if_ne2kd.c

一个简单的TCP IP协议栈程序

        // ***** 10. Take the NIC out of loopback mode (that means normal operation)
        OUTPORTB(PG0W_TCR, 0x00);
        PAUSE;

        // ***** 11. IF Resend = 1 THEN reissue a transmit
        if (Resend)
        {
            // Reissue transmit
            OUTPORTB(NIC_CR, CR_START | CR_NO_DMA | CR_TXP);
            PAUSE;
        }
    }else{
        PAUSE;
    }

    // ***** Restore NIC IMR
    OUTPORTB(PG0W_IMR, Imr);
    PAUSE;

    // ***** RETURN Success
    return rtn;
}


static u_short Ne2kTransmitReady(void)
{
  // ***** IF transmitting THEN RETURN FALSE
  if (INPORTB(NIC_CR) & CR_TXP) return FALSE;

  // ***** RETURN TRUE
  return TRUE;
}


int Ne2kTransmit(const u_char *packet, u_short length)
{
  int Timeout, Count;
  u_char Imr;
  u_char CrdaLow, CrdaHigh;

//    printf("Ne2kTransmit\n");

  // ***** IF transmitting THEN RETURN FALSE
  if (!Ne2kTransmitReady()) return FALSE;

  // ***** IF (length < 14) OR (length > 1514) THEN RETURN FALSE
  if ((length < 14) || (length > 1514)) return FALSE;

  // ***** Remember NIC IMR and disable interrupt from NIC (ATOMIC OPERATION!)
  DISABLE_INTERRUPTS;
  // Select PAGE 2
  OUTPORTB(NIC_CR, CR_PAGE2 | CR_NO_DMA | CR_START);
  PAUSE;
  // Read IMR register
  Imr = INPORTB(PG2R_IMR);
  PAUSE;
  // Select PAGE 0 again
  OUTPORTB(NIC_CR, CR_PAGE0 | CR_NO_DMA | CR_START);
  PAUSE;
  // Disable interrupts from NIC
  OUTPORTB(PG0W_IMR, 0x00);
  PAUSE;
  ENABLE_INTERRUPTS;

  // ***** Clear REMOTE DMA COMPLETE bit in ISR
  OUTPORTB(PG0W_ISR, ISR_RDC);
  PAUSE;

  // ***********************************************************************************
  // ***** Due to two non synchronized state machines in the NIC, you should always do a 
  // ***** Remote Read (called a dummy read) before a Remote Write.
  // ***** This is stated in the datasheet DP8390D/NS32490D NIC Network Interface Controller
  // ***** (July 1995) from National  Semiconductor. 

  // ***** 1. Set Remote Byte Count to a value > 0 and Remote Start Address to unused RAM 
  //          (like transmit start page - 1) (REMEMBER THESE VALUES!)
  CrdaLow = 0;
  CrdaHigh = TSTART_PG - 1;

  OUTPORTB(PG0W_RBCR0, 1);
  PAUSE;
  OUTPORTB(PG0W_RBCR1, 0);
  PAUSE;
  OUTPORTB(PG0W_RSAR0, CrdaLow);
  PAUSE;
  OUTPORTB(PG0W_RSAR1, CrdaHigh);
  PAUSE;

  // ***** 2. Issue the "dummy" Remote Read command
  OUTPORTB(NIC_CR, CR_START | CR_DMA_READ);
  PAUSE;

  // ***** 3. Read the current remote DMA address (CRDA) (both bytes)
  // ***** 4. Compare to previous CRDA value, if different go to step 6
  // ***** 5. Delay and go to step 3.
  // timeout < 100 === leave us with appr. 200us timeout (which is a lot)
  // (this timeout is not impl. in NS' datasheet, but it's better to be on the safe side)
  for (Timeout = 0; Timeout < 50; Timeout++)
  {
    if (CrdaLow != INPORTB(PG0R_CRDA0)) break;
    PAUSE;
    if (CrdaHigh != INPORTB(PG0R_CRDA1)) break;
    PAUSE;
  }

  // ***** 6. Setup for the Remote Write command
  // *****     Stop REMOTE DMA 
  OUTPORTB(NIC_CR, CR_START | CR_NO_DMA);
  PAUSE;

  // *****     Initialize Transmit Byte Count Registers to packet length and MIN. MIN_PACKET_SIZE bytes 
  if (length < MIN_PACKET_SIZE)
  { 
    // Padding required
    OUTPORTB(PG0W_TBCR0, MIN_PACKET_SIZE);
    PAUSE;
    OUTPORTB(PG0W_TBCR1, 0);
    PAUSE;
  }
  else
  { 
    // No padding required
    OUTPORTB(PG0W_TBCR0, (length & 0xFF));
    PAUSE;
    OUTPORTB(PG0W_TBCR1, ((length >> 8) & 0xFF) );
    PAUSE;
  }

  // ***** Update statistics (before making length an even value!)
  Statistics.BytesTransmitted += length;
  Statistics.PacketsTransmitted++;

  // *****     We use word transfer mode, so make length an even value
  length &= 0xfffe;
  length++;

  // *****     Initialize Remote Byte Count Register (DMA) to packet length 
  OUTPORTB(PG0W_RBCR0, (length & 0xFF));
  PAUSE;
  OUTPORTB(PG0W_RBCR1, ((length >> 8) & 0xFF));
  PAUSE;

  // *****     Initialize  Remote Start Address Register to address of NIC transmit buffer  
  OUTPORTB(PG0W_RSAR0, 0);
  PAUSE;
  OUTPORTB(PG0W_RSAR1, TSTART_PG);
  PAUSE;

  // ***** 7. Issue the Remote DMA WRITE 
  // *****     Start DMA Write
  OUTPORTB(NIC_CR, CR_START | CR_DMA_WRITE);
  PAUSE;

  // *****     Write data to NIC
  for (Count = 0; Count < length; Count += 2) OUTPORTW(NIC_DATAPORT, packet[Count] | (packet[Count+1] << 8));

  // ***** Wait for Remote DMA to complete (should be instantly, but we have to wait anyway)
  // timeout < 200 === leave us with appr. 200us timeout (which is a lot)
  // (this timeout is not impl. in NS' datasheet, but it's better to be on the safe side)
  for (Timeout = 0; Timeout < 200; Timeout++)
  {
    if (INPORTB(PG0R_ISR) & ISR_RDC) break;
    PAUSE;
  }

  // ***** Clear REMOTE DMA COMPLETE bit in ISR
  OUTPORTB(PG0W_ISR, ISR_RDC);
  PAUSE;

  // ***** Initialize Transmit Page Start Register
  OUTPORTB(PG0W_TPSR, TSTART_PG);
  PAUSE;

  // ***** Start transmission
  OUTPORTB(NIC_CR, CR_START | CR_NO_DMA | CR_TXP);
  PAUSE;

  // ***** Restore NIC IMR
  OUTPORTB(PG0W_IMR, Imr);
  PAUSE;

  // ***** RETURN TRUE
  return TRUE;
}

static void Ne2kTxNBuf(NBuf *pNBuf)
{
    u_short d;
    unsigned char *p_d;
    long l;
    int i;
    NBuf *n;

//    printf("TxNBuf:\n");

    n=pNBuf;
    l=pNBuf->len;
    p_d=pNBuf->data;
    i=0;
    while(n)
    {
        if(l==0)
        {
            // next nBuf
            n=n->nextBuf;
            if(n)
            {
                l=n->len;
                p_d=n->data;
            }
        }else{
            d=(d<<8)|*p_d++;
            l--;
            if(++i==2)
            {
                i=0;
                OUTPORTW(NIC_DATAPORT, d);
//                printf("0x%lx\n",d);
            }
        }
    }
    if(i)
    {
        // as we were writing words, we might have a single trailling byte, so just send it...
        d<<=8;
        OUTPORTW(NIC_DATAPORT, d);
//        printf("odd 0x%lx\n",d);
    }
}

//static u_char dbgseq=1;

static u_char Ne2kTxPacket(NBuf *pNBuf)
{
  int Timeout;
//  int Count;
  u_char Imr;
  u_char CrdaLow, CrdaHigh;
    u_short length;//,padding,lTx;

//    printf("Ne2kTxPacket\n");

    // ***** IF transmitting THEN RETURN FALSE
  if (!Ne2kTransmitReady()) return FALSE;

    length=nChainLen(pNBuf);

//    printf("Ne2kTxPacket: length=%d\n",length);

  // ***** IF (length < 14) OR (length > 1514) THEN RETURN FALSE
  if ((length < 14) || (length > 1514)) return FALSE;

  // ***** Remember NIC IMR and disable interrupt from NIC (ATOMIC OPERATION!)
  DISABLE_INTERRUPTS;
  // Select PAGE 2
  OUTPORTB(NIC_CR, CR_PAGE2 | CR_NO_DMA | CR_START);
  PAUSE;
  // Read IMR register
  Imr = INPORTB(PG2R_IMR);
  PAUSE;
  // Select PAGE 0 again
  OUTPORTB(NIC_CR, CR_PAGE0 | CR_NO_DMA | CR_START);
  PAUSE;
  // Disable interrupts from NIC
  OUTPORTB(PG0W_IMR, 0x00);
  PAUSE;
  ENABLE_INTERRUPTS;

  // ***** Clear REMOTE DMA COMPLETE bit in ISR
  OUTPORTB(PG0W_ISR, ISR_RDC);
  PAUSE;

  // ***********************************************************************************
  // ***** Due to two non synchronized state machines in the NIC, you should always do a
  // ***** Remote Read (called a dummy read) before a Remote Write.
  // ***** This is stated in the datasheet DP8390D/NS32490D NIC Network Interface Controller
  // ***** (July 1995) from National  Semiconductor.

  // ***** 1. Set Remote Byte Count to a value > 0 and Remote Start Address to unused RAM
  //          (like transmit start page - 1) (REMEMBER THESE VALUES!)
  CrdaLow = 0;
  CrdaHigh = TSTART_PG - 1;

  OUTPORTB(PG0W_RBCR0, 1);
  PAUSE;
  OUTPORTB(PG0W_RBCR1, 0);
  PAUSE;
  OUTPORTB(PG0W_RSAR0, CrdaLow);
  PAUSE;
  OUTPORTB(PG0W_RSAR1, CrdaHigh);
  PAUSE;

  // ***** 2. Issue the "dummy" Remote Read command
  OUTPORTB(NIC_CR, CR_START | CR_DMA_READ);
  PAUSE;

  // ***** 3. Read the current remote DMA address (CRDA) (both bytes)
  // ***** 4. Compare to previous CRDA value, if different go to step 6
  // ***** 5. Delay and go to step 3.
  // timeout < 100 === leave us with appr. 200us timeout (which is a lot)
  // (this timeout is not impl. in NS' datasheet, but it's better to be on the safe side)
  for (Timeout = 0; Timeout < 50; Timeout++)
  {
    if (CrdaLow != INPORTB(PG0R_CRDA0)) break;
    PAUSE;
    if (CrdaHigh != INPORTB(PG0R_CRDA1)) break;
    PAUSE;
  }

  // ***** 6. Setup for the Remote Write command
  // *****     Stop REMOTE DMA
  OUTPORTB(NIC_CR, CR_START | CR_NO_DMA);
  PAUSE;

  // *****     Initialize Transmit Byte Count Registers to packet length and MIN. MIN_PACKET_SIZE bytes
  if (length < MIN_PACKET_SIZE)
  {
//        printf("padding: length=%d, actual sent packet=%d\n",length,MIN_PACKET_SIZE);
//        padding=MIN_PACKET_SIZE-length;
//        length=MIN_PACKET_SIZE;

    // Padding required
    OUTPORTB(PG0W_TBCR0, MIN_PACKET_SIZE);
    PAUSE;
    OUTPORTB(PG0W_TBCR1, 0);
    PAUSE;
  }else{
//        padding=0;
//    }
    // No padding required
    OUTPORTB(PG0W_TBCR0, (length & 0xFF));
    PAUSE;
    OUTPORTB(PG0W_TBCR1, ((length >> 8) & 0xFF) );
    PAUSE;
  }

  // ***** Update statistics (before making length an even value!)
  Statistics.BytesTransmitted += length;
  Statistics.PacketsTransmitted++;

  // *****     We use word transfer mode, so make length an even value
  length += length&1;

  // *****     Initialize Remote Byte Count Register (DMA) to packet length
  OUTPORTB(PG0W_RBCR0, (length & 0xFF));
  PAUSE;
  OUTPORTB(PG0W_RBCR1, ((length >> 8) & 0xFF));
  PAUSE;

  // *****     Initialize  Remote Start Address Register to address of NIC transmit buffer
  OUTPORTB(PG0W_RSAR0, 0);
  PAUSE;
  OUTPORTB(PG0W_RSAR1, TSTART_PG);
  PAUSE;

  // ***** 7. Issue the Remote DMA WRITE
  // *****     Start DMA Write
  OUTPORTB(NIC_CR, CR_START | CR_DMA_WRITE);
  PAUSE;

  // *****     Write data to NIC
    Ne2kTxNBuf(pNBuf);

    // send padding
/*    while(padding>0)
    {
        padding-=2;
        OUTPORTW(NIC_DATAPORT,dbgseq);
    }
    dbgseq++;*/
  // ***** Wait for Remote DMA to complete (should be instantly, but we have to wait anyway)
  // timeout < 200 === leave us with appr. 200us timeout (which is a lot)
  // (this timeout is not impl. in NS' datasheet, but it's better to be on the safe side)
  for (Timeout = 0; Timeout < 200; Timeout++)
  {
    if (INPORTB(PG0R_ISR) & ISR_RDC) break;
    PAUSE;
  }

  // ***** Clear REMOTE DMA COMPLETE bit in ISR
  OUTPORTB(PG0W_ISR, ISR_RDC);
  PAUSE;

  // ***** Initialize Transmit Page Start Register
  OUTPORTB(PG0W_TPSR, TSTART_PG);
  PAUSE;

  // ***** Start transmission
  OUTPORTB(NIC_CR, CR_START | CR_NO_DMA | CR_TXP);
  PAUSE;

  // ***** Restore NIC IMR
  OUTPORTB(PG0W_IMR, Imr);
  PAUSE;

  // ***** RETURN TRUE
  return TRUE;
}


void Ne2kGetStatistics(Ne2kStatistics *statistics)