serdrv.c

这个是LINUX下的GDB调度工具的源码

    printf("[%d@%d] ", nread, rbindex);
#endif

    if (nread>0)
       rbindex = rbindex+nread;

    do {
      restatus = Angel_RxEngine(readbuf[c], &(dc->dc_packet), &rxstate);
#ifdef DO_TRACE
      printf("<%02X ",readbuf[c]);
      if (!(++c % 16))
          printf("\n");
#else
      c++;
#endif
    } while (c<rbindex &&
             ((restatus == RS_IN_PKT) || (restatus == RS_WAIT_PKT)));

#ifdef DO_TRACE
   if (c % 16)
        printf("\n");
#endif

    switch(restatus) {
      
      case RS_GOOD_PKT:
        ret_code = 1;
        /* fall through to: */

      case RS_BAD_PKT:
        /*
         * We now need to shuffle any left over data down to the
         * beginning of our private buffer ready to be used 
         *for the next packet 
         */
#ifdef DO_TRACE
        printf("SerialRead() processed %d, moving down %d\n", c, rbindex-c);
#endif
        if (c != rbindex) memmove((char *) readbuf, (char *) (readbuf+c),
                                  rbindex-c);
        rbindex -= c;
        break;

      case RS_IN_PKT:
      case RS_WAIT_PKT:
        rbindex = 0;            /* will have processed all we had */
        ret_code = 0;
        break;

      default:
#ifdef DEBUG
        printf("Bad re_status in serialRead()\n");
#endif
        break;
    }
  } else if (nread == 0)
    ret_code = 0;               /* nothing to read */
  else if (read_errno == ERRNO_FOR_BLOCKED_IO) /* nread < 0 */
    ret_code = 0;

#ifdef DEBUG
  if ((nread<0) && (read_errno!=ERRNO_FOR_BLOCKED_IO))
    perror("read() error in serialRead()");
#endif

  return ret_code;
}


static int SerialWrite(DriverCall *dc) {
  int nwritten = 0;
  te_status testatus = TS_IN_PKT;

  if (dc->dc_context == NULL) {
    Angel_TxEngineInit(&config, &(dc->dc_packet), &(wstate.txstate));
    wstate.wbindex = 0;
    dc->dc_context = &wstate;
  }

  while ((testatus == TS_IN_PKT) && (wstate.wbindex < MAXWRITESIZE))
  {
    /* send the raw data through the tx engine to escape and encapsulate */
    testatus = Angel_TxEngine(&(dc->dc_packet), &(wstate.txstate),
                              &(wstate.writebuf)[wstate.wbindex]);
    if (testatus != TS_IDLE) wstate.wbindex++;
  }

  if (testatus == TS_IDLE) {
#ifdef DEBUG
    printf("SerialWrite: testatus is TS_IDLE during preprocessing\n");
#endif
  }

#ifdef DO_TRACE
  { 
    int i = 0;

    while (i<wstate.wbindex)
    {
        printf(">%02X ",wstate.writebuf[i]);

        if (!(++i % 16))
            printf("\n");
    }
    if (i % 16)
        printf("\n");
  }
#endif

#ifdef COMPILING_ON_WINDOWS
  if (WriteSerial(wstate.writebuf, wstate.wbindex) == COM_OK)
  {
    nwritten = wstate.wbindex;
    if (pfnProgressCallback != NULL)
    {
      progressInfo.nWritten += nwritten;
      (*pfnProgressCallback)(&progressInfo);
    }
  }
  else
  {
      MessageBox(GetFocus(), "Write error\n", "Angel", MB_OK | MB_ICONSTOP);
      return -1;   /* SJ - This really needs to return a value, which is picked up in */
                   /*      DevSW_Read as meaning stop debugger but don't kill. */
  }
#else
  nwritten = Unix_WriteSerial(wstate.writebuf, wstate.wbindex);

  if (nwritten < 0) {
    nwritten=0;
  }
#endif

#ifdef DEBUG
  if (nwritten > 0)
    printf("Wrote %#04x bytes\n", nwritten);
#endif

  if ((unsigned) nwritten == wstate.wbindex && 
      (testatus == TS_DONE_PKT || testatus == TS_IDLE)) {

    /* finished sending the packet */

#ifdef DEBUG
    printf("SerialWrite: calling Angel_TxEngineInit after sending packet (len=%i)\n",wstate.wbindex);
#endif
    testatus = TS_IN_PKT;
    wstate.wbindex = 0;
    return 1;
  }
  else {
#ifdef DEBUG
    printf("SerialWrite: Wrote part of packet wbindex=%i, nwritten=%i\n",
           wstate.wbindex, nwritten);
#endif
   
    /*
     *  still some data left to send shuffle whats left down and reset
     * the ptr
     */
    memmove((char *) wstate.writebuf, (char *) (wstate.writebuf+nwritten),
            wstate.wbindex-nwritten);
    wstate.wbindex -= nwritten;
    return 0;
  }
  return -1;
}


static int serial_reset( void )
{
#ifdef DEBUG
    printf( "serial_reset\n" );
#endif

#ifdef COMPILING_ON_WINDOWS
    FlushSerial();
#else
    Unix_ResetSerial();
#endif

    return serial_set_params( &serial_defaults );
}


static int find_baud_rate( unsigned int *speed )
{
    static struct {
          unsigned int baud;
          int termiosValue;
    } possibleBaudRates[] = {
#if defined(__hpux)
        {115200,_B115200}, {57600,_B57600},
#else
#ifdef B115200
        {115200,B115200},
#endif
#ifdef B57600
	{57600,B57600},
#endif
#endif
#ifdef COMPILING_ON_WINDOWS
        {38400,CBR_38400}, {19200,CBR_19200}, {9600, CBR_9600}, {0,0}
#else
        {38400,B38400}, {19200,B19200}, {9600, B9600}, {0,0}
#endif
    };
    unsigned int i;

    /* look for lower or matching -- will always terminate at 0 end marker */
    for ( i = 0; possibleBaudRates[i].baud > *speed; ++i )
       /* do nothing */ ;

    if ( possibleBaudRates[i].baud > 0 )
       *speed = possibleBaudRates[i].baud;

    return possibleBaudRates[i].termiosValue;
}


static int serial_set_params( const ParameterConfig *config )
{
    unsigned int speed;
    int termios_value;

#ifdef DEBUG
    printf( "serial_set_params\n" );
#endif

    if ( ! Angel_FindParam( AP_BAUD_RATE, config, &speed ) )
    {
#ifdef DEBUG
        printf( "speed not found in config\n" );
#endif
        return DE_OKAY;
    }

    termios_value = find_baud_rate( &speed );
    if ( termios_value == 0 )
    {
#ifdef DEBUG
        printf( "speed not valid: %u\n", speed );
#endif
        return DE_OKAY;
    }

#ifdef DEBUG
    printf( "setting speed to %u\n", speed );
#endif

#ifdef COMPILING_ON_WINDOWS
    SetBaudRate((WORD)termios_value);
#else
    Unix_SetSerialBaudRate(termios_value);
#endif

    return DE_OKAY;
}


static int serial_get_user_params( ParameterOptions **p_options )
{
#ifdef DEBUG
    printf( "serial_get_user_params\n" );
#endif

    if ( user_options_set )
    {
        *p_options = &user_options;
    }
    else
    {
        *p_options = NULL;
    }

    return DE_OKAY;
}


static int serial_get_default_params( ParameterConfig **p_config )
{
#ifdef DEBUG
    printf( "serial_get_default_params\n" );
#endif

    *p_config = (ParameterConfig *) &serial_defaults;
    return DE_OKAY;
}


static int SerialIoctl(const int opcode, void *args) {

    int ret_code;

#ifdef DEBUG
    printf( "SerialIoctl: op %d arg %p\n", opcode, args ? args : "<NULL>");
#endif

    switch (opcode)
    {
       case DC_RESET:         
           ret_code = serial_reset();
           break;

       case DC_SET_PARAMS:     
           ret_code = serial_set_params((const ParameterConfig *)args);
           break;

       case DC_GET_USER_PARAMS:     
           ret_code = serial_get_user_params((ParameterOptions **)args);
           break;

       case DC_GET_DEFAULT_PARAMS:
           ret_code = serial_get_default_params((ParameterConfig **)args);
           break;

       default:               
           ret_code = DE_BAD_OP;
           break;
    }

  return ret_code;
}

DeviceDescr angel_SerialDevice = {
    "SERIAL",
    SerialOpen,
    SerialMatch,
    SerialClose,
    SerialRead,
    SerialWrite,
    SerialIoctl
};