/////////////////////////////////////////////////////////////////////////
// $Id: ne2k.cc,v 1.56.2.1 2004/02/02 22:37:22 cbothamy Exp $
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2002  MandrakeSoft S.A.
//
//    MandrakeSoft S.A.
//    43, rue d'Aboukir
//    75002 Paris - France
//    http://www.linux-mandrake.com/
//    http://www.mandrakesoft.com/
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

// Peter Grehan (grehan@iprg.nokia.com) coded all of this
// NE2000/ether stuff.
//#include "vl.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "slirp/slirp.h"
#include "slirp/queue.h"
#ifdef USE_PCAP_NETWORKING
#include <pcap.h>
#endif

#include "ibm.h"
#include "device.h"

#include "nethandler.h"

#include "config.h"
#include "io.h"
#include "ne2000.h"
#include "pic.h"
#include "pci.h"
#include "timer.h"

/*MAC address*/
uint8_t maclocal[6];

typedef enum { NE2000_NE2000, NE2000_RTL8029AS } ne2000_type;

#define NE2000_PCI_IRQ -1

#define NETBLOCKING 0 // we won't block our pcap

//#define NE2000_DEBUG

#ifdef USE_PCAP_NETWORKING

pcap_t *net_pcap;
#endif

queueADT slirpq;
int net_slirp_inited = 0;
int net_is_slirp = 1; // by default we go with slirp
int net_is_pcap = 0;  // and pretend pcap is dead.
int fizz = 0;
void slirp_tic();

#define BX_RESET_HARDWARE 0
#define BX_RESET_SOFTWARE 1

// Never completely fill the ne2k ring so that we never
// hit the unclear completely full buffer condition.
#define BX_NE2K_NEVER_FULL_RING (1)

#define BX_NE2K_MEMSIZ (32 * 1024)
#define BX_NE2K_MEMSTART (16 * 1024)
#define BX_NE2K_MEMEND (BX_NE2K_MEMSTART + BX_NE2K_MEMSIZ)

typedef struct ne2000_t {
        //
        // ne2k register state

        //
        // Page 0
        //
        //  Command Register - 00h read/write
        struct CR_t {
                int stop;         // STP - Software Reset command
                int start;        // START - start the NIC
                int tx_packet;    // TXP - initiate packet transmission
                uint8_t rdma_cmd; // RD0,RD1,RD2 - Remote DMA command
                uint8_t pgsel;    // PS0,PS1 - Page select
        } CR;
        // Interrupt Status Register - 07h read/write
        struct ISR_t {
                int pkt_rx;    // PRX - packet received with no errors
                int pkt_tx;    // PTX - packet transmitted with no errors
                int rx_err;    // RXE - packet received with 1 or more errors
                int tx_err;    // TXE - packet tx'd       "  " "    "    "
                int overwrite; // OVW - rx buffer resources exhausted
                int cnt_oflow; // CNT - network tally counter MSB's set
                int rdma_done; // RDC - remote DMA complete
                int reset;     // RST - reset status
        } ISR;
        // Interrupt Mask Register - 0fh write
        struct IMR_t {
                int rx_inte;    // PRXE - packet rx interrupt enable
                int tx_inte;    // PTXE - packet tx interrput enable
                int rxerr_inte; // RXEE - rx error interrupt enable
                int txerr_inte; // TXEE - tx error interrupt enable
                int overw_inte; // OVWE - overwrite warn int enable
                int cofl_inte;  // CNTE - counter o'flow int enable
                int rdma_inte;  // RDCE - remote DMA complete int enable
                int reserved;   //  D7 - reserved
        } IMR;
        // Data Configuration Register - 0eh write
        struct DCR_t {
                int wdsize;        // WTS - 8/16-bit select
                int endian;        // BOS - byte-order select
                int longaddr;      // LAS - long-address select
                int loop;          // LS  - loopback select
                int auto_rx;       // AR  - auto-remove rx packets with remote DMA
                uint8_t fifo_size; // FT0,FT1 - fifo threshold
        } DCR;
        // Transmit Configuration Register - 0dh write
        struct TCR_t {
                int crc_disable;   // CRC - inhibit tx CRC
                uint8_t loop_cntl; // LB0,LB1 - loopback control
                int ext_stoptx;    // ATD - allow tx disable by external mcast
                int coll_prio;     // OFST - backoff algorithm select
                uint8_t reserved;  //  D5,D6,D7 - reserved
        } TCR;
        // Transmit Status Register - 04h read
        struct TSR_t {
                int tx_ok;      // PTX - tx complete without error
                int reserved;   //  D1 - reserved
                int collided;   // COL - tx collided >= 1 times
                int aborted;    // ABT - aborted due to excessive collisions
                int no_carrier; // CRS - carrier-sense lost
                int fifo_ur;    // FU  - FIFO underrun
                int cd_hbeat;   // CDH - no tx cd-heartbeat from transceiver
                int ow_coll;    // OWC - out-of-window collision
        } TSR;
        // Receive Configuration Register - 0ch write
        struct RCR_t {
                int errors_ok;    // SEP - accept pkts with rx errors
                int runts_ok;     // AR  - accept < 64-byte runts
                int broadcast;    // AB  - accept eth broadcast address
                int multicast;    // AM  - check mcast hash array
                int promisc;      // PRO - accept all packets
                int monitor;      // MON - check pkts, but don't rx
                uint8_t reserved; //  D6,D7 - reserved
        } RCR;
        // Receive Status Register - 0ch read
        struct RSR_t {
                int rx_ok;       // PRX - rx complete without error
                int bad_crc;     // CRC - Bad CRC detected
                int bad_falign;  // FAE - frame alignment error
                int fifo_or;     // FO  - FIFO overrun
                int rx_missed;   // MPA - missed packet error
                int rx_mbit;     // PHY - unicast or mcast/bcast address match
                int rx_disabled; // DIS - set when in monitor mode
                int deferred;    // DFR - collision active
        } RSR;

        uint16_t local_dma;    // 01,02h read ; current local DMA addr
        uint8_t page_start;    // 01h write ; page start register
        uint8_t page_stop;     // 02h write ; page stop register
        uint8_t bound_ptr;     // 03h read/write ; boundary pointer
        uint8_t tx_page_start; // 04h write ; transmit page start register
        uint8_t num_coll;      // 05h read  ; number-of-collisions register
        uint16_t tx_bytes;     // 05,06h write ; transmit byte-count register
        uint8_t fifo;          // 06h read  ; FIFO
        uint16_t remote_dma;   // 08,09h read ; current remote DMA addr
        uint16_t remote_start; // 08,09h write ; remote start address register
        uint16_t remote_bytes; // 0a,0bh write ; remote byte-count register
        uint8_t tallycnt_0;    // 0dh read  ; tally counter 0 (frame align errors)
        uint8_t tallycnt_1;    // 0eh read  ; tally counter 1 (CRC errors)
        uint8_t tallycnt_2;    // 0fh read  ; tally counter 2 (missed pkt errors)

        //
        // Page 1
        //
        //   Command Register 00h (repeated)
        //
        uint8_t physaddr[6]; // 01-06h read/write ; MAC address
        uint8_t curr_page;   // 07h read/write ; current page register
        uint8_t mchash[8];   // 08-0fh read/write ; multicast hash array

        //
        // Page 2  - diagnostic use only
        //
        //   Command Register 00h (repeated)
        //
        //   Page Start Register 01h read  (repeated)
        //   Page Stop Register  02h read  (repeated)
        //   Current Local DMA Address 01,02h write (repeated)
        //   Transmit Page start address 04h read (repeated)
        //   Receive Configuration Register 0ch read (repeated)
        //   Transmit Configuration Register 0dh read (repeated)
        //   Data Configuration Register 0eh read (repeated)
        //   Interrupt Mask Register 0fh read (repeated)
        //
        uint8_t rempkt_ptr;   // 03h read/write ; remote next-packet pointer
        uint8_t localpkt_ptr; // 05h read/write ; local next-packet pointer
        uint16_t address_cnt; // 06,07h read/write ; address counter

        //
        // Page 3  - should never be modified.
        //

        // Novell ASIC state
        uint8_t macaddr[32];         // ASIC ROM'd MAC address, even bytes
        uint8_t mem[BX_NE2K_MEMSIZ]; // on-chip packet memory

        // ne2k internal state
        uint32_t base_address;
        int base_irq;
        int tx_timer_index;
        int tx_timer_active;

        ne2000_type type;

        /*PCI stuff*/
        int is_pci;
        int card;
        uint32_t base_addr;
        uint8_t pci_command;
        uint8_t int_line;

        /*RTL8029AS registers*/
        uint8_t config0, config2, config3;
        uint8_t _9346cr;
} ne2000_t;

static void ne2000_tx_event(int val, void *p);

void ne2000_rx_frame(void *p, const void *buf, int io_len);

static void ne2000_setirq(ne2000_t *ne2000, int irq) { ne2000->base_irq = irq; }

static void ne2000_raise_irq(ne2000_t *ne2000) {
        if (ne2000->is_pci)
                pci_set_irq(ne2000->card, PCI_INTA);
        else
                picint(1 << ne2000->base_irq);
}

static void ne2000_lower_irq(ne2000_t *ne2000) {
        if (ne2000->is_pci)
                pci_clear_irq(ne2000->card, PCI_INTA);
        else
                picintc(1 << ne2000->base_irq);
}

//
// reset - restore state to power-up, cancelling all i/o
//
static void ne2000_reset(int type, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
        int i;

        pclog("ne2000 reset\n");

        // Initialise the mac address area by doubling the physical address
        ne2000->macaddr[0] = ne2000->physaddr[0];
        ne2000->macaddr[1] = ne2000->physaddr[0];
        ne2000->macaddr[2] = ne2000->physaddr[1];
        ne2000->macaddr[3] = ne2000->physaddr[1];
        ne2000->macaddr[4] = ne2000->physaddr[2];
        ne2000->macaddr[5] = ne2000->physaddr[2];
        ne2000->macaddr[6] = ne2000->physaddr[3];
        ne2000->macaddr[7] = ne2000->physaddr[3];
        ne2000->macaddr[8] = ne2000->physaddr[4];
        ne2000->macaddr[9] = ne2000->physaddr[4];
        ne2000->macaddr[10] = ne2000->physaddr[5];
        ne2000->macaddr[11] = ne2000->physaddr[5];

        // ne2k signature
        for (i = 12; i < 32; i++)
                ne2000->macaddr[i] = 0x57;

        // Zero out registers and memory
        memset(&ne2000->CR, 0, sizeof(ne2000->CR));
        memset(&ne2000->ISR, 0, sizeof(ne2000->ISR));
        memset(&ne2000->IMR, 0, sizeof(ne2000->IMR));
        memset(&ne2000->DCR, 0, sizeof(ne2000->DCR));
        memset(&ne2000->TCR, 0, sizeof(ne2000->TCR));
        memset(&ne2000->TSR, 0, sizeof(ne2000->TSR));
        // memset( & ne2000->RCR, 0, sizeof(ne2000->RCR));
        memset(&ne2000->RSR, 0, sizeof(ne2000->RSR));
        ne2000->tx_timer_active = 0;
        ne2000->local_dma = 0;
        ne2000->page_start = 0;
        ne2000->page_stop = 0;
        ne2000->bound_ptr = 0;
        ne2000->tx_page_start = 0;
        ne2000->num_coll = 0;
        ne2000->tx_bytes = 0;
        ne2000->fifo = 0;
        ne2000->remote_dma = 0;
        ne2000->remote_start = 0;
        ne2000->remote_bytes = 0;
        ne2000->tallycnt_0 = 0;
        ne2000->tallycnt_1 = 0;
        ne2000->tallycnt_2 = 0;

        // memset( & ne2000->physaddr, 0, sizeof(ne2000->physaddr));
        // memset( & ne2000->mchash, 0, sizeof(ne2000->mchash));
        ne2000->curr_page = 0;

        ne2000->rempkt_ptr = 0;
        ne2000->localpkt_ptr = 0;
        ne2000->address_cnt = 0;

        memset(&ne2000->mem, 0, sizeof(ne2000->mem));

        // Set power-up conditions
        ne2000->CR.stop = 1;
        ne2000->CR.rdma_cmd = 4;
        ne2000->ISR.reset = 1;
        ne2000->DCR.longaddr = 1;
        ne2000_raise_irq(ne2000);
        ne2000_lower_irq(ne2000);

        // DEV_pic_lower_irq(ne2000->base_irq);
}

#include "bswap.h"

//
// chipmem_read/chipmem_write - access the 64K private RAM.
// The ne2000 memory is accessed through the data port of
// the asic (offset 0) after setting up a remote-DMA transfer.
// Both byte and word accesses are allowed.
// The first 16 bytes contains the MAC address at even locations,
// and there is 16K of buffer memory starting at 16K
//
static inline uint8_t ne2000_chipmem_read_b(uint32_t address, ne2000_t *ne2000) {
        // ROM'd MAC address
        if ((address >= 0) && (address <= 31))
                return ne2000->macaddr[address];

        if ((address >= BX_NE2K_MEMSTART) && (address < BX_NE2K_MEMEND))
                return ne2000->mem[address - BX_NE2K_MEMSTART];
        else
                return 0xff;
}

static inline uint16_t ne2000_chipmem_read_w(uint32_t address, ne2000_t *ne2000) {
        // ROM'd MAC address
        if ((address >= 0) && (address <= 31))
                return le16_to_cpu(*(uint16_t *)(ne2000->macaddr + address));

        if ((address >= BX_NE2K_MEMSTART) && (address < BX_NE2K_MEMEND))
                return le16_to_cpu(*(uint16_t *)(ne2000->mem + (address - BX_NE2K_MEMSTART)));
        else
                return 0xffff;
}

static inline void ne2000_chipmem_write_b(uint32_t address, uint8_t value, ne2000_t *ne2000) {
        if ((address >= BX_NE2K_MEMSTART) && (address < BX_NE2K_MEMEND))
                ne2000->mem[address - BX_NE2K_MEMSTART] = value & 0xff;
}

static inline void ne2000_chipmem_write_w(uint32_t address, uint16_t value, ne2000_t *ne2000) {
        if ((address >= BX_NE2K_MEMSTART) && (address < BX_NE2K_MEMEND))
                *(uint16_t *)(ne2000->mem + (address - BX_NE2K_MEMSTART)) = cpu_to_le16(value);
}

//
// asic_read/asic_write - This is the high 16 bytes of i/o space
// (the lower 16 bytes is for the DS8390). Only two locations
// are used: offset 0, which is used for data transfer, and
// offset 0xf, which is used to reset the device.
// The data transfer port is used to as 'external' DMA to the
// DS8390. The chip has to have the DMA registers set up, and
// after that, insw/outsw instructions can be used to move
// the appropriate number of bytes to/from the device.
//
uint16_t ne2000_dma_read(int io_len, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;

        //
        // The 8390 bumps the address and decreases the byte count
        // by the selected word size after every access, not by
        // the amount of data requested by the host (io_len).
        //
        ne2000->remote_dma += io_len;
        if (ne2000->remote_dma == ne2000->page_stop << 8)
                ne2000->remote_dma = ne2000->page_start << 8;

        // keep s.remote_bytes from underflowing
        if (ne2000->remote_bytes > 1)
                ne2000->remote_bytes -= io_len;
        else
                ne2000->remote_bytes = 0;

        // If all bytes have been written, signal remote-DMA complete
        if (ne2000->remote_bytes == 0) {
                ne2000->ISR.rdma_done = 1;
                if (ne2000->IMR.rdma_inte) {
                        ne2000_raise_irq(ne2000);
                }
        }

        return 0;
}

uint16_t ne2000_asic_read_w(uint16_t offset, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
        int retval;

        if (ne2000->DCR.wdsize & 0x01) {
                /* 16 bit access */
                retval = ne2000_chipmem_read_w(ne2000->remote_dma, ne2000);
                ne2000_dma_read(2, ne2000);
        } else {
                /* 8 bit access */
                retval = ne2000_chipmem_read_b(ne2000->remote_dma, ne2000);
                ne2000_dma_read(1, ne2000);
        }
#ifdef NE2000_DEBUG
        pclog("asic read val=0x%04x\n", retval);
#endif
        return retval;
}

void ne2000_dma_write(int io_len, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;

        // is this right ??? asic_read uses DCR.wordsize
        ne2000->remote_dma += io_len;
        if (ne2000->remote_dma == ne2000->page_stop << 8)
                ne2000->remote_dma = ne2000->page_start << 8;

        ne2000->remote_bytes -= io_len;
        if (ne2000->remote_bytes > BX_NE2K_MEMSIZ)
                ne2000->remote_bytes = 0;

        // If all bytes have been written, signal remote-DMA complete
        if (ne2000->remote_bytes == 0) {
                ne2000->ISR.rdma_done = 1;
                if (ne2000->IMR.rdma_inte) {
                        ne2000_raise_irq(ne2000);
                }
        }
}

void ne2000_asic_write_w(uint16_t offset, uint16_t value, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
#ifdef NE2000_DEBUG
        pclog("asic write val=0x%04x\n", value);
#endif
        if (ne2000->remote_bytes == 0)
                return;
        if (ne2000->DCR.wdsize & 0x01) {
                /* 16 bit access */
                ne2000_chipmem_write_w(ne2000->remote_dma, value, ne2000);
                ne2000_dma_write(2, ne2000);
        } else {
                /* 8 bit access */
                ne2000_chipmem_write_b(ne2000->remote_dma, value, ne2000);
                ne2000_dma_write(1, ne2000);
        }
}

uint8_t ne2000_asic_read_b(uint16_t offset, void *p) {
        if (offset & 1)
                return ne2000_asic_read_w(offset & ~1, p) >> 1;
        return ne2000_asic_read_w(offset, p) & 0xff;
}

void ne2000_asic_write_b(uint16_t offset, uint8_t value, void *p) {
        if (offset & 1)
                ne2000_asic_write_w(offset & ~1, value << 8, p);
        else
                ne2000_asic_write_w(offset, value, p);
}

uint8_t ne2000_reset_read(uint16_t offset, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
        ne2000_reset(BX_RESET_SOFTWARE, ne2000);
        return 0;
}

void ne2000_reset_write(uint16_t offset, uint8_t value, void *p) {}

//
// read_handler/read - i/o 'catcher' function called from BOCHS
// mainline when the CPU attempts a read in the i/o space registered
// by this ne2000 instance
//
uint8_t ne2000_read(uint16_t address, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
        int ret = 0;

#ifdef NE2000_DEBUG
        pclog("read addr %x\n", address);
#endif
        address &= 0xf;

        if (address == 0x00) {
                ret = (((ne2000->CR.pgsel & 0x03) << 6) | ((ne2000->CR.rdma_cmd & 0x07) << 3) | (ne2000->CR.tx_packet << 2) |
                       (ne2000->CR.start << 1) | (ne2000->CR.stop));
#ifdef NE2000_DEBUG
                pclog("read CR returns 0x%08x\n", ret);
#endif
        } else {
                switch (ne2000->CR.pgsel) {
                case 0x00:
#ifdef NE2000_DEBUG
                        pclog("page 0 read from port %04x\n", address);
#endif
                        switch (address) {
                        case 0x1: // CLDA0
                                return ne2000->local_dma & 0xff;

                        case 0x2: // CLDA1
                                return ne2000->local_dma >> 8;

                        case 0x3: // BNRY
                                return ne2000->bound_ptr;

                        case 0x4: // TSR
                                return ((ne2000->TSR.ow_coll << 7) | (ne2000->TSR.cd_hbeat << 6) | (ne2000->TSR.fifo_ur << 5) |
                                        (ne2000->TSR.no_carrier << 4) | (ne2000->TSR.aborted << 3) | (ne2000->TSR.collided << 2) |
                                        (ne2000->TSR.tx_ok));

                        case 0x5: // NCR
                                return ne2000->num_coll;

                        case 0x6: // FIFO
                                  // reading FIFO is only valid in loopback mode
#ifdef NE2000_DEBUG
                                pclog("reading FIFO not supported yet\n");
#endif
                                return ne2000->fifo;

                        case 0x7: // ISR
                                return ((ne2000->ISR.reset << 7) | (ne2000->ISR.rdma_done << 6) | (ne2000->ISR.cnt_oflow << 5) |
                                        (ne2000->ISR.overwrite << 4) | (ne2000->ISR.tx_err << 3) | (ne2000->ISR.rx_err << 2) |
                                        (ne2000->ISR.pkt_tx << 1) | (ne2000->ISR.pkt_rx));

                        case 0x8: // CRDA0
                                return ne2000->remote_dma & 0xff;

                        case 0x9: // CRDA1
                                return ne2000->remote_dma >> 8;

                        case 0xa: // reserved
#ifdef NE2000_DEBUG
                                pclog("reserved read - page 0, 0xa\n");
#endif
                                return 0xff;

                        case 0xb: // reserved
#ifdef NE2000_DEBUG
                                pclog("reserved read - page 0, 0xb\n");
#endif
                                return 0xff;

                        case 0xc: // RSR
                                return ((ne2000->RSR.deferred << 7) | (ne2000->RSR.rx_disabled << 6) |
                                        (ne2000->RSR.rx_mbit << 5) | (ne2000->RSR.rx_missed << 4) | (ne2000->RSR.fifo_or << 3) |
                                        (ne2000->RSR.bad_falign << 2) | (ne2000->RSR.bad_crc << 1) | (ne2000->RSR.rx_ok));

                        case 0xd: // CNTR0
                                return ne2000->tallycnt_0;

                        case 0xe: // CNTR1
                                return ne2000->tallycnt_1;

                        case 0xf: // CNTR2
                                return ne2000->tallycnt_2;
                        }

                        return 0;

                case 0x01:
#ifdef NE2000_DEBUG
                        pclog("page 1 read from port %04x\n", address);
#endif
                        switch (address) {
                        case 0x1: // PAR0-5
                        case 0x2:
                        case 0x3:
                        case 0x4:
                        case 0x5:
                        case 0x6:
                                return ne2000->physaddr[address - 1];

                        case 0x7: // CURR
#ifdef NE2000_DEBUG
                                pclog("returning current page: %02x\n", (ne2000->curr_page));
#endif
                                return ne2000->curr_page;

                        case 0x8: // MAR0-7
                        case 0x9:
                        case 0xa:
                        case 0xb:
                        case 0xc:
                        case 0xd:
                        case 0xe:
                        case 0xf:
                                return ne2000->mchash[address - 8];
                        }

                        return 0;

                case 0x02:
#ifdef NE2000_DEBUG
                        pclog("page 2 read from port %04x\n", address);
#endif
                        switch (address) {
                        case 0x1: // PSTART
                                return (ne2000->page_start);

                        case 0x2: // PSTOP
                                return ne2000->page_stop;

                        case 0x3: // Remote Next-packet pointer
                                return ne2000->rempkt_ptr;

                        case 0x4: // TPSR
                                return ne2000->tx_page_start;

                        case 0x5: // Local Next-packet pointer
                                return ne2000->localpkt_ptr;

                        case 0x6: // Address counter (upper)
                                return ne2000->address_cnt >> 8;

                        case 0x7: // Address counter (lower)
                                return ne2000->address_cnt & 0xff;

                        case 0x8: // Reserved
                        case 0x9:
                        case 0xa:
                        case 0xb:
#ifdef NE2000_DEBUG
                                pclog("reserved read - page 2, 0x%02x\n", address);
#endif
                                break;

                        case 0xc: // RCR
                                return ((ne2000->RCR.monitor << 5) | (ne2000->RCR.promisc << 4) | (ne2000->RCR.multicast << 3) |
                                        (ne2000->RCR.broadcast << 2) | (ne2000->RCR.runts_ok << 1) | (ne2000->RCR.errors_ok));

                        case 0xd: // TCR
                                return ((ne2000->TCR.coll_prio << 4) | (ne2000->TCR.ext_stoptx << 3) |
                                        ((ne2000->TCR.loop_cntl & 0x3) << 1) | (ne2000->TCR.crc_disable));

                        case 0xe: // DCR
                                return (((ne2000->DCR.fifo_size & 0x3) << 5) | (ne2000->DCR.auto_rx << 4) |
                                        (ne2000->DCR.loop << 3) | (ne2000->DCR.longaddr << 2) | (ne2000->DCR.endian << 1) |
                                        (ne2000->DCR.wdsize));

                        case 0xf: // IMR
                                return ((ne2000->IMR.rdma_inte << 6) | (ne2000->IMR.cofl_inte << 5) |
                                        (ne2000->IMR.overw_inte << 4) | (ne2000->IMR.txerr_inte << 3) |
                                        (ne2000->IMR.rxerr_inte << 2) | (ne2000->IMR.tx_inte << 1) | (ne2000->IMR.rx_inte));
                        }
                        break;

                case 0x03:
                        if (ne2000->type != NE2000_RTL8029AS)
                                fatal("ne2000 unknown value of pgsel in read - %d\n", ne2000->CR.pgsel);
#ifdef NE2000_DEBUG
                        pclog("page 3 read from port %04x\n", address);
#endif
                        switch (address) {
                        case 0x1: /*9346CR*/
                                return ne2000->_9346cr;

                        case 0x3:            /*CONFIG0*/
                                return 0x00; /*Cable not BNC*/

                        case 0x5:                              /*CONFIG2*/
                                return ne2000->config2 & 0xe0; /*No boot ROM*/

                        case 0x6: /*CONFIG3*/
                                return ne2000->config3 & 0x46;

                        case 0xe: /*8029ASID0*/
                                return 0x29;

                        case 0xf: /*8029ASID1*/
                                return 0x08;
                        }

                        pclog("reserved read - page 3, 0x%02x\n", address);
                        break;
                }
        }

        return ret;
}

//
// write_handler/write - i/o 'catcher' function called from BOCHS
// mainline when the CPU attempts a write in the i/o space registered
// by this ne2000 instance
//
void ne2000_write(uint16_t address, uint8_t value, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
#ifdef NE2000_DEBUG
        pclog("write address %x, val=%x\n", address, value);
#endif
        address &= 0xf;

        //
        // The high 16 bytes of i/o space are for the ne2000 asic -
        //  the low 16 bytes are for the DS8390, with the current
        //  page being selected by the PS0,PS1 registers in the
        //  command register
        //
        if (address == 0x00) {
#ifdef NE2000_DEBUG
                pclog("wrote 0x%02x to CR\n", value);
#endif
                // Validate remote-DMA
                if ((value & 0x38) == 0x00) {
#ifdef NE2000_DEBUG
                        pclog("CR write - invalid rDMA value 0\n");
#endif
                        value |= 0x20; /* dma_cmd == 4 is a safe default */
                                       // value = 0x22; /* dma_cmd == 4 is a safe default */
                }

                // Check for s/w reset
                if (value & 0x01) {
                        ne2000->ISR.reset = 1;
                        ne2000->CR.stop = 1;
                } else
                        ne2000->CR.stop = 0;

                ne2000->CR.rdma_cmd = (value & 0x38) >> 3;

                // If start command issued, the RST bit in the ISR
                // must be cleared
                if ((value & 0x02) && !ne2000->CR.start)
                        ne2000->ISR.reset = 0;

                ne2000->CR.start = ((value & 0x02) == 0x02);
                ne2000->CR.pgsel = (value & 0xc0) >> 6;

                // Check for send-packet command
                if (ne2000->CR.rdma_cmd == 3) {
                        // Set up DMA read from receive ring
                        ne2000->remote_start = ne2000->remote_dma = ne2000->bound_ptr * 256;
                        ne2000->remote_bytes = *((uint16_t *)&ne2000->mem[ne2000->bound_ptr * 256 + 2 - BX_NE2K_MEMSTART]);
#ifdef NE2000_DEBUG
                        pclog("Sending buffer #x%x length %d\n", ne2000->remote_start, ne2000->remote_bytes);
#endif
                }

                // Check for start-tx
                if ((value & 0x04) && ne2000->TCR.loop_cntl) {
                        // loopback mode
                        if (ne2000->TCR.loop_cntl != 1) {
#ifdef NE2000_DEBUG
                                pclog("Loop mode %d not supported.\n", ne2000->TCR.loop_cntl);
#endif
                        } else {
                                ne2000_rx_frame(ne2000, &ne2000->mem[ne2000->tx_page_start * 256 - BX_NE2K_MEMSTART],
                                                ne2000->tx_bytes);

                                // do a TX interrupt
                                // Generate an interrupt if not masked and not one in progress
                                if (ne2000->IMR.tx_inte && !ne2000->ISR.pkt_tx) {
                                        // LOG_MSG("tx complete interrupt");
                                        ne2000_raise_irq(ne2000);
                                }
                                ne2000->ISR.pkt_tx = 1;
                        }
                } else if (value & 0x04) {
                        // start-tx and no loopback
#ifdef NE2000_DEBUG
                        if (ne2000->CR.stop || !ne2000->CR.start)
                                pclog("CR write - tx start, dev in reset\n");

                        if (ne2000->tx_bytes == 0)
                                pclog("CR write - tx start, tx bytes == 0\n");
#endif
                        // Send the packet to the system driver
                        /* TODO: Transmit packet */
                        // BX_NE2K_THIS ethdev->sendpkt(& ne2000->mem[ne2000->tx_page_start*256 - BX_NE2K_MEMSTART],
                        // ne2000->tx_bytes); pcap_sendpacket(adhandle,&ne2000->mem[ne2000->tx_page_start*256 - BX_NE2K_MEMSTART],
                        // ne2000->tx_bytes);
                        if (net_is_slirp) {
                                slirp_input(&ne2000->mem[ne2000->tx_page_start * 256 - BX_NE2K_MEMSTART], ne2000->tx_bytes);
#ifdef NE2000_DEBUG
                                pclog("ne2000 slirp sending packet\n");
#endif
                        }
#ifdef USE_PCAP_NETWORKING
                        if (net_is_pcap && net_pcap != NULL) {
                                pcap_sendpacket(net_pcap, &ne2000->mem[ne2000->tx_page_start * 256 - BX_NE2K_MEMSTART],
                                                ne2000->tx_bytes);
#ifdef NE2000_DEBUG
                                pclog("ne2000 pcap sending packet\n");
#endif
                        }
#endif
                        ne2000_tx_event(value, ne2000);
                        // Schedule a timer to trigger a tx-complete interrupt
                        // The number of microseconds is the bit-time / 10.
                        // The bit-time is the preamble+sfd (64 bits), the
                        // inter-frame gap (96 bits), the CRC (4 bytes), and the
                        // the number of bits in the frame (s.tx_bytes * 8).
                        //

                        /* TODO: Code transmit timer */
                        /*
                        bx_pc_system.activate_timer(ne2000->tx_timer_index,
                                (64 + 96 + 4*8 + ne2000->tx_bytes*8)/10,
                        0); // not continuous
                        */
                } // end transmit-start branch

                // Linux probes for an interrupt by setting up a remote-DMA read
                // of 0 bytes with remote-DMA completion interrupts enabled.
                // Detect this here
                if (ne2000->CR.rdma_cmd == 0x01 && ne2000->CR.start && ne2000->remote_bytes == 0) {
                        ne2000->ISR.rdma_done = 1;
                        if (ne2000->IMR.rdma_inte) {
                                ne2000_raise_irq(ne2000);
                                // DEV_pic_raise_irq(ne2000->base_irq);
                        }
                }
        } else {
                switch (ne2000->CR.pgsel) {
                case 0x00:
#ifdef NE2000_DEBUG
                        pclog("page 0 write to port %04x\n", address);
#endif
                        // It appears to be a common practice to use outw on page0 regs...

                        switch (address) {
                        case 0x1: // PSTART
                                ne2000->page_start = value;
                                break;

                        case 0x2: // PSTOP
                                // BX_INFO(("Writing to PSTOP: %02x", value));
                                ne2000->page_stop = value;
                                break;

                        case 0x3: // BNRY
                                ne2000->bound_ptr = value;
                                break;

                        case 0x4: // TPSR
                                ne2000->tx_page_start = value;
                                break;

                        case 0x5: // TBCR0
                                // Clear out low byte and re-insert
                                ne2000->tx_bytes &= 0xff00;
                                ne2000->tx_bytes |= (value & 0xff);
                                break;

                        case 0x6: // TBCR1
                                // Clear out high byte and re-insert
                                ne2000->tx_bytes &= 0x00ff;
                                ne2000->tx_bytes |= ((value & 0xff) << 8);
                                break;

                        case 0x7:              // ISR
                                value &= 0x7f; // clear RST bit - status-only bit
                                // All other values are cleared iff the ISR bit is 1
                                ne2000->ISR.pkt_rx &= ~((int)((value & 0x01) == 0x01));
                                ne2000->ISR.pkt_tx &= ~((int)((value & 0x02) == 0x02));
                                ne2000->ISR.rx_err &= ~((int)((value & 0x04) == 0x04));
                                ne2000->ISR.tx_err &= ~((int)((value & 0x08) == 0x08));
                                ne2000->ISR.overwrite &= ~((int)((value & 0x10) == 0x10));
                                ne2000->ISR.cnt_oflow &= ~((int)((value & 0x20) == 0x20));
                                ne2000->ISR.rdma_done &= ~((int)((value & 0x40) == 0x40));
                                value = ((ne2000->ISR.rdma_done << 6) | (ne2000->ISR.cnt_oflow << 5) |
                                         (ne2000->ISR.overwrite << 4) | (ne2000->ISR.tx_err << 3) | (ne2000->ISR.rx_err << 2) |
                                         (ne2000->ISR.pkt_tx << 1) | (ne2000->ISR.pkt_rx));
                                value &= ((ne2000->IMR.rdma_inte << 6) | (ne2000->IMR.cofl_inte << 5) |
                                          (ne2000->IMR.overw_inte << 4) | (ne2000->IMR.txerr_inte << 3) |
                                          (ne2000->IMR.rxerr_inte << 2) | (ne2000->IMR.tx_inte << 1) | (ne2000->IMR.rx_inte));
                                if (value == 0)
                                        ne2000_lower_irq(ne2000);
                                // DEV_pic_lower_irq(ne2000->base_irq);
                                break;

                        case 0x8: // RSAR0
                                // Clear out low byte and re-insert
                                ne2000->remote_start &= 0xff00;
                                ne2000->remote_start |= (value & 0xff);
                                ne2000->remote_dma = ne2000->remote_start;
                                break;

                        case 0x9: // RSAR1
                                // Clear out high byte and re-insert
                                ne2000->remote_start &= 0x00ff;
                                ne2000->remote_start |= ((value & 0xff) << 8);
                                ne2000->remote_dma = ne2000->remote_start;
                                break;

                        case 0xa: // RBCR0
                                // Clear out low byte and re-insert
                                ne2000->remote_bytes &= 0xff00;
                                ne2000->remote_bytes |= (value & 0xff);
                                break;

                        case 0xb: // RBCR1
                                // Clear out high byte and re-insert
                                ne2000->remote_bytes &= 0x00ff;
                                ne2000->remote_bytes |= ((value & 0xff) << 8);
                                break;

                        case 0xc: // RCR
                                  // Check if the reserved bits are set
#ifdef NE2000_DEBUG
                                if (value & 0xc0)
                                        pclog("RCR write, reserved bits set\n");
#endif
                                // Set all other bit-fields
                                ne2000->RCR.errors_ok = ((value & 0x01) == 0x01);
                                ne2000->RCR.runts_ok = ((value & 0x02) == 0x02);
                                ne2000->RCR.broadcast = ((value & 0x04) == 0x04);
                                ne2000->RCR.multicast = ((value & 0x08) == 0x08);
                                ne2000->RCR.promisc = ((value & 0x10) == 0x10);
                                ne2000->RCR.monitor = ((value & 0x20) == 0x20);

                                // Monitor bit is a little suspicious...
#ifdef NE2000_DEBUG
                                if (value & 0x20)
                                        pclog("RCR write, monitor bit set!\n");
#endif
                                break;

                        case 0xd: // TCR
                                  // Check reserved bits
#ifdef NE2000_DEBUG
                                if (value & 0xe0)
                                        pclog("TCR write, reserved bits set\n");
#endif
                                // Test loop mode (not supported)
                                if (value & 0x06) {
                                        ne2000->TCR.loop_cntl = (value & 0x6) >> 1;
#ifdef NE2000_DEBUG
                                        pclog("TCR write, loop mode %d not supported\n", ne2000->TCR.loop_cntl);
#endif
                                } else
                                        ne2000->TCR.loop_cntl = 0;

                                // Inhibit-CRC not supported.
                                if (value & 0x01) {
                                        // fatal("ne2000 TCR write, inhibit-CRC not supported\n");
#ifdef NE2000_DEBUG
                                        pclog("ne2000 TCR write, inhibit-CRC not supported\n");
#endif
                                        return;
                                }

                                // Auto-transmit disable very suspicious
                                if (value & 0x08) {
                                        // fatal("ne2000 TCR write, auto transmit disable not supported\n");
#ifdef NE2000_DEBUG
                                        pclog("ne2000 TCR write, auto transmit disable not supported\n");
#endif
                                }

                                // Allow collision-offset to be set, although not used
                                ne2000->TCR.coll_prio = ((value & 0x08) == 0x08);
                                break;

                        case 0xe: // DCR
                                  // the loopback mode is not suppported yet
#ifdef NE2000_DEBUG
                                if (!(value & 0x08))
                                        pclog("DCR write, loopback mode selected\n");

                                // It is questionable to set longaddr and auto_rx, since they
                                // aren't supported on the ne2000. Print a warning and continue
                                if (value & 0x04)
                                        pclog("DCR write - LAS set ???\n");
                                if (value & 0x10)
                                        pclog("DCR write - AR set ???\n");
#endif
                                // Set other values.
                                ne2000->DCR.wdsize = ((value & 0x01) == 0x01);
                                ne2000->DCR.endian = ((value & 0x02) == 0x02);
                                ne2000->DCR.longaddr = ((value & 0x04) == 0x04); // illegal ?
                                ne2000->DCR.loop = ((value & 0x08) == 0x08);
                                ne2000->DCR.auto_rx = ((value & 0x10) == 0x10); // also illegal ?
                                ne2000->DCR.fifo_size = (value & 0x50) >> 5;
                                break;

                        case 0xf: // IMR
                                  // Check for reserved bit
#ifdef NE2000_DEBUG
                                if (value & 0x80)
                                        pclog("IMR write, reserved bit set\n");
#endif
                                // Set other values
                                ne2000->IMR.rx_inte = ((value & 0x01) == 0x01);
                                ne2000->IMR.tx_inte = ((value & 0x02) == 0x02);
                                ne2000->IMR.rxerr_inte = ((value & 0x04) == 0x04);
                                ne2000->IMR.txerr_inte = ((value & 0x08) == 0x08);
                                ne2000->IMR.overw_inte = ((value & 0x10) == 0x10);
                                ne2000->IMR.cofl_inte = ((value & 0x20) == 0x20);
                                ne2000->IMR.rdma_inte = ((value & 0x40) == 0x40);
                                value = ((ne2000->ISR.rdma_done << 6) | (ne2000->ISR.cnt_oflow << 5) |
                                         (ne2000->ISR.overwrite << 4) | (ne2000->ISR.tx_err << 3) | (ne2000->ISR.rx_err << 2) |
                                         (ne2000->ISR.pkt_tx << 1) | (ne2000->ISR.pkt_rx));
                                value &= ((ne2000->IMR.rdma_inte << 6) | (ne2000->IMR.cofl_inte << 5) |
                                          (ne2000->IMR.overw_inte << 4) | (ne2000->IMR.txerr_inte << 3) |
                                          (ne2000->IMR.rxerr_inte << 2) | (ne2000->IMR.tx_inte << 1) | (ne2000->IMR.rx_inte));
                                if (value)
                                        ne2000_raise_irq(ne2000);
                                else
                                        ne2000_lower_irq(ne2000);
                                break;
                        }
                        break;

                case 0x01:
#ifdef NE2000_DEBUG
                        pclog("page 1 w offset %04x\n", address);
#endif
                        switch (address) {
                        case 0x1: // PAR0-5
                        case 0x2:
                        case 0x3:
                        case 0x4:
                        case 0x5:
                        case 0x6:
                                ne2000->physaddr[address - 1] = value;
                                break;

                        case 0x7: // CURR
                                ne2000->curr_page = value;
                                break;

                        case 0x8: // MAR0-7
                        case 0x9:
                        case 0xa:
                        case 0xb:
                        case 0xc:
                        case 0xd:
                        case 0xe:
                        case 0xf:
                                ne2000->mchash[address - 8] = value;
                                break;
                        }
                        break;

                case 0x02:
#ifdef NE2000_DEBUG
                        if (address != 0)
                                pclog("page 2 write ?\n");
#endif
                        switch (address) {
                        case 0x1: // CLDA0
                                // Clear out low byte and re-insert
                                ne2000->local_dma &= 0xff00;
                                ne2000->local_dma |= (value & 0xff);
                                break;

                        case 0x2: // CLDA1
                                // Clear out high byte and re-insert
                                ne2000->local_dma &= 0x00ff;
                                ne2000->local_dma |= ((value & 0xff) << 8);
                                break;

                        case 0x3: // Remote Next-pkt pointer
                                ne2000->rempkt_ptr = value;
                                break;

                        case 0x4:
                                // fatal("page 2 write to reserved offset 4\n");
                                // OS/2 Warp can cause this to freak out.
#ifdef NE2000_DEBUG
                                pclog("ne2000 page 2 write to reserved offset 4\n");
#endif
                                break;

                        case 0x5: // Local Next-packet pointer
                                ne2000->localpkt_ptr = value;
                                break;

                        case 0x6: // Address counter (upper)
                                // Clear out high byte and re-insert
                                ne2000->address_cnt &= 0x00ff;
                                ne2000->address_cnt |= ((value & 0xff) << 8);
                                break;

                        case 0x7: // Address counter (lower)
                                // Clear out low byte and re-insert
                                ne2000->address_cnt &= 0xff00;
                                ne2000->address_cnt |= (value & 0xff);
                                break;

                        case 0x8:
                        case 0x9:
                        case 0xa:
                        case 0xb:
                        case 0xc:
                        case 0xd:
                        case 0xe:
                        case 0xf:
                                // fatal("page 2 write to reserved offset %0x\n", address);
#ifdef NE2000_DEBUG
                                pclog("ne2000 page 2 write to reserved offset %0x\n", address);
#endif
                        default:
                                break;
                        }
                        break;

                case 0x03:
                        if (ne2000->type != NE2000_RTL8029AS) {
                                pclog("ne2000 unknown value of pgsel in write - %d\n", ne2000->CR.pgsel);
                                break;
                        }
#ifdef NE2000_DEBUG
                        pclog("page 3 write to port %04x\n", address);
#endif
                        switch (address) {
                        case 0x1: /*9346CR*/
                                ne2000->_9346cr = value & 0xfe;
                                break;

                        case 0x5: /*CONFIG2*/
                                ne2000->config2 = value & 0xe0;
                                break;

                        case 0x6: /*CONFIG3*/
                                ne2000->config3 = value & 0x46;
                                break;

                        case 0x9: /*HLTCLK*/
                                break;

                        default:
                                pclog("reserved write - page 3, 0x%02x\n", address);
                                break;
                        }
                        break;
                }
        }
}

/*
 * mcast_index() - return the 6-bit index into the multicast
 * table. Stolen unashamedly from FreeBSD's if_ed.c
 */
static int mcast_index(const void *dst) {
#define POLYNOMIAL 0x04c11db6
        unsigned long crc = 0xffffffffL;
        int carry, i, j;
        unsigned char b;
        unsigned char *ep = (unsigned char *)dst;

        for (i = 6; --i >= 0;) {
                b = *ep++;
                for (j = 8; --j >= 0;) {
                        carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01);
                        crc <<= 1;
                        b >>= 1;
                        if (carry)
                                crc = ((crc ^ POLYNOMIAL) | carry);
                }
        }
        return crc >> 26;
#undef POLYNOMIAL
}

/*
 * rx_frame() - called by the platform-specific code when an
 * ethernet frame has been received. The destination address
 * is tested to see if it should be accepted, and if the
 * rx ring has enough room, it is copied into it and
 * the receive process is updated
 */
void ne2000_rx_frame(void *p, const void *buf, int io_len) {
        ne2000_t *ne2000 = (ne2000_t *)p;

        int pages;
        int avail;
        int idx;
        int nextpage;
        uint8_t pkthdr[4];
        uint8_t *pktbuf = (uint8_t *)buf;
        uint8_t *startptr;
        static uint8_t bcast_addr[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};

#ifdef NE2000_DEBUG
        if (io_len != 60)
                pclog("rx_frame with length %d\n", io_len);
#endif
        // LOG_MSG("stop=%d, pagestart=%x, dcr_loop=%x, tcr_loopcntl=%x",
        //	ne2000->CR.stop, ne2000->page_start,
        //	ne2000->DCR.loop, ne2000->TCR.loop_cntl);
        if ((ne2000->CR.stop != 0) ||
		(ne2000->page_start == 0) /*||
                ((ne2000->DCR.loop == 0) &&
                (ne2000->TCR.loop_cntl != 0))*/)
                return;

        // Add the pkt header + CRC to the length, and work
        // out how many 256-byte pages the frame would occupy
        pages = (io_len + 4 + 4 + 255) / 256;

        if (ne2000->curr_page < ne2000->bound_ptr)
                avail = ne2000->bound_ptr - ne2000->curr_page;
        else
                avail = (ne2000->page_stop - ne2000->page_start) - (ne2000->curr_page - ne2000->bound_ptr);

        // Avoid getting into a buffer overflow condition by not attempting
        // to do partial receives. The emulation to handle this condition
        // seems particularly painful.
        if ((avail < pages)
#if BX_NE2K_NEVER_FULL_RING
            || (avail == pages)
#endif
        ) {
#ifdef NE2000_DEBUG
                pclog("no space\n");
#endif
                return;
        }

        if ((io_len < 40 /*60*/) && !ne2000->RCR.runts_ok) {
#ifdef NE2000_DEBUG
                pclog("rejected small packet, length %d\n", io_len);
#endif
                return;
        }
        // some computers don't care...
        if (io_len < 60)
                io_len = 60;

        // Do address filtering if not in promiscuous mode
        if (!ne2000->RCR.promisc) {
                if (!memcmp(buf, bcast_addr, 6)) {
                        if (!ne2000->RCR.broadcast)
                                return;
                } else if (pktbuf[0] & 0x01) {
                        if (!ne2000->RCR.multicast)
                                return;
                        idx = mcast_index(buf);
                        if (!(ne2000->mchash[idx >> 3] & (1 << (idx & 0x7))))
                                return;
                } else if (0 != memcmp(buf, ne2000->physaddr, 6))
                        return;
        }
#ifdef NE2000_DEBUG
        else
                pclog("rx_frame promiscuous receive\n");

        pclog("rx_frame %d to %x:%x:%x:%x:%x:%x from %x:%x:%x:%x:%x:%x\n", io_len, pktbuf[0], pktbuf[1], pktbuf[2], pktbuf[3],
              pktbuf[4], pktbuf[5], pktbuf[6], pktbuf[7], pktbuf[8], pktbuf[9], pktbuf[10], pktbuf[11]);
#endif
        nextpage = ne2000->curr_page + pages;
        if (nextpage >= ne2000->page_stop)
                nextpage -= ne2000->page_stop - ne2000->page_start;

        // Setup packet header
        pkthdr[0] = 0; // rx status - old behavior
        pkthdr[0] = 1; // Probably better to set it all the time
        // rather than set it to 0, which is clearly wrong.
        if (pktbuf[0] & 0x01)
                pkthdr[0] |= 0x20; // rx status += multicast packet

        pkthdr[1] = nextpage;            // ptr to next packet
        pkthdr[2] = (io_len + 4) & 0xff; // length-low
        pkthdr[3] = (io_len + 4) >> 8;   // length-hi

        // copy into buffer, update curpage, and signal interrupt if config'd
        startptr = &ne2000->mem[ne2000->curr_page * 256 - BX_NE2K_MEMSTART];
        if ((nextpage > ne2000->curr_page) || ((ne2000->curr_page + pages) == ne2000->page_stop)) {
                memcpy(startptr, pkthdr, 4);
                memcpy(startptr + 4, buf, io_len);
                ne2000->curr_page = nextpage;
        } else {
                int endbytes = (ne2000->page_stop - ne2000->curr_page) * 256;
                memcpy(startptr, pkthdr, 4);
                memcpy(startptr + 4, buf, endbytes - 4);
                startptr = &ne2000->mem[ne2000->page_start * 256 - BX_NE2K_MEMSTART];
                memcpy(startptr, (void *)(pktbuf + endbytes - 4), io_len - endbytes + 8);
                ne2000->curr_page = nextpage;
        }

        ne2000->RSR.rx_ok = 1;
        if (pktbuf[0] & 0x80)
                ne2000->RSR.rx_mbit = 1;

        ne2000->ISR.pkt_rx = 1;

        if (ne2000->IMR.rx_inte) {
                // LOG_MSG("packet rx interrupt");
                ne2000_raise_irq(ne2000);
                // DEV_pic_raise_irq(ne2000->base_irq);
        }
        // else LOG_MSG("no packet rx interrupt");
}

void ne2000_tx_timer(void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;

#ifdef NE2000_DEBUG
        pclog("tx_timer\n");
#endif
        ne2000->TSR.tx_ok = 1;
        // Generate an interrupt if not masked and not one in progress
        if (ne2000->IMR.tx_inte && !ne2000->ISR.pkt_tx) {
                // LOG_MSG("tx complete interrupt");
                ne2000_raise_irq(ne2000);
                // DEV_pic_raise_irq(ne2000->base_irq);
        }
        // else 	  LOG_MSG("no tx complete interrupt");
        ne2000->ISR.pkt_tx = 1;
        ne2000->tx_timer_active = 0;
}

static void ne2000_tx_event(int val, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
        ne2000_tx_timer(ne2000);
}

static void ne2000_pci_add(ne2000_t *ne2000) {
        io_sethandler(ne2000->base_addr, 0x0010, ne2000_read, NULL, NULL, ne2000_write, NULL, NULL, ne2000);
        io_sethandler(ne2000->base_addr + 0x10, 0x000f, ne2000_asic_read_b, ne2000_asic_read_w, NULL, ne2000_asic_write_b,
                      ne2000_asic_write_w, NULL, ne2000);
        io_sethandler(ne2000->base_addr + 0x1f, 0x0001, ne2000_reset_read, NULL, NULL, ne2000_reset_write, NULL, NULL, ne2000);
}

static void ne2000_pci_remove(ne2000_t *ne2000) {
        io_removehandler(ne2000->base_addr, 0x0010, ne2000_read, NULL, NULL, ne2000_write, NULL, NULL, ne2000);
        io_removehandler(ne2000->base_addr + 0x10, 0x000f, ne2000_asic_read_b, ne2000_asic_read_w, NULL, ne2000_asic_write_b,
                         ne2000_asic_write_w, NULL, ne2000);
        io_removehandler(ne2000->base_addr + 0x1f, 0x0001, ne2000_reset_read, NULL, NULL, ne2000_reset_write, NULL, NULL, ne2000);
}

static uint8_t rtl8029_pci_read(int func, int addr, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;

        if (func)
                return 0;

        //        pclog("RTL8029 PCI read %08X PC=%08x\n", addr, cpu_state.pc);

        switch (addr) {
        case 0x00:
                return 0xec; /*Realtek*/
        case 0x01:
                return 0x10;

        case 0x02:
                return 0x29; /*RTL8029AS*/
        case 0x03:
                return 0x80;

        case 0x04:
                return ne2000->pci_command;

        case 0x07:
                return 0x02;

        case 0x08:
                return 0; /*Revision ID*/
        case 0x09:
                return 0; /*Programming interface*/
        case 0x0a:
                return 0; /*Ethernet controller*/
        case 0x0b:
                return 0x02; /*Network controller*/

        case 0x10:
                return 0x01 | (ne2000->base_addr & 0xe0); /*memBaseAddr*/
        case 0x11:
                return ne2000->base_addr >> 8;
        case 0x12:
                return ne2000->base_addr >> 16;
        case 0x13:
                return ne2000->base_addr >> 24;

        case 0x2c:
                return 0xec; /*Subsystem vendor - Realtek*/
        case 0x2d:
                return 0x10;

        case 0x2e:
                return 0x29; /*Subsystem ID - RTL8029AS*/
        case 0x2f:
                return 0x80;

        case 0x3c:
                return ne2000->int_line;
        case 0x3d:
                return 0x01; /*INTA*/
        }
        return 0;
}

static void rtl8029_pci_write(int func, int addr, uint8_t val, void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;

        if (func)
                return;

        //        pclog("RTL8029 PCI write %04X %02X PC=%08x\n", addr, val, cpu_state.pc);

        switch (addr) {
        case 0x04:
                if (ne2000->pci_command & PCI_COMMAND_IO)
                        ne2000_pci_remove(ne2000);
                ne2000->pci_command = val & 3;
                if (ne2000->pci_command & PCI_COMMAND_IO)
                        ne2000_pci_add(ne2000);
                break;

        case 0x10:
                if (ne2000->pci_command & PCI_COMMAND_IO)
                        ne2000_pci_remove(ne2000);
                ne2000->base_addr = (ne2000->base_addr & 0xffffff00) | (val & 0xe0);
                if (ne2000->pci_command & PCI_COMMAND_IO)
                        ne2000_pci_add(ne2000);
                break;
        case 0x11:
                if (ne2000->pci_command & PCI_COMMAND_IO)
                        ne2000_pci_remove(ne2000);
                ne2000->base_addr = (ne2000->base_addr & 0xffff00e0) | (val << 8);
                if (ne2000->pci_command & PCI_COMMAND_IO)
                        ne2000_pci_add(ne2000);
                break;
        case 0x12:
                ne2000->base_addr = (ne2000->base_addr & 0xff00ffe0) | (val << 16);
                break;
        case 0x13:
                ne2000->base_addr = (ne2000->base_addr & 0x00ffffe0) | (val << 24);
                break;

        case 0x3c:
                ne2000->int_line = val;
                break;
        }
}

static void ne2000_poller(void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
        struct queuepacket *qp;
        const unsigned char *data;
#ifdef USE_PCAP_NETWORKING
        struct pcap_pkthdr h;
#endif
        if (net_is_slirp) {
                while (QueuePeek(slirpq) > 0) {
                        qp = QueueDelete(slirpq);
                        if ((ne2000->DCR.loop == 0) || (ne2000->TCR.loop_cntl != 0)) {
                                free(qp);
                                return;
                        }
                        ne2000_rx_frame(ne2000, &qp->data, qp->len);
#ifdef NE2000_DEBUG
                        pclog("ne2000 inQ:%d  got a %dbyte packet @%d\n", QueuePeek(slirpq), qp->len, qp);
#endif
                        free(qp);
                }
                fizz++;
                if (fizz > 1200) {
                        fizz = 0;
                        slirp_tic();
                }
        } // end slirp
#ifdef USE_PCAP_NETWORKING
        if (net_is_pcap && net_pcap != NULL) {
                data = pcap_next(net_pcap, &h);
                if (data == 0x0)
                        return;
                if ((memcmp(data + 6, maclocal, 6)) == 0)
                        pclog("ne2000 we just saw ourselves\n");
                else {
                        if ((ne2000->DCR.loop == 0) || (ne2000->TCR.loop_cntl != 0))
                                return;

#ifdef NE2000_DEBUG
                        pclog("ne2000 pcap received a frame %d bytes\n", h.caplen);
#endif
                        ne2000_rx_frame(ne2000, data, h.caplen);
                }
        }
#endif
}

void *ne2000_common_init() {
        struct in_addr myaddr;
        int rc;
        unsigned int macint[6];
        char *macstring;

        ne2000_t *ne2000 = malloc(sizeof(ne2000_t));
        memset(ne2000, 0, sizeof(ne2000_t));

        macstring = config_get_string(CFG_MACHINE, NULL, "macaddr", "");

        if (sscanf(macstring, "%02x:%02x:%02x:%02x:%02x:%02x", &macint[0], &macint[1], &macint[2], &macint[3], &macint[4],
                   &macint[5]) != 6) {
                maclocal[0] = 0xac;
                maclocal[1] = 0xde;
                maclocal[2] = 0x48;
                maclocal[3] = 0x88;
                maclocal[4] = 0xbb;
                maclocal[5] = 0xaa;
                pclog("ne2000: Using default MAC address (AC:DE:48:88:BB:AA)\n");
        } else {
                maclocal[0] = macint[0];
                maclocal[1] = macint[1];
                maclocal[2] = macint[2];
                maclocal[3] = macint[3];
                maclocal[4] = macint[4];
                maclocal[5] = macint[5];
                pclog("ne2000: Using MAC address from pcem.cfg: %s\n", macstring);
        }

        // net_type
        // 0 pcap
        // 1 slirp
        //
#ifdef USE_PCAP_NETWORKING
        net_is_slirp = (config_get_int(CFG_GLOBAL, NULL, "net_type", NET_SLIRP) == NET_SLIRP) ? 1 : 0;
        pclog("ne2000 pcap device %s\n", config_get_string(CFG_GLOBAL, NULL, "pcap_device", "nothing"));

        // Check that we have a string setup, otherwise turn pcap off
        if (!strcmp("nothing", config_get_string(CFG_GLOBAL, NULL, "pcap_device", "nothing")))
                net_is_pcap = 0;
        else if (net_is_slirp == 0)
                net_is_pcap = 1;
#else
        net_is_slirp = 1;
        net_is_pcap = 0;
#endif

        memcpy(ne2000->physaddr, maclocal, 6);

        ne2000_reset(BX_RESET_HARDWARE, ne2000);
        vlan_handler(ne2000_poller, ne2000);

        pclog("ne2000 init\tslirp is %d net_is_pcap is %d\n", net_is_slirp, net_is_pcap);

        // need a switch statment for more network types.

        if (net_is_slirp) {
                pclog("ne2000 initalizing SLiRP\n");
                net_is_pcap = 0;
                rc = slirp_init();
                pclog("ne2000 slirp_init returned: %d\n", rc);
                if (rc == 0) {
                        pclog("ne2000 slirp initalized!\n");
                        inet_aton("10.0.2.15", &myaddr);
                        // YES THIS NEEDS TO PULL FROM A CONFIG FILE... but for now.
                        rc = slirp_redir(0, 42323, myaddr, 23);
                        pclog("ne2000 slirp redir returned %d on port 42323 -> 23\n", rc);
                        rc = slirp_redir(0, 42380, myaddr, 80);
                        pclog("ne2000 slirp redir returned %d on port 42380 -> 80\n", rc);
                        rc = slirp_redir(0, 42443, myaddr, 443);
                        pclog("ne2000 slirp redir returned %d on port 42443 -> 443\n", rc);
                        rc = slirp_redir(0, 42322, myaddr, 22);
                        pclog("ne2000 slirp redir returned %d on port 42322 -> 22\n", rc);

                        // Kali
                        rc = slirp_redir(1, 2213, myaddr, 2213);
                        pclog("ne2000 slirp redir returned %d on port 2213 -> 2213\n", rc);
                        rc = slirp_redir(1, 2231, myaddr, 2231);
                        pclog("ne2000 slirp redir returned %d on port 2231 -> 2231\n", rc);
                        rc = slirp_redir(1, 2271, myaddr, 2271);
                        pclog("ne2000 slirp redir returned %d on port 2271 -> 2271\n", rc);

                        net_slirp_inited = 1;
                        slirpq = QueueCreate();
                        net_is_slirp = 1;
                        fizz = 0;
                        pclog("ne2000 slirpq is %x\n", &slirpq);
                } else {
                        net_slirp_inited = 0;
                        net_is_slirp = 0;
                }
        }
#ifdef USE_PCAP_NETWORKING
        if (net_is_pcap) { // pcap
                char errbuf[32768];

                pclog("ne2000 initalizing libpcap\n");
                net_is_slirp = 0;

                if (pcap_lib_version && pcap_open_live && pcap_sendpacket && pcap_setnonblock && pcap_next && pcap_close &&
                    pcap_getnonblock) {
                        pclog("ne2000 Pcap version [%s]\n", pcap_lib_version());

                        if ((net_pcap = pcap_open_live(config_get_string(CFG_GLOBAL, NULL, "pcap_device", "nothing"), 1518, 1, 15,
                                                       errbuf)) == 0) {
                                pclog("ne2000 pcap_open_live error on %s!\n",
                                      config_get_string(CFG_GLOBAL, NULL, "pcap_device", "whatever the ethernet is"));
                                net_is_pcap = 0;
                                return (ne2000); // YUCK!!!
                        }
                } else {
                        pclog("%d %d %d %d %d %d %d\n", pcap_lib_version, pcap_open_live, pcap_sendpacket, pcap_setnonblock,
                              pcap_next, pcap_close, pcap_getnonblock);
                        net_is_pcap = 1;
                }

                // Time to check that we are in non-blocking mode.
                rc = pcap_getnonblock(net_pcap, errbuf);
                pclog("ne2000 pcap is currently in %s mode\n", rc ? "non-blocking" : "blocking");
                switch (rc) {
                case 0:
                        pclog("ne2000 Setting interface to non-blocking mode..");
                        rc = pcap_setnonblock(net_pcap, 1, errbuf);
                        if (rc == 0) {
                                pclog("..");
                                rc = pcap_getnonblock(net_pcap, errbuf);
                                if (rc == 1) {
                                        pclog("..!", rc);
                                        net_is_pcap = 1;
                                } else {
                                        pclog("\tunable to set pcap into non-blocking mode!\nContinuining without pcap.\n");
                                        net_is_pcap = 0;
                                }
                        } else {
                                pclog("There was an unexpected error of [%s]\n\nexiting.\n", errbuf);
                                net_is_pcap = 0;
                        }
                        pclog("\n");
                        break;
                case 1:
                        pclog("non blocking\n");
                        break;
                default:
                        pclog("this isn't right!!!\n");
                        net_is_pcap = 0;
                        break;
                }
                if (net_is_pcap) {
                        if (pcap_compile && pcap_setfilter) {
                                struct bpf_program fp;
                                char filter_exp[255];

                                pclog("ne2000 Building packet filter...");
                                sprintf(filter_exp,
                                        "( ((ether dst ff:ff:ff:ff:ff:ff) or (ether dst %02x:%02x:%02x:%02x:%02x:%02x)) and not "
                                        "(ether src %02x:%02x:%02x:%02x:%02x:%02x) )",
                                        maclocal[0], maclocal[1], maclocal[2], maclocal[3], maclocal[4], maclocal[5], maclocal[0],
                                        maclocal[1], maclocal[2], maclocal[3], maclocal[4], maclocal[5]);

                                // I'm doing a MAC level filter so TCP/IP doesn't matter.
                                if (pcap_compile(net_pcap, &fp, filter_exp, 0, 0xffffffff) == -1) {
                                        pclog("\nne2000 Couldn't compile filter\n");
                                } else {
                                        pclog("...");
                                        if (pcap_setfilter(net_pcap, &fp) == -1) {
                                                pclog("\nError installing pcap filter.\n");
                                        } else {
                                                pclog("...!\n");
                                        }
                                }
                                pclog("ne2000 Using filter\t[%s]\n", filter_exp);
                        } else {
                                pclog("ne2000 Your platform lacks pcap_compile & pcap_setfilter\n");
                                net_is_pcap = 0;
                        }
                        pclog("ne2000 net_is_pcap is %d and net_pcap is %x\n", net_is_pcap, net_pcap);
                }
        } // end pcap setup
#endif
        pclog("ne2000 is_slirp %d is_pcap %d\n", net_is_slirp, net_is_pcap);

        return ne2000;
}

void *ne2000_init() {
        ne2000_t *ne2000 = ne2000_common_init();
        uint16_t addr;

        ne2000->type = NE2000_NE2000;

        ne2000_setirq(ne2000, device_get_config_int("irq"));

        addr = device_get_config_int("addr");
        io_sethandler(addr, 0x0010, ne2000_read, NULL, NULL, ne2000_write, NULL, NULL, ne2000);
        io_sethandler(addr + 0x10, 0x0010, ne2000_asic_read_b, ne2000_asic_read_w, NULL, ne2000_asic_write_b, ne2000_asic_write_w,
                      NULL, ne2000);
        io_sethandler(addr + 0x1f, 0x0001, ne2000_reset_read, NULL, NULL, ne2000_reset_write, NULL, NULL, ne2000);

        return ne2000;
}

void *rtl8029_init() {
        ne2000_t *ne2000 = ne2000_common_init();

        ne2000->is_pci = 1;
        ne2000->type = NE2000_RTL8029AS;

        ne2000->card = pci_add(rtl8029_pci_read, rtl8029_pci_write, ne2000);

        ne2000_setirq(ne2000, NE2000_PCI_IRQ);

        return ne2000;
}

void ne2000_close(void *p) {
        ne2000_t *ne2000 = (ne2000_t *)p;
        free(ne2000);
        if (net_is_slirp) {
                QueueDestroy(slirpq);
                slirp_exit(0);
                net_slirp_inited = 0;
                pclog("ne2000 exiting slirp\n");
        }
#ifdef USE_PCAP_NETWORKING
        if (net_is_pcap && net_pcap != NULL) {
                pcap_close(net_pcap);
                pclog("ne2000 closing pcap\n");
        }
#endif
        pclog("ne2000 close\n");
}

static device_config_t ne2000_config[] = {{.name = "addr",
                                           .description = "Address",
                                           .type = CONFIG_BINARY,
                                           .type = CONFIG_SELECTION,
                                           .selection = {{.description = "0x280", .value = 0x280},
                                                         {.description = "0x300", .value = 0x300},
                                                         {.description = "0x320", .value = 0x320},
                                                         {.description = "0x340", .value = 0x340},
                                                         {.description = "0x360", .value = 0x360},
                                                         {.description = "0x380", .value = 0x380},
                                                         {.description = ""}},
                                           .default_int = 0x300},
                                          {.name = "irq",
                                           .description = "IRQ",
                                           .type = CONFIG_SELECTION,
                                           .selection = {{.description = "IRQ 3", .value = 3},
                                                         {.description = "IRQ 5", .value = 5},
                                                         {.description = "IRQ 7", .value = 7},
                                                         {.description = "IRQ 10", .value = 10},
                                                         {.description = "IRQ 11", .value = 11},
                                                         {.description = "IRQ 12", .value = 12},
                                                         {.description = ""}},
                                           .default_int = 10},
                                          {.type = -1}};

device_t ne2000_device = {"Novell NE2000", 0, ne2000_init, ne2000_close, NULL, NULL, NULL, NULL, ne2000_config};

device_t rtl8029as_device = {"Realtek RTL8029AS", DEVICE_PCI, rtl8029_init, ne2000_close, NULL, NULL, NULL, NULL, NULL};

// SLIRP stuff
int slirp_can_output(void) { return net_slirp_inited; }

void slirp_output(const unsigned char *pkt, int pkt_len) {
        struct queuepacket *p;
        p = (struct queuepacket *)malloc(sizeof(struct queuepacket));
        p->len = pkt_len;
        memcpy(p->data, pkt, pkt_len);
        QueueEnter(slirpq, p);
#ifdef NE2000_DEBUG
        pclog("ne2000 slirp_output %d @%d\n", pkt_len, p);
#endif
}

// Instead of calling this and crashing some times
// or experencing jitter, this is called by the
// 60Hz clock which seems to do the job.
void slirp_tic() {
        int ret2, nfds;
        struct timeval tv;
        fd_set rfds, wfds, xfds;
        int timeout;
        nfds = -1;

        if (net_slirp_inited) {
                FD_ZERO(&rfds);
                FD_ZERO(&wfds);
                FD_ZERO(&xfds);
                timeout = slirp_select_fill(&nfds, &rfds, &wfds, &xfds); // this can crash

                if (timeout < 0)
                        timeout = 500;
                tv.tv_sec = 0;
                tv.tv_usec = timeout; // basilisk default 10000

                ret2 = select(nfds + 1, &rfds, &wfds, &xfds, &tv);
                if (ret2 >= 0) {
                        slirp_select_poll(&rfds, &wfds, &xfds);
                }
                // pclog("ne2000 slirp_tic()\n");
        } // end if slirp inited
}
