[Windows Mobile Development and Hacking General] mamaich:
The first entry point is DllMain. Then init function is called. Then open when your device is opened. If you have global classes with constructors - constructors are called before DllMain (I have not tested that), one of them may be the reason of crash.

The sample is in the link I gave in the prev. post. or here is a sample driver that is a wrapper around Serial_BTUR.dll

// Serial.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#include "Serial.h"
#include <psapi.h>
#include <Mmsystem.h>

struct HCI_
{
char *Text;
int Code;
} Cmds[]=
{
"HCI_NOP",0x0000,
"HCI_Inquiry",0x0401,
"HCI_Inquiry_Cancel",0x0402,
"HCI_Periodic_Inquiry_Mode",0x0403,
"HCI_Exit_Periodic_Inquiry_Mode",0x0404,
"HCI_Create_Connection",0x0405,
"HCI_Disconnect",0x0406,
"HCI_Add_SCO_Connection",0x0407,
"HCI_Accept_Connection_Request",0x0409,
"HCI_Reject_Connection_Request",0x040a,
"HCI_Link_Key_Request_Reply",0x040b,
"HCI_Link_Key_Request_Negative_Reply",0x040c,
"HCI_PIN_Code_Request_Reply",0x040d,
"HCI_PIN_Code_Request_Negative_Reply",0x040e,
"HCI_Change_Connection_Packet_Type",0x040f,
"HCI_Authentication_Requested",0x0411,
"HCI_Set_Connection_Encryption",0x0413,
"HCI_Change_Connection_Link_Key",0x0415,
"HCI_Master_Link_Key",0x0417,
"HCI_Remote_Name_Request",0x0419,
"HCI_Read_Remote_Supported_Features",0x041b,
"HCI_Read_Remote_Version_Information",0x041d,
"HCI_Read_Clock_Offset",0x041f,
"HCI_Hold_Mode",0x0801,
"HCI_Sniff_Mode",0x0803,
"HCI_Exit_Sniff_Mode",0x0804,
"HCI_Park_Mode",0x0805,
"HCI_Exit_Park_Mode",0x0806,
"HCI_QoS_Setup",0x0807,
"HCI_Role_Discovery",0x0809,
"HCI_Switch_Role",0x080b,
"HCI_Read_Link_Policy_Settings",0x080c,
"HCI_Write_Link_Policy_Settings",0x080d,
"HCI_Set_Event_Mask",0x0c01,
"HCI_Reset",0x0c03,
"HCI_Set_Event_Filter",0x0c05,
"HCI_Flush",0x0c08,
"HCI_Read_PIN_Type",0x0c09,
"HCI_Write_PIN_Type",0x0c0a,
"HCI_Create_New_Unit_Key",0x0c0b,
"HCI_Read_Stored_Link_Key",0x0c0d,
"HCI_Write_Stored_Link_Key",0x0c11,
"HCI_Delete_Stored_Link_Key",0x0c12,
"HCI_Change_Local_Name",0x0c13,
"HCI_Read_Local_Name",0x0c14,
"HCI_Read_Connection_Accept_Timeout",0x0c15,
"HCI_Write_Connection_Accept_Timeout",0x0c16,
"HCI_Read_Page_Timeout",0x0c17,
"HCI_Write_Page_Timeout",0x0c18,
"HCI_Read_Scan_Enable",0x0c19,
"HCI_Write_Scan_Enable",0x0c1a,
"HCI_Read_PageScan_Activity",0x0c1b,
"HCI_Write_PageScan_Activity",0x0c1c,
"HCI_Read_InquiryScan_Activity",0x0c1d,
"HCI_Write_InquiryScan_Activity",0x0c1e,
"HCI_Read_Authentication_Enable",0x0c1f,
"HCI_Write_Authentication_Enable",0x0c20,
"HCI_Read_Encryption_Mode",0x0c21,
"HCI_Write_Encryption_Mode",0x0c22,
"HCI_Read_Class_Of_Device",0x0c23,
"HCI_Write_Class_Of_Device",0x0c24,
"HCI_Read_Voice_Setting",0x0c25,
"HCI_Write_Voice_Setting",0x0c26,
"HCI_Read_Automatic_Flush_Timeout",0x0c27,
"HCI_Write_Automatic_Flush_Timeout",0x0c28,
"HCI_Read_Num_Broadcast_Retransmissions",0x0c29,
"HCI_Write_Num_Broadcast_Retransmissions",0x0c2a,
"HCI_Read_Hold_Mode_Activity",0x0c2b,
"HCI_Write_Hold_Mode_Activity",0x0c2c,
"HCI_Read_Transmit_Power_Level",0x0c2d,
"HCI_Read_SCO_Flow_Control_Enable",0x0c2e,
"HCI_Write_SCO_Flow_Control_Enable",0x0c2f,
"HCI_Set_Host_Controller_To_Host_Flow_Control",0x0c31,
"HCI_Host_Buffer_Size",0x0c33,
"HCI_Host_Number_Of_Completed_Packets",0x0c35,
"HCI_Read_Link_Supervision_Timeout",0x0c36,
"HCI_Write_Link_Supervision_Timeout",0x0c37,
"HCI_Read_Number_Of_Supported_IAC",0x0c38,
"HCI_Read_Current_IAC_LAP",0x0c39,
"HCI_Write_Current_IAC_LAP",0x0c3a,
"HCI_Read_Page_Scan_Period_Mode",0x0c3b,
"HCI_Write_Page_Scan_Period_Mode",0x0c3c,
"HCI_Read_Page_Scan_Mode",0x0c3d,
"HCI_Write_Page_Scan_Mode",0x0c3e,
"HCI_Read_Local_Version_Information",0x1001,
"HCI_Read_Local_Supported_Features",0x1003,
"HCI_Read_Buffer_Size",0x1005,
"HCI_Read_Country_Code",0x1007,
"HCI_Read_BD_ADDR",0x1009,
"HCI_Read_Failed_Contact_Counter",0x1401,
"HCI_Reset_Failed_Contact_Counter",0x1402,
"HCI_Get_Link_Quality",0x1403,
"HCI_Read_RSSI",0x1405,
"HCI_Read_Loopback_Mode",0x1801,
"HCI_Write_Loopback_Mode",0x1802,
"HCI_Enable_Device_Under_Test_Mode",0x1803,
0,0
},Events[]=
{
"HCI_Inquiry_Complete_Event",0x01,
"HCI_Inquiry_Result_Event",0x02,
"HCI_Connection_Complete_Event",0x03,
"HCI_Connection_Request_Event",0x04,
"HCI_Disconnection_Complete_Event",0x05,
"HCI_Authentication_Complete_Event",0x06,
"HCI_Remote_Name_Request_Complete_Event",0x07,
"HCI_Encryption_Change_Event",0x08,
"HCI_Change_Connection_Link_Key_Complete_Event",0x09,
"HCI_Master_Link_Key_Complete_Event",0x0a,
"HCI_Read_Remote_Supported_Features_Complete_Event",0x0b,
"HCI_Read_Remote_Version_Information_Complete_Event",0x0c,
"HCI_QoS_Setup_Complete_Event",0x0d,
"HCI_Command_Complete_Event",0x0e,
"HCI_Command_Status_Event",0x0f,
"HCI_Hardware_Error_Event",0x10,
"HCI_Flush_Occured_Event",0x11,
"HCI_Role_Change_Event",0x12,
"HCI_Number_Of_Completed_Packets_Event",0x13,
"HCI_Mode_Change_Event",0x14,
"HCI_Return_Link_Keys_Event",0x15,
"HCI_PIN_Code_Request_Event",0x16,
"HCI_Link_Key_Request_Event",0x17,
"HCI_Link_Key_Notification_Event",0x18,
"HCI_Loopback_Command_Event",0x19,
"HCI_Data_Buffer_Overflow_Event",0x1a,
"HCI_Max_Slots_Change_Event",0x1b,
"HCI_Read_Clock_Offset_Complete_Event",0x1c,
"HCI_Connection_Packet_Type_Changed_Event",0x1d,
"HCI_QoS_Violation_Event",0x1e,
"HCI_Page_Scan_Mode_Change_Event",0x1f,
"HCI_Page_Scan_Repetition_Mode_Change_Event",0x20,
0,0
};

char *FindEvent(int id)
{
for(int i=0; Events[i].Text;i++)
{
if(Events[i].Code==id)
return Events[i].Text;
}
return "HCI_???";
}

char *FindMessage(int id)
{
for(int i=0; Cmds[i].Text;i++)
{
if(Cmds[i].Code==id)
return Cmds[i].Text;
}
return "HCI_???";
}

typedef BOOL t_COM_Deinit(DWORD dwOpenData);

typedef BOOL t_COM_IOControl(
DWORD dwOpenData,
DWORD dwCode,
PBYTE pBufIn,
DWORD dwLenIn,
PBYTE pBufOut,
DWORD dwLenOut,
PDWORD pdwActualOut
);

typedef HANDLE t_COM_Init(
ULONG Identifier
);

typedef HANDLE t_COM_Open(
HANDLE pContext,
DWORD AccessCode,
DWORD ShareMode
);

typedef BOOL t_COM_PowerDown(
HANDLE pContext
);

typedef BOOL t_COM_PowerUp(
HANDLE pContext
);

typedef ULONG t_COM_Read(
HANDLE pContext,
PUCHAR pTargetBuffer,
ULONG BufferLength
);

typedef ULONG t_COM_Write(
HANDLE COM_Write,
PUCHAR pSourceBytes,
ULONG NumberOfBytes
);

typedef BOOL t_COM_Close(
DWORD pContext
);

t_COM_Deinit *_COM_Deinit=0;
t_COM_IOControl *_COM_IOControl=0;
t_COM_Init *_COM_Init=0;
t_COM_Open *_COM_Open=0;
t_COM_PowerDown *_COM_PowerDown=0;
t_COM_PowerUp *_COM_PowerUp=0;
t_COM_Read *_COM_Read=0;
t_COM_Write *_COM_Write=0;
t_COM_Close *_COM_Close=0;

HANDLE hEvent=0;

char* Dump(const unsigned char *Buff, int count)
{
static char Out[65536];
char* p=Out;
if(count==0)
{
p+=sprintf(p,"\n");
return Out;
}
{
bool OnlyASCII=true;
for(int i=0; i<count; i++)
if((Buff[i]&255)<32||Buff[i]==127)
{
if((i==count-1 && Buff[i]==0)||Buff[i]==0x0d||Buff[i]==0x0a||Buff[i]==9)
continue;
OnlyASCII=false;
break;
}
if(OnlyASCII)
{
p+=sprintf(p,"--- Plain text\n");
for(int i=0; i<count; i++)
if(Buff[i]!='\r')
p+=sprintf(p,"%c",Buff[i]);
// if(Buff[count-1]!='\n')
// fprintf(Log,"\n");
p+=sprintf(p,"\n--- End of text\n\n");
return Out;
}
int Pos=0;
char OBuff[3*16+2+1];
char Str[17];
for(i=0; i<(count+15)/16; i++)
{
for(int j=0; j<16; j++,Pos++)
{
if(Pos<count)
{
sprintf(OBuff+3*j+(j>7),"%02X ",Buff[Pos]&255);
if((Buff[Pos]&255)<32||Buff[Pos]==127)
Str[j]='.';
else
Str[j]=Buff[Pos];
} else
{
sprintf(OBuff+3*j+(j>7)," ");
Str[j]=' ';
}
}
Str[16]=0;
OBuff[3*16+1]=0;
p+=sprintf(p,"%08X: %s \"%s\"\n",i*16,OBuff,Str);
}
}
p+=sprintf(p,"\n");
return Out;
}

bool IsLogging(void)
{
return true;
//	return WaitForSingleObject(hEvent,0)==WAIT_OBJECT_0;
}

void LogData(PUCHAR Data, int NBytes)
{
if(!IsLogging())
return;
HANDLE h=CreateFile(L"\\logging.txt",GENERIC_WRITE,FILE_SHARE_READ|FILE_SHARE_WRITE,
0,OPEN_ALWAYS,0,0);
if(h==INVALID_HANDLE_VALUE)
return;
SetFilePointer(h,0,0,FILE_END);
DWORD W;
WriteFile(h,Data,NBytes,&W,0);
CloseHandle(h);
}

void LogStr(char*Str)
{
LogData((PUCHAR)Str, strlen(Str));
LogData((PUCHAR)"\n",1);
}

BOOL APIENTRY DllMain( HANDLE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}

#undef SERIAL_API
#define SERIAL_API extern "C" __declspec(dllexport)

SERIAL_API BOOL COM_Close(
DWORD pContext
)
{
LogStr("COM_Close");
return _COM_Close(pContext);
}

SERIAL_API BOOL COM_Deinit(DWORD pContext)
{
LogStr("COM_Deinit");
return _COM_Deinit(pContext);
}

SERIAL_API BOOL COM_IOControl(
DWORD dwOpenData,
DWORD dwCode,
PBYTE pBufIn,
DWORD dwLenIn,
PBYTE pBufOut,
DWORD dwLenOut,
PDWORD pdwActualOut
)
{
char Buff[1024];
sprintf(Buff,"COM_IOControl: %04X ",dwCode);
LogStr(Buff);
LogStr(Dump(pBufIn,dwLenIn));
return _COM_IOControl(
dwOpenData,
dwCode,
pBufIn,
dwLenIn,
pBufOut,
dwLenOut,
pdwActualOut);
}

SERIAL_API HANDLE COM_Init(
wchar_t* Identifier
)
{
LogStr("COM_Init");
if(hEvent==0)
{
hEvent=CreateEvent(0,TRUE,FALSE,L"seRILal logging event");

HINSTANCE H=LoadLibrary(L"Serial_BTUR.dll");
if(H==0)
{
LogStr("Error loading DLL");
return 0;
}

_COM_Deinit=(t_COM_Deinit*)GetProcAddress(H,L"COM_Deinit");
if(_COM_Deinit==0)
LogStr("COM_Deinit==0");
_COM_IOControl=(t_COM_IOControl*)GetProcAddress(H,L"COM_IOControl");
if(_COM_IOControl==0)
LogStr("COM_IOControl==0");
_COM_Init=(t_COM_Init*)GetProcAddress(H,L"COM_Init");
if(_COM_Init==0)
LogStr("COM_Init==0");
_COM_Open=(t_COM_Open*)GetProcAddress(H,L"COM_Open");
if(_COM_Open==0)
LogStr("COM_Open==0");
_COM_PowerDown=(t_COM_PowerDown*)GetProcAddress(H,L"COM_PowerDown");
if(_COM_PowerDown==0)
LogStr("COM_PowerDown==0");
_COM_PowerUp=(t_COM_PowerUp*)GetProcAddress(H,L"COM_PowerUp");
if(_COM_PowerUp==0)
LogStr("COM_PowerUp==0");
_COM_Read=(t_COM_Read*)GetProcAddress(H,L"COM_Read");
if(_COM_Read==0)
LogStr("COM_Read==0");
_COM_Write=(t_COM_Write*)GetProcAddress(H,L"COM_Write");
if(_COM_Write==0)
LogStr("COM_Write==0");
_COM_Close=(t_COM_Close*)GetProcAddress(H,L"COM_Close");
if(_COM_Close==0)
LogStr("COM_Close==0");
LogStr("DLL loaded");
}
HANDLE H=_COM_Init((DWORD)Identifier);
return H;
}

SERIAL_API HANDLE COM_Open(
HANDLE pContext,
DWORD AccessCode,
DWORD ShareMode
)
{
LogStr("COM_Open");
return _COM_Open(
pContext,
AccessCode,
ShareMode);
}

SERIAL_API BOOL COM_PowerDown(
HANDLE pContext
)
{
LogStr("COM_PowerDown");
return _COM_PowerDown(pContext);
}

SERIAL_API BOOL COM_PowerUp(
HANDLE pContext
)
{
LogStr("COM_PowerUp");
return _COM_PowerUp(pContext);
}

int SCO_Handle=0;

SERIAL_API ULONG COM_Read(
HANDLE pContext,
PUCHAR pTargetBuffer,
ULONG BufferLength
)
{
int L=_COM_Read(
pContext,
pTargetBuffer,
BufferLength);

if(L)
{
LogStr("COM_Read");
if(L>2&&pTargetBuffer[0]==4)
{
char Buff[1024];
int m=pTargetBuffer[1];
sprintf(Buff,"%s - %02X",FindEvent(m),m);
LogStr(Buff);

if(pTargetBuffer[1]==3 && pTargetBuffer[3]==0 && pTargetBuffer[12]==0)
{
LogStr("SCO connection");
SCO_Handle=pTargetBuffer[4]+pTargetBuffer[5]*256;
}

}
LogStr(Dump(pTargetBuffer,L));
}
return L;
}

SERIAL_API ULONG COM_Write(
HANDLE pContext,
PUCHAR pSourceBytes,
int NumberOfBytes
)
{
LogStr("COM_Write");
if(SCO_Handle)
{
LogStr("sending SCO packet");
char Buffer[256];
Buffer[0]=SCO_Handle&255;
Buffer[1]=SCO_Handle/255;
Buffer[2]=240;
for(int i=0; i<240; i++)
Buffer[3+i]=(i&2)?127:0;
_COM_Write(
pContext,
(unsigned char*)"\x03",
1);
_COM_Write(
pContext,
(unsigned char*)Buffer,
240+3);
SCO_Handle=0;
}
if(NumberOfBytes>2)
{
char Buff[1024];
int m=pSourceBytes[1]*256+pSourceBytes[0];
sprintf(Buff,"%s - %04X",FindMessage(m),m);
LogStr(Buff);
}
LogStr(Dump(pSourceBytes,NumberOfBytes));
return _COM_Write(
pContext,
pSourceBytes,
NumberOfBytes);
}

SERIAL_API ULONG COM_Seek()
{
return -1;
}