Tick factor = ((rxDmaLen + ULL(63)) >> ULL(6)) * dmaWriteFactor;
    Tick start = curTick + dmaWriteDelay + factor;
    rxDmaWriteEvent.schedule(start);
    return true;
}

void
NSGigE::rxDmaWriteDone()
{
    assert(rxDmaState == dmaWriting);
    rxDmaWriteCopy();

    // If the transmit state machine has a pending DMA, let it go first
    if (txDmaState == dmaReadWaiting || txDmaState == dmaWriteWaiting)
        txKick();

    rxKick();
}

void
NSGigE::rxKick()
{
    DPRINTF(EthernetSM, "receive kick state=%s (rxBuf.size=%d)\n",
            NsRxStateStrings[rxState], rxFifo.size());

    if (rxKickTick > curTick) {
        DPRINTF(EthernetSM, "receive kick exiting, can't run till %d\n",
                rxKickTick);
        return;
    }

  next:
    switch(rxDmaState) {
      case dmaReadWaiting:
        if (doRxDmaRead())
            goto exit;
        break;
      case dmaWriteWaiting:
        if (doRxDmaWrite())
            goto exit;
        break;
      default:
        break;
    }

    // see state machine from spec for details
    // the way this works is, if you finish work on one state and can go directly to
    // another, you do that through jumping to the label "next".  however, if you have
    // intermediate work, like DMA so that you can't go to the next state yet, you go to
    // exit and exit the loop.  however, when the DMA is done it will trigger an
    // event and come back to this loop.
    switch (rxState) {
      case rxIdle:
        if (!regs.command & CR_RXE) {
            DPRINTF(EthernetSM, "Receive Disabled! Nothing to do.\n");
            goto exit;
        }

        if (CRDD) {
            rxState = rxDescRefr;

            rxDmaAddr = regs.rxdp & 0x3fffffff;
            rxDmaData = &rxDescCache + offsetof(ns_desc, link);
            rxDmaLen = sizeof(rxDescCache.link);
            rxDmaFree = dmaDescFree;

            descDmaReads++;
            descDmaRdBytes += rxDmaLen;

            if (doRxDmaRead())
                goto exit;
        } else {
            rxState = rxDescRead;

            rxDmaAddr = regs.rxdp & 0x3fffffff;
            rxDmaData = &rxDescCache;
            rxDmaLen = sizeof(ns_desc);
            rxDmaFree = dmaDescFree;

            descDmaReads++;
            descDmaRdBytes += rxDmaLen;

            if (doRxDmaRead())
                goto exit;
        }
        break;

      case rxDescRefr:
        if (rxDmaState != dmaIdle)
            goto exit;

        rxState = rxAdvance;
        break;

     case rxDescRead:
        if (rxDmaState != dmaIdle)
            goto exit;

        DPRINTF(EthernetDesc,
                "rxDescCache:\n\tlink=%08x\n\tbufptr=%08x\n\tcmdsts=%08x\n\textsts=%08x\n"
                ,rxDescCache.link, rxDescCache.bufptr, rxDescCache.cmdsts,
                rxDescCache.extsts);

        if (rxDescCache.cmdsts & CMDSTS_OWN) {
            rxState = rxIdle;
        } else {
            rxState = rxFifoBlock;
            rxFragPtr = rxDescCache.bufptr;
            rxDescCnt = rxDescCache.cmdsts & CMDSTS_LEN_MASK;
        }
        break;

      case rxFifoBlock:
        if (!rxPacket) {
            /**
             * @todo in reality, we should be able to start processing
             * the packet as it arrives, and not have to wait for the
             * full packet ot be in the receive fifo.
             */
            if (rxFifo.empty())
                goto exit;

            DPRINTF(EthernetSM, "\n\n*****processing receive of new packet\n");

            // If we don't have a packet, grab a new one from the fifo.
            rxPacket = rxFifo.front();
            rxPktBytes = rxPacket->length;
            rxPacketBufPtr = rxPacket->data;

            if (DTRACE(Ethernet)) {
                if (rxPacket->isIpPkt()) {
                    ip_header *ip = rxPacket->getIpHdr();
                    DPRINTF(Ethernet, "ID is %d\n", reverseEnd16(ip->ID));
                    if (rxPacket->isTcpPkt()) {
                        tcp_header *tcp = rxPacket->getTcpHdr(ip);
                        DPRINTF(Ethernet, "Src Port = %d, Dest Port = %d\n",
                                reverseEnd16(tcp->src_port_num),
                                reverseEnd16(tcp->dest_port_num));
                    }
                }
            }

            // sanity check - i think the driver behaves like this
            assert(rxDescCnt >= rxPktBytes);

            // Must clear the value before popping to decrement the
            // reference count
            rxFifo.front() = NULL;
            rxFifo.pop_front();
            rxFifoCnt -= rxPacket->length;
        }


        // dont' need the && rxDescCnt > 0 if driver sanity check above holds
        if (rxPktBytes > 0) {
            rxState = rxFragWrite;
            // don't need min<>(rxPktBytes,rxDescCnt) if above sanity check holds
            rxXferLen = rxPktBytes;

            rxDmaAddr = rxFragPtr & 0x3fffffff;
            rxDmaData = rxPacketBufPtr;
            rxDmaLen = rxXferLen;
            rxDmaFree = dmaDataFree;

            if (doRxDmaWrite())
                goto exit;

        } else {
            rxState = rxDescWrite;

            //if (rxPktBytes == 0) {  /* packet is done */
            assert(rxPktBytes == 0);
            DPRINTF(EthernetSM, "done with receiving packet\n");

            rxDescCache.cmdsts |= CMDSTS_OWN;
            rxDescCache.cmdsts &= ~CMDSTS_MORE;
            rxDescCache.cmdsts |= CMDSTS_OK;
            rxDescCache.cmdsts &= 0xffff0000;
            rxDescCache.cmdsts += rxPacket->length;   //i.e. set CMDSTS_SIZE

#if 0
            /* all the driver uses these are for its own stats keeping
               which we don't care about, aren't necessary for functionality
               and doing this would just slow us down.  if they end up using
               this in a later version for functional purposes, just undef
            */
            if (rxFilterEnable) {
                rxDescCache.cmdsts &= ~CMDSTS_DEST_MASK;
                if (rxFifo.front()->IsUnicast())
                    rxDescCache.cmdsts |= CMDSTS_DEST_SELF;
                if (rxFifo.front()->IsMulticast())
                    rxDescCache.cmdsts |= CMDSTS_DEST_MULTI;
                if (rxFifo.front()->IsBroadcast())
                    rxDescCache.cmdsts |= CMDSTS_DEST_MASK;
            }
#endif

            if (rxPacket->isIpPkt() && extstsEnable) {
                rxDescCache.extsts |= EXTSTS_IPPKT;
                rxIPChecksums++;
                if (!ipChecksum(rxPacket, false)) {
                    DPRINTF(EthernetCksum, "Rx IP Checksum Error\n");
                    rxDescCache.extsts |= EXTSTS_IPERR;
                }
                if (rxPacket->isTcpPkt()) {
                    rxDescCache.extsts |= EXTSTS_TCPPKT;
                    rxTCPChecksums++;
                    if (!tcpChecksum(rxPacket, false)) {
                        DPRINTF(EthernetCksum, "Rx TCP Checksum Error\n");
                        rxDescCache.extsts |= EXTSTS_TCPERR;

                    }
                } else if (rxPacket->isUdpPkt()) {
                    rxDescCache.extsts |= EXTSTS_UDPPKT;
                    if (!udpChecksum(rxPacket, false)) {
                        DPRINTF(EthernetCksum, "Rx UDP Checksum Error\n");
                        rxDescCache.extsts |= EXTSTS_UDPERR;
                    }
                }
            }
            rxPacket = 0;

            /* the driver seems to always receive into desc buffers
               of size 1514, so you never have a pkt that is split
               into multiple descriptors on the receive side, so
               i don't implement that case, hence the assert above.
            */

            DPRINTF(EthernetDesc, "rxDesc writeback:\n\tcmdsts=%08x\n\textsts=%08x\n",
                    rxDescCache.cmdsts, rxDescCache.extsts);

            rxDmaAddr = (regs.rxdp + offsetof(ns_desc, cmdsts)) & 0x3fffffff;
            rxDmaData = &(rxDescCache.cmdsts);
            rxDmaLen = sizeof(rxDescCache.cmdsts) + sizeof(rxDescCache.extsts);
            rxDmaFree = dmaDescFree;

            descDmaWrites++;
            descDmaWrBytes += rxDmaLen;

            if (doRxDmaWrite())
                goto exit;
        }
        break;

      case rxFragWrite:
        if (rxDmaState != dmaIdle)
            goto exit;

        rxPacketBufPtr += rxXferLen;
        rxFragPtr += rxXferLen;
        rxPktBytes -= rxXferLen;

        rxState = rxFifoBlock;
        break;

      case rxDescWrite:
        if (rxDmaState != dmaIdle)
            goto exit;

        assert(rxDescCache.cmdsts & CMDSTS_OWN);

        assert(rxPacket == 0);
        devIntrPost(ISR_RXOK);

        if (rxDescCache.cmdsts & CMDSTS_INTR)
            devIntrPost(ISR_RXDESC);

        if (rxHalt) {
            DPRINTF(EthernetSM, "Halting the RX state machine\n");
            rxState = rxIdle;
            rxHalt = false;
        } else
            rxState = rxAdvance;
        break;

      case rxAdvance:
        if (rxDescCache.link == 0) {
            rxState = rxIdle;
            return;
        } else {
            rxState = rxDescRead;
            regs.rxdp = rxDescCache.link;
            CRDD = false;

            rxDmaAddr = regs.rxdp & 0x3fffffff;
            rxDmaData = &rxDescCache;
            rxDmaLen = sizeof(ns_desc);
            rxDmaFree = dmaDescFree;

            if (doRxDmaRead())
                goto exit;
        }
        break;

      default:
        panic("Invalid rxState!");
    }


    DPRINTF(EthernetSM, "entering next rx state = %s\n",
            NsRxStateStrings[rxState]);

    if (rxState == rxIdle) {
        regs.command &= ~CR_RXE;
        devIntrPost(ISR_RXIDLE);
        return;
    }

    goto next;

  exit:
    /**
     * @todo do we want to schedule a future kick?
     */
    DPRINTF(EthernetSM, "rx state machine exited state=%s\n",
            NsRxStateStrings[rxState]);
}

void
NSGigE::transmit()
{
    if (txFifo.empty()) {
        DPRINTF(Ethernet, "nothing to transmit\n");
        return;
    }

    DPRINTF(Ethernet, "\n\nAttempt Pkt Transmit: txFifo length = %d\n",
            MAX_TX_FIFO_SIZE - txFifoAvail);
    if (interface->sendPacket(txFifo.front())) {
        if (DTRACE(Ethernet)) {
            if (txFifo.front()->isIpPkt()) {
                ip_header *ip = txFifo.front()->getIpHdr();
                DPRINTF(Ethernet, "ID is %d\n", reverseEnd16(ip->ID));
                if (txFifo.front()->isTcpPkt()) {
                    tcp_header *tcp = txFifo.front()->getTcpHdr(ip);
                    DPRINTF(Ethernet, "Src Port = %d, Dest Port = %d\n",
                            reverseEnd16(tcp->src_port_num),
                            reverseEnd16(tcp->dest_port_num));
                }
            }
        }

        DDUMP(Ethernet, txFifo.front()->data, txFifo.front()->length);
        txBytes += txFifo.front()->length;
        txPackets++;

        txFifoAvail += txFifo.front()->length;

        DPRINTF(Ethernet, "Successful Xmit! now txFifoAvail is %d\n", txFifoAvail);
        txFifo.front() = NULL;
        txFifo.pop_front();

        /* normally do a writeback of the descriptor here, and ONLY after that is
           done, send this interrupt.  but since our stuff never actually fails,
           just do this interrupt here, otherwise the code has to stray from this
           nice format.  besides, it's functionally the same.
        */
        devIntrPost(ISR_TXOK);
    } else
        DPRINTF(Ethernet, "May need to rethink always sending the descriptors back?\n");

   if (!txFifo.empty() && !txEvent.scheduled()) {
       DPRINTF(Ethernet, "reschedule transmit\n");
       txEvent.schedule(curTick + 1000);
   }
}

void
NSGigE::txDmaReadCopy()
{
    assert(txDmaState == dmaReading);

    memcpy(txDmaData, physmem->dma_addr(txDmaAddr, txDmaLen), txDmaLen);
    txDmaState = dmaIdle;

    DPRINTF(EthernetDMA, "tx dma read  paddr=%#x len=%d\n",
            txDmaAddr, txDmaLen);
    DDUMP(EthernetDMA, txDmaData, txDmaLen);
}

bool
NSGigE::doTxDmaRead()
{
    assert(txDmaState == dmaIdle || txDmaState == dmaReadWaiting);
    txDmaState = dmaReading;

    if (dmaInterface && !txDmaFree) {
        if (dmaInterface->busy())
            txDmaState = dmaReadWaiting;
        else
            dmaInterface->doDMA(Read, txDmaAddr, txDmaLen, curTick,
                                &txDmaReadEvent, true);
        return true;
    }

    if (dmaReadDelay == 0 && dmaReadFactor == 0.0) {
        txDmaReadCopy();
        return false;
    }

    Tick factor = ((txDmaLen + ULL(63)) >> ULL(6)) * dmaReadFactor;
    Tick start = curTick + dmaReadDelay + factor;
    txDmaReadEvent.schedule(start);
    return true;
}

void
NSGigE::txDmaReadDone()
{
    assert(txDmaState == dmaReading);
    txDmaReadCopy();

    // If the receive state machine  has a pending DMA, let it go first
    if (rxDmaState == dmaReadWaiting || rxDmaState == dmaWriteWaiting)
        rxKick();

    txKick();
}

void
NSGigE::txDmaWriteCopy()
{
    assert(txDmaState == dmaWriting);

    memcpy(physmem->dma_addr(txDmaAddr, txDmaLen), txDmaData, txDmaLen);
    txDmaState = dmaIdle;

    DPRINTF(EthernetDMA, "tx dma write paddr=%#x len=%d\n",
            txDmaAddr, txDmaLen);
    DDUMP(EthernetDMA, txDmaData, txDmaLen);
}

bool
NSGigE::doTxDmaWrite()
{
    assert(txDmaState == dmaIdle || txDmaState == dmaWriteWaiting);
    txDmaState = dmaWriting;

    if (dmaInterface && !txDmaFree) {
        if (dmaInterface->busy())
            txDmaState = dmaWriteWaiting;
        else
            dmaInterface->doDMA(WriteInvalidate, txDmaAddr, txDmaLen, curTick,
                                &txDmaWriteEvent, true);
        return true;
    }

    if (dmaWriteDelay == 0 && dmaWriteFactor == 0.0) {
        txDmaWriteCopy();
        return false;
    }

    Tick factor = ((txDmaLen + ULL(63)) >> ULL(6)) * dmaWriteFactor;
    Tick start = curTick + dmaWriteDelay + factor;
    txDmaWriteEvent.schedule(start);
    return true;
}

void
NSGigE::txDmaWriteDone()
{
    assert(txDmaState == dmaWriting);
    txDmaWriteCopy();

    // If the receive state machine  has a pending DMA, let it go first
    if (rxDmaState == dmaReadWaiting || rxDmaState == dmaWriteWaiting)
        rxKick();

    txKick();
}

void
NSGigE::txKick()
{
    DPRINTF(EthernetSM, "transmit kick state=%s\n", NsTxStateStrings[txState]);

    if (txKickTick > curTick) {
        DPRINTF(EthernetSM, "transmit kick exiting, can't run till %d\n",
                txKickTick);

        return;
    }

  next:
    switch(txDmaState) {
      case dmaReadWaiting:
        if (doTxDmaRead())
            goto exit;
        break;
      case dmaWriteWaiting:
        if (doTxDmaWrite())
            goto exit;
        break;
      default:
        break;
    }

    switch (txState) {
      case txIdle:
        if (!regs.command & CR_TXE) {
            DPRINTF(EthernetSM, "Transmit disabled.  Nothing to do.\n");
            goto exit;
        }

        if (CTDD) {
            txState = txDescRefr;

            txDmaAddr = regs.txdp & 0x3fffffff;
            txDmaData = &txDescCache + offsetof(ns_desc, link);
            txDmaLen = sizeof(txDescCache.link);
            txDmaFree = dmaDescFree;

            descDmaReads++;
            descDmaRdBytes += txDmaLen;

            if (doTxDmaRead())
                goto exit;

        } else {
            txState = txDescRead;

            txDmaAddr = regs.txdp & 0x3fffffff;
            txDmaData = &txDescCache;
            txDmaLen = sizeof(ns_desc);
            txDmaFree = dmaDescFree;

            descDmaReads++;
            descDmaRdBytes += txDmaLen;

            if (doTxDmaRead())
                goto exit;
        }
        break;

      case txDescRefr:
        if (txDmaState != dmaIdle)
            goto exit;

        txState = txAdvance;
        break;

      case txDescRead:
        if (txDmaState != dmaIdle)
            goto exit;

        DPRINTF(EthernetDesc,
                "txDescCache data:\n\tlink=%08x\n\tbufptr=%08x\n\tcmdsts=%08x\n\textsts=%08x\n"
                ,txDescCache.link, txDescCache.bufptr, txDescCache.cmdsts,
                txDescCache.extsts);

        if (txDescCache.cmdsts & CMDSTS_OWN) {
            txState = txFifoBlock;
            txFragPtr = txDescCache.bufptr;
            txDescCnt = txDescCache.cmdsts & CMDSTS_LEN_MASK;
        } else {
            txState = txIdle;
        }
        break;

      case txFifoBlock:
        if (!txPacket) {
            DPRINTF(EthernetSM, "\n\n*****starting the tx of a new packet\n");
            txPacket = new EtherPacket;
            txPacket->data = new uint8_t[16384];
            txPacketBufPtr = txPacket->data;
        }

        if (txDescCnt == 0) {
            DPRINTF(EthernetSM, "the txDescCnt == 0, done with descriptor\n");
            if (txDescCache.cmdsts & CMDSTS_MORE) {
                DPRINTF(EthernetSM, "there are more descriptors to come\n");
                txState = txDescWrite;

                txDescCache.cmdsts &= ~CMDSTS_OWN;

                txDmaAddr = (regs.txdp + offsetof(ns_desc, cmdsts)) & 0x3fffffff;
                txDmaData = &(txDescCache.cmdsts);
                txDmaLen = sizeof(txDescCache.cmdsts);
                txDmaFree = dmaDescFree;

                if (doTxDmaWrite())
                    goto exit;

            } else { /* this packet is totally done */
                DPRINTF(EthernetSM, "This packet is done, let's wrap it up\n");
                /* deal with the the packet that just finished */
                if ((regs.vtcr & VTCR_PPCHK) && extstsEnable) {
                    if (txDescCache.extsts & EXTSTS_UDPPKT) {
                        udpChecksum(txPacket, true);
                    } else if (txDescCache.extsts & EXTSTS_TCPPKT) {
                        tcpChecksum(txPacket, true);
                        txTCPChecksums++;
                    }
                    if (txDescCache.extsts & EXTSTS_IPPKT) {
                        ipChecksum(txPacket, true);
                        txIPChecksums++;
                    }
                }

                txPacket->length = txPacketBufPtr - txPacket->data;
                /* this is just because the receive can't handle a packet bigger
                   want to make sure */
                assert(txPacket->length <= 1514);
                txFifo.push_back(txPacket);

                /* this following section is not to spec, but functionally shouldn't
                   be any different.  normally, the chip will wait til the transmit has
                   occurred before writing back the descriptor because it has to wait
                   to see that it was successfully transmitted to decide whether to set
                   CMDSTS_OK or not.  however, in the simulator since it is always
                   successfully transmitted, and writing it exactly to spec would
                   complicate the code, we just do it here
                */

                txDescCache.cmdsts &= ~CMDSTS_OWN;
                txDescCache.cmdsts |= CMDSTS_OK;

                DPRINTF(EthernetDesc,
                        "txDesc writeback:\n\tcmdsts=%08x\n\textsts=%08x\n",
                        txDescCache.cmdsts, txDescCache.extsts);

                txDmaAddr = (regs.txdp + offsetof(ns_desc, cmdsts)) & 0x3fffffff;
                txDmaData = &(txDescCache.cmdsts);
                txDmaLen = sizeof(txDescCache.cmdsts) + sizeof(txDescCache.extsts);
                txDmaFree = dmaDescFree;

                descDmaWrites++;
                descDmaWrBytes += txDmaLen;

                transmit();
                txPacket = 0;

                if (txHalt) {
                    DPRINTF(EthernetSM, "halting TX state machine\n");
                    txState = txIdle;
                    txHalt = false;
                } else
                    txState = txAdvance;

                if (doTxDmaWrite())
                    goto exit;
            }
        } else {
            DPRINTF(EthernetSM, "this descriptor isn't done yet\n");
            txState = txFragRead;

            /* The number of bytes transferred is either whatever is left
               in the descriptor (txDescCnt), or if there is not enough
               room in the fifo, just whatever room is left in the fifo
            */
            txXferLen = min<uint32_t>(txDescCnt, txFifoAvail);

            txDmaAddr = txFragPtr & 0x3fffffff;
            txDmaData = txPacketBufPtr;
            txDmaLen = txXferLen;
            txDmaFree = dmaDataFree;

            if (doTxDmaRead())
                goto exit;
        }
        break;

      case txFragRead:
        if (txDmaState != dmaIdle)
            goto exit;

        txPacketBufPtr += txXferLen;
        txFragPtr += txXferLen;
        txDescCnt -= txXferLen;
        txFifoAvail -= txXferLen;

        txState = txFifoBlock;
        break;

      case txDescWrite:
        if (txDmaState != dmaIdle)
            goto exit;

        if (txDescCache.cmdsts & CMDSTS_INTR) {
            devIntrPost(ISR_TXDESC);
        }

        txState = txAdvance;
        break;

      case txAdvance:
        if (txDescCache.link == 0) {
            txState = txIdle;
        } else {
            txState = txDescRead;
            regs.txdp = txDescCache.link;
            CTDD = false;

            txDmaAddr = txDescCache.link & 0x3fffffff;
            txDmaData = &txDescCache;
            txDmaLen = sizeof(ns_desc);
            txDmaFree = dmaDescFree;

            if (doTxDmaRead())
                goto exit;
        }
        break;

      default:
        panic("invalid state");
    }

    DPRINTF(EthernetSM, "entering next tx state=%s\n",
            NsTxStateStrings[txState]);

    if (txState == txIdle) {
        regs.command &= ~CR_TXE;
        devIntrPost(ISR_TXIDLE);
        return;
    }

    goto next;

  exit:
    /**
     * @todo do we want to schedule a future kick?
     */
    DPRINTF(EthernetSM, "tx state machine exited state=%s\n",
            NsTxStateStrings[txState]);
}

void
NSGigE::transferDone()
{
    if (txFifo.empty())
        return;

    if (txEvent.scheduled())
        txEvent.reschedule(curTick + 1);
    else
        txEvent.schedule(curTick + 1);
}

bool
NSGigE::rxFilter(PacketPtr packet)
{
    bool drop = true;
    string type;

    if (packet->IsUnicast()) {
        type = "unicast";

        // If we're accepting all unicast addresses
        if (acceptUnicast)
            drop = false;

        // If we make a perfect match
        if ((acceptPerfect)
            && (memcmp(rom.perfectMatch, packet->data, sizeof(rom.perfectMatch)) == 0))
            drop = false;

        eth_header *eth = (eth_header *) packet->data;
        if ((acceptArp) && (eth->type == 0x608))
            drop = false;

    } else if (packet->IsBroadcast()) {
        type = "broadcast";

        // if we're accepting broadcasts
        if (acceptBroadcast)
            drop = false;

    } else if (packet->IsMulticast()) {
        type = "multicast";

        // if we're accepting all multicasts
        if (acceptMulticast)
            drop = false;

    } else {
        type = "unknown";

        // oh well, punt on this one
    }

    if (drop) {
        DPRINTF(Ethernet, "rxFilter drop\n");
        DDUMP(EthernetData, packet->data, packet->length);
    }

    return drop;
}

bool
NSGigE::recvPacket(PacketPtr packet)
{
    rxBytes += packet->length;
    rxPackets++;

    DPRINTF(Ethernet, "\n\nReceiving packet from wire, rxFifoAvail = %d\n", MAX_RX_FIFO_SIZE - rxFifoCnt);

    if (rxState == rxIdle) {
        DPRINTF(Ethernet, "receive disabled...packet dropped\n");
        interface->recvDone();
        return true;
    }

    if (rxFilterEnable && rxFilter(packet)) {
        DPRINTF(Ethernet, "packet filtered...dropped\n");
        interface->recvDone();
        return true;
    }

    if ((rxFifoCnt + packet->length) >= MAX_RX_FIFO_SIZE) {
        DPRINTF(Ethernet,
                "packet will not fit in receive buffer...packet dropped\n");
        devIntrPost(ISR_RXORN);
        return false;
    }

    rxFifo.push_back(packet);
    rxFifoCnt += packet->length;
    interface->recvDone();

    rxKick();
    return true;
}

/**
 * does a udp checksum.  if gen is true, then it generates it and puts it in the right place
 * else, it just checks what it calculates against the value in the header in packet
 */
bool
NSGigE::udpChecksum(PacketPtr packet, bool gen)
{
    ip_header *ip = packet->getIpHdr();
    udp_header *hdr = packet->getUdpHdr(ip);

    pseudo_header *pseudo = new pseudo_header;

    pseudo->src_ip_addr = ip->src_ip_addr;
    pseudo->dest_ip_addr = ip->dest_ip_addr;
    pseudo->protocol = ip->protocol;
    pseudo->len = hdr->len;

    uint16_t cksum = checksumCalc((uint16_t *) pseudo, (uint16_t *) hdr,
                                  (uint32_t) hdr->len);

    delete pseudo;
    if (gen)
        hdr->chksum = cksum;
    else
        if (cksum != 0)
            return false;

    return true;
}

bool
NSGigE::tcpChecksum(PacketPtr packet, bool gen)
{
    ip_header *ip = packet->getIpHdr();
    tcp_header *hdr = packet->getTcpHdr(ip);

    uint16_t cksum;
    pseudo_header *pseudo = new pseudo_header;
    if (!gen) {
        pseudo->src_ip_addr = ip->src_ip_addr;
        pseudo->dest_ip_addr = ip->dest_ip_addr;
        pseudo->protocol = reverseEnd16(ip->protocol);
        pseudo->len = reverseEnd16(reverseEnd16(ip->dgram_len) - (ip->vers_len & 0xf)*4);

        cksum = checksumCalc((uint16_t *) pseudo, (uint16_t *) hdr,
                                  (uint32_t) reverseEnd16(pseudo->len));
    } else {
        pseudo->src_ip_addr = 0;
        pseudo->dest_ip_addr = 0;
        pseudo->protocol = hdr->chksum;
        pseudo->len = 0;
        hdr->chksum = 0;
        cksum = checksumCalc((uint16_t *) pseudo, (uint16_t *) hdr,
                             (uint32_t) (reverseEnd16(ip->dgram_len) - (ip->vers_len & 0xf)*4));
    }

    delete pseudo;
    if (gen)
        hdr->chksum = cksum;
    else
        if (cksum != 0)
            return false;

    return true;
}

bool
NSGigE::ipChecksum(PacketPtr packet, bool gen)
{
    ip_header *hdr = packet->getIpHdr();

    uint16_t cksum = checksumCalc(NULL, (uint16_t *) hdr, (hdr->vers_len & 0xf)*4);

    if (gen) {
        DPRINTF(EthernetCksum, "generated checksum: %#x\n", cksum);
        hdr->hdr_chksum = cksum;
    }
    else
        if (cksum != 0)
            return false;

    return true;
}

uint16_t
NSGigE::checksumCalc(uint16_t *pseudo, uint16_t *buf, uint32_t len)
{
    uint32_t sum = 0;

    uint16_t last_pad = 0;
    if (len & 1) {
        last_pad = buf[len/2] & 0xff;
        len--;
        sum += last_pad;
    }

    if (pseudo) {
        sum = pseudo[0] + pseudo[1] + pseudo[2] +
            pseudo[3] + pseudo[4] + pseudo[5];
    }

    for (int i=0; i < (len/2); ++i) {
        sum += buf[i];
    }

    while (sum >> 16)
        sum = (sum >> 16) + (sum & 0xffff);

    return ~sum;
}

//=====================================================================
//
//
void
NSGigE::serialize(ostream &os)
{
    // Serialize the PciDev base class
    PciDev::serialize(os);

    /*
     * Finalize any DMA events now.
     */
    if (rxDmaReadEvent.scheduled())
        rxDmaReadCopy();
    if (rxDmaWriteEvent.scheduled())
        rxDmaWriteCopy();
    if (txDmaReadEvent.scheduled())
        txDmaReadCopy();
    if (txDmaWriteEvent.scheduled())
        txDmaWriteCopy();

    /*
     * Serialize the device registers
     */
    SERIALIZE_SCALAR(regs.command);
    SERIALIZE_SCALAR(regs.config);
    SERIALIZE_SCALAR(regs.mear);
    SERIALIZE_SCALAR(regs.ptscr);
    SERIALIZE_SCALAR(regs.isr);
    SERIALIZE_SCALAR(regs.imr);
    SERIALIZE_SCALAR(regs.ier);
    SERIALIZE_SCALAR(regs.ihr);
    SERIALIZE_SCALAR(regs.txdp);
    SERIALIZE_SCALAR(regs.txdp_hi);
    SERIALIZE_SCALAR(regs.txcfg);
    SERIALIZE_SCALAR(regs.gpior);
    SERIALIZE_SCALAR(regs.rxdp);
    SERIALIZE_SCALAR(regs.rxdp_hi);
    SERIALIZE_SCALAR(regs.rxcfg);
    SERIALIZE_SCALAR(regs.pqcr);
    SERIALIZE_SCALAR(regs.wcsr);
    SERIALIZE_SCALAR(regs.pcr);
    SERIALIZE_SCALAR(regs.rfcr);
    SERIALIZE_SCALAR(regs.rfdr);
    SERIALIZE_SCALAR(regs.srr);
    SERIALIZE_SCALAR(regs.mibc);
    SERIALIZE_SCALAR(regs.vrcr);
    SERIALIZE_SCALAR(regs.vtcr);
    SERIALIZE_SCALAR(regs.vdr);
    SERIALIZE_SCALAR(regs.ccsr);
    SERIALIZE_SCALAR(regs.tbicr);
    SERIALIZE_SCALAR(regs.tbisr);
    SERIALIZE_SCALAR(regs.tanar);
    SERIALIZE_SCALAR(regs.tanlpar);
    SERIALIZE_SCALAR(regs.taner);
    SERIALIZE_SCALAR(regs.tesr);

    SERIALIZE_ARRAY(rom.perfectMatch, EADDR_LEN);

    SERIALIZE_SCALAR(ioEnable);

    /*
     * Serialize the data Fifos
     */
    int txNumPkts = txFifo.size();
    SERIALIZE_SCALAR(txNumPkts);
    int i = 0;
    pktiter_t end = txFifo.end();
    for (pktiter_t p = txFifo.begin(); p != end; ++p) {
        nameOut(os, csprintf("%s.txFifo%d", name(), i++));
        (*p)->serialize(os);
    }

    int rxNumPkts = rxFifo.size();
    SERIALIZE_SCALAR(rxNumPkts);
    i = 0;
    end = rxFifo.end();
    for (pktiter_t p = rxFifo.begin(); p != end; ++p) {
        nameOut(os, csprintf("%s.rxFifo%d", name(), i++));
        (*p)->serialize(os);
    }

    /*
     * Serialize the various helper variables
     */
    bool txPacketExists = txPacket;
    SERIALIZE_SCALAR(txPacketExists);
    if (txPacketExists) {
        nameOut(os, csprintf("%s.txPacket", name()));
        txPacket->serialize(os);
        uint32_t txPktBufPtr = (uint32_t) (txPacketBufPtr - txPacket->data);
        SERIALIZE_SCALAR(txPktBufPtr);
    }

    bool rxPacketExists = rxPacket;
    SERIALIZE_SCALAR(rxPacketExists);
    if (rxPacketExists) {
        nameOut(os, csprintf("%s.rxPacket", name()));
        rxPacket->serialize(os);
        uint32_t rxPktBufPtr = (uint32_t) (rxPacketBufPtr - rxPacket->data);
        SERIALIZE_SCALAR(rxPktBufPtr);
    }

    SERIALIZE_SCALAR(txXferLen);
    SERIALIZE_SCALAR(rxXferLen);

    /*
     * Serialize DescCaches
     */
    SERIALIZE_SCALAR(txDescCache.link);
    SERIALIZE_SCALAR(txDescCache.bufptr);
    SERIALIZE_SCALAR(txDescCache.cmdsts);
    SERIALIZE_SCALAR(txDescCache.extsts);
    SERIALIZE_SCALAR(rxDescCache.link);
    SERIALIZE_SCALAR(rxDescCache.bufptr);
    SERIALIZE_SCALAR(rxDescCache.cmdsts);
    SERIALIZE_SCALAR(rxDescCache.extsts);

    /*
     * Serialize tx state machine
     */
    int txState = this->txState;
    SERIALIZE_SCALAR(txState);
    SERIALIZE_SCALAR(CTDD);
    SERIALIZE_SCALAR(txFifoAvail);
    SERIALIZE_SCALAR(txHalt);
    SERIALIZE_SCALAR(txFragPtr);
    SERIALIZE_SCALAR(txDescCnt);
    int txDmaState = this->txDmaState;
    SERIALIZE_SCALAR(txDmaState);

    /*
     * Serialize rx state machine
     */
    int rxState = this->rxState;
    SERIALIZE_SCALAR(rxState);
    SERIALIZE_SCALAR(CRDD);
    SERIALIZE_SCALAR(rxPktBytes);
    SERIALIZE_SCALAR(rxFifoCnt);
    SERIALIZE_SCALAR(rxHalt);
    SERIALIZE_SCALAR(rxDescCnt);
    int rxDmaState = this->rxDmaState;
    SERIALIZE_SCALAR(rxDmaState);

    SERIALIZE_SCALAR(extstsEnable);

    /*
     * If there's a pending transmit, store the time so we can
     * reschedule it later
     */
    Tick transmitTick = txEvent.scheduled() ? txEvent.when() - curTick : 0;
    SERIALIZE_SCALAR(transmitTick);

    /*
     * receive address filter settings
     */
    SERIALIZE_SCALAR(rxFilterEnable);
    SERIALIZE_SCALAR(acceptBroadcast);
    SERIALIZE_SCALAR(acceptMulticast);
    SERIALIZE_SCALAR(acceptUnicast);
    SERIALIZE_SCALAR(acceptPerfect);
    SERIALIZE_SCALAR(acceptArp);

    /*
     * Keep track of pending interrupt status.
     */
    SERIALIZE_SCALAR(intrTick);
    SERIALIZE_SCALAR(cpuPendingIntr);
    Tick intrEventTick = 0;
    if (intrEvent)
        intrEventTick = intrEvent->when();
    SERIALIZE_SCALAR(intrEventTick);

}

void
NSGigE::unserialize(Checkpoint *cp, const std::string &section)
{
    // Unserialize the PciDev base class
    PciDev::unserialize(cp, section);

    UNSERIALIZE_SCALAR(regs.command);
    UNSERIALIZE_SCALAR(regs.config);
    UNSERIALIZE_SCALAR(regs.mear);
    UNSERIALIZE_SCALAR(regs.ptscr);
    UNSERIALIZE_SCALAR(regs.isr);
    UNSERIALIZE_SCALAR(regs.imr);
    UNSERIALIZE_SCALAR(regs.ier);
    UNSERIALIZE_SCALAR(regs.ihr);
    UNSERIALIZE_SCALAR(regs.txdp);
    UNSERIALIZE_SCALAR(regs.txdp_hi);
    UNSERIALIZE_SCALAR(regs.txcfg);
    UNSERIALIZE_SCALAR(regs.gpior);
    UNSERIALIZE_SCALAR(regs.rxdp);
    UNSERIALIZE_SCALAR(regs.rxdp_hi);
    UNSERIALIZE_SCALAR(regs.rxcfg);
    UNSERIALIZE_SCALAR(regs.pqcr);
    UNSERIALIZE_SCALAR(regs.wcsr);
    UNSERIALIZE_SCALAR(regs.pcr);
    UNSERIALIZE_SCALAR(regs.rfcr);
    UNSERIALIZE_SCALAR(regs.rfdr);
    UNSERIALIZE_SCALAR(regs.srr);
    UNSERIALIZE_SCALAR(regs.mibc);
    UNSERIALIZE_SCALAR(regs.vrcr);
    UNSERIALIZE_SCALAR(regs.vtcr);
    UNSERIALIZE_SCALAR(regs.vdr);
    UNSERIALIZE_SCALAR(regs.ccsr);
    UNSERIALIZE_SCALAR(regs.tbicr);
    UNSERIALIZE_SCALAR(regs.tbisr);
    UNSERIALIZE_SCALAR(regs.tanar);
    UNSERIALIZE_SCALAR(regs.tanlpar);
    UNSERIALIZE_SCALAR(regs.taner);
    UNSERIALIZE_SCALAR(regs.tesr);

    UNSERIALIZE_ARRAY(rom.perfectMatch, EADDR_LEN);

    UNSERIALIZE_SCALAR(ioEnable);

    /*
     * unserialize the data fifos
     */
    int txNumPkts;
    UNSERIALIZE_SCALAR(txNumPkts);
    int i;
    for (i = 0; i < txNumPkts; ++i) {
        PacketPtr p = new EtherPacket;
        p->unserialize(cp, csprintf("%s.rxFifo%d", section, i));
        txFifo.push_back(p);
    }

    int rxNumPkts;
    UNSERIALIZE_SCALAR(rxNumPkts);
    for (i = 0; i < rxNumPkts; ++i) {
        PacketPtr p = new EtherPacket;
        p->unserialize(cp, csprintf("%s.rxFifo%d", section, i));
        rxFifo.push_back(p);
    }

    /*
     * unserialize the various helper variables
     */
    bool txPacketExists;
    UNSERIALIZE_SCALAR(txPacketExists);
    if (txPacketExists) {
        txPacket = new EtherPacket;
        txPacket->unserialize(cp, csprintf("%s.txPacket", section));
        uint32_t txPktBufPtr;
        UNSERIALIZE_SCALAR(txPktBufPtr);
        txPacketBufPtr = (uint8_t *) txPacket->data + txPktBufPtr;
    } else
        txPacket = 0;

    bool rxPacketExists;
    UNSERIALIZE_SCALAR(rxPacketExists);
    rxPacket = 0;
    if (rxPacketExists) {
        rxPacket = new EtherPacket;
        rxPacket->unserialize(cp, csprintf("%s.rxPacket", section));
        uint32_t rxPktBufPtr;
        UNSERIALIZE_SCALAR(rxPktBufPtr);
        rxPacketBufPtr = (uint8_t *) rxPacket->data + rxPktBufPtr;
    } else
        rxPacket = 0;

    UNSERIALIZE_SCALAR(txXferLen);
    UNSERIALIZE_SCALAR(rxXferLen);

    /*
     * Unserialize DescCaches
     */
    UNSERIALIZE_SCALAR(txDescCache.link);
    UNSERIALIZE_SCALAR(txDescCache.bufptr);
    UNSERIALIZE_SCALAR(txDescCache.cmdsts);
    UNSERIALIZE_SCALAR(txDescCache.extsts);
    UNSERIALIZE_SCALAR(rxDescCache.link);
    UNSERIALIZE_SCALAR(rxDescCache.bufptr);
    UNSERIALIZE_SCALAR(rxDescCache.cmdsts);
    UNSERIALIZE_SCALAR(rxDescCache.extsts);

    /*
     * unserialize tx state machine
     */
    int txState;
    UNSERIALIZE_SCALAR(txState);
    this->txState = (TxState) txState;
    UNSERIALIZE_SCALAR(CTDD);
    UNSERIALIZE_SCALAR(txFifoAvail);
    UNSERIALIZE_SCALAR(txHalt);
    UNSERIALIZE_SCALAR(txFragPtr);
    UNSERIALIZE_SCALAR(txDescCnt);
    int txDmaState;
    UNSERIALIZE_SCALAR(txDmaState);
    this->txDmaState = (DmaState) txDmaState;

    /*
     * unserialize rx state machine
     */
    int rxState;
    UNSERIALIZE_SCALAR(rxState);
    this->rxState = (RxState) rxState;
    UNSERIALIZE_SCALAR(CRDD);
    UNSERIALIZE_SCALAR(rxPktBytes);
    UNSERIALIZE_SCALAR(rxFifoCnt);
    UNSERIALIZE_SCALAR(rxHalt);
    UNSERIALIZE_SCALAR(rxDescCnt);
    int rxDmaState;
    UNSERIALIZE_SCALAR(rxDmaState);
    this->rxDmaState = (DmaState) rxDmaState;

    UNSERIALIZE_SCALAR(extstsEnable);

     /*
     * If there's a pending transmit, reschedule it now
     */
    Tick transmitTick;
    UNSERIALIZE_SCALAR(transmitTick);
    if (transmitTick)
        txEvent.schedule(curTick + transmitTick);

    /*
     * unserialize receive address filter settings
     */
    UNSERIALIZE_SCALAR(rxFilterEnable);
    UNSERIALIZE_SCALAR(acceptBroadcast);
    UNSERIALIZE_SCALAR(acceptMulticast);
    UNSERIALIZE_SCALAR(acceptUnicast);
    UNSERIALIZE_SCALAR(acceptPerfect);
    UNSERIALIZE_SCALAR(acceptArp);

    /*
     * Keep track of pending interrupt status.
     */
    UNSERIALIZE_SCALAR(intrTick);
    UNSERIALIZE_SCALAR(cpuPendingIntr);
    Tick intrEventTick;
    UNSERIALIZE_SCALAR(intrEventTick);
    if (intrEventTick) {
        intrEvent = new IntrEvent(this, true);
        intrEvent->schedule(intrEventTick);
    }

    /*
     * re-add addrRanges to bus bridges
     */
    if (pioInterface) {
        pioInterface->addAddrRange(BARAddrs[0], BARAddrs[0] + BARSize[0] - 1);
        pioInterface->addAddrRange(BARAddrs[1], BARAddrs[1] + BARSize[1] - 1);
    }
}

Tick
NSGigE::cacheAccess(MemReqPtr &req)
{
    DPRINTF(EthernetPIO, "timing access to paddr=%#x (daddr=%#x)\n",
            req->paddr, req->paddr - addr);
    return curTick + pioLatency;
}
//=====================================================================


//********** helper functions******************************************

uint16_t reverseEnd16(uint16_t num)
{
    uint16_t reverse = (num & 0xff)<<8;
    reverse += ((num & 0xff00) >> 8);
    return reverse;
}

uint32_t reverseEnd32(uint32_t num)
{
    uint32_t reverse = (reverseEnd16(num & 0xffff)) << 16;
    reverse += reverseEnd16((uint16_t) ((num & 0xffff0000) >> 8));
    return reverse;
}



//=====================================================================

BEGIN_DECLARE_SIM_OBJECT_PARAMS(NSGigEInt)

    SimObjectParam<EtherInt *> peer;
    SimObjectParam<NSGigE *> device;

END_DECLARE_SIM_OBJECT_PARAMS(NSGigEInt)

BEGIN_INIT_SIM_OBJECT_PARAMS(NSGigEInt)

    INIT_PARAM_DFLT(peer, "peer interface", NULL),
    INIT_PARAM(device, "Ethernet device of this interface")

END_INIT_SIM_OBJECT_PARAMS(NSGigEInt)

CREATE_SIM_OBJECT(NSGigEInt)
{
    NSGigEInt *dev_int = new NSGigEInt(getInstanceName(), device);

    EtherInt *p = (EtherInt *)peer;
    if (p) {
        dev_int->setPeer(p);
        p->setPeer(dev_int);
    }

    return dev_int;
}

REGISTER_SIM_OBJECT("NSGigEInt", NSGigEInt)


BEGIN_DECLARE_SIM_OBJECT_PARAMS(NSGigE)

    Param<Tick> tx_delay;
    Param<Tick> rx_delay;
    SimObjectParam<IntrControl *> intr_ctrl;
    Param<Tick> intr_delay;
    SimObjectParam<MemoryController *> mmu;
    SimObjectParam<PhysicalMemory *> physmem;
    Param<bool> rx_filter;
    Param<string> hardware_address;
    SimObjectParam<Bus*> header_bus;
    SimObjectParam<Bus*> payload_bus;
    SimObjectParam<HierParams *> hier;
    Param<Tick> pio_latency;
    Param<bool> dma_desc_free;
    Param<bool> dma_data_free;
    Param<Tick> dma_read_delay;
    Param<Tick> dma_write_delay;
    Param<Tick> dma_read_factor;
    Param<Tick> dma_write_factor;
    SimObjectParam<PciConfigAll *> configspace;
    SimObjectParam<PciConfigData *> configdata;
    SimObjectParam<Tsunami *> tsunami;
    Param<uint32_t> pci_bus;
    Param<uint32_t> pci_dev;
    Param<uint32_t> pci_func;

END_DECLARE_SIM_OBJECT_PARAMS(NSGigE)

BEGIN_INIT_SIM_OBJECT_PARAMS(NSGigE)

    INIT_PARAM_DFLT(tx_delay, "Transmit Delay", 1000),
    INIT_PARAM_DFLT(rx_delay, "Receive Delay", 1000),
    INIT_PARAM(intr_ctrl, "Interrupt Controller"),
    INIT_PARAM_DFLT(intr_delay, "Interrupt Delay in microseconds", 0),
    INIT_PARAM(mmu, "Memory Controller"),
    INIT_PARAM(physmem, "Physical Memory"),
    INIT_PARAM_DFLT(rx_filter, "Enable Receive Filter", true),
    INIT_PARAM_DFLT(hardware_address, "Ethernet Hardware Address",
                    "00:99:00:00:00:01"),
    INIT_PARAM_DFLT(header_bus, "The IO Bus to attach to for headers", NULL),
    INIT_PARAM_DFLT(payload_bus, "The IO Bus to attach to for payload", NULL),
    INIT_PARAM_DFLT(hier, "Hierarchy global variables", &defaultHierParams),
    INIT_PARAM_DFLT(pio_latency, "Programmed IO latency", 1000),
    INIT_PARAM_DFLT(dma_desc_free, "DMA of Descriptors is free", false),
    INIT_PARAM_DFLT(dma_data_free, "DMA of Data is free", false),
    INIT_PARAM_DFLT(dma_read_delay, "fixed delay for dma reads", 0),
    INIT_PARAM_DFLT(dma_write_delay, "fixed delay for dma writes", 0),
    INIT_PARAM_DFLT(dma_read_factor, "multiplier for dma reads", 0),
    INIT_PARAM_DFLT(dma_write_factor, "multiplier for dma writes", 0),
    INIT_PARAM(configspace, "PCI Configspace"),
    INIT_PARAM(configdata, "PCI Config data"),
    INIT_PARAM(tsunami, "Tsunami"),
    INIT_PARAM(pci_bus, "PCI bus"),
    INIT_PARAM(pci_dev, "PCI device number"),
    INIT_PARAM(pci_func, "PCI function code")

END_INIT_SIM_OBJECT_PARAMS(NSGigE)


CREATE_SIM_OBJECT(NSGigE)
{
    int eaddr[6];
    sscanf(((string)hardware_address).c_str(), "%x:%x:%x:%x:%x:%x",
           &eaddr[0], &eaddr[1], &eaddr[2], &eaddr[3], &eaddr[4], &eaddr[5]);

    return new NSGigE(getInstanceName(), intr_ctrl, intr_delay,
                      physmem, tx_delay, rx_delay, mmu, hier, header_bus,
                      payload_bus, pio_latency, dma_desc_free, dma_data_free,
                      dma_read_delay, dma_write_delay, dma_read_factor,
                      dma_write_factor, configspace, configdata,
                      tsunami, pci_bus, pci_dev, pci_func, rx_filter, eaddr);
}

REGISTER_SIM_OBJECT("NSGigE", NSGigE)