// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 // For the Winscw Emulator only, selects between GCE and non-GCE version of Screen Driver.

 // The default is the non-GCE based version.

 // To select the GCE version do one of:

 // 1. Add a line to the epoc.ini file in \epoc32\data like this:

 // symbian_graphics_use_gce ON

 // or

 // 2. Start epoc.exe with these parameters, (the "--" IS necessary):

 // -Dsymbian_graphics_use_gce=ON --

 // or

 // 3. epoc.exe can be told to switch to a different initialisation file than epoc.ini, with the -M parameter.

 // Progress chaining to the real Scdv is logged in epocwind.out.

 // 

 //

 #include <emulator.h>

 #include <e32svr.h>

 #include <u32hal.h>

 extern "C" {

 #include "scdv_stubs.h"

 FARPROC vector[MAX_ORDINAL+1];

 #ifdef _DEBUG

 void Stop(char* aErrorMessage)

 #else

 void Stop(char* /*aErrorMessage*/)

 #endif

 	{

 	int err = GetLastError();

 #ifdef _DEBUG

 	RDebug::Printf("%S, (last error = %i)", aErrorMessage, err);

 #endif

 	_asm int 3;

 	}

 void fill_vector(HINSTANCE aDll)

 	{

 	int i;

 	FARPROC address = NULL;

 	for (i=1;i<=MAX_ORDINAL;i++)

 		{

 		address = GetProcAddress(aDll, (LPCSTR)i);

 		if (address == NULL)

 			{

 			Stop("... has too few exported functions");

 			}

 		vector[i] = address;

 		}

 	address = GetProcAddress(aDll, (LPCSTR)i);

 	if (address != NULL)

 		{

 		Stop("... has too many exported functions");

 		}

 	vector[0] = (FARPROC)1;		// initialised

 	}

 // redirects DLL calls to GCE or non-GCE implementation

 void init_vector()

 	{

 	// ask HAL which configuration to use

 	TBool gce = EFalse;

 	UserSvr::HalFunction(EHalGroupEmulator, EEmulatorHalBoolProperty,  (TAny*)"symbian_graphics_use_gce",  &gce);

 	const char* library = gce ? "_generic_scdv.dll" : "_wins_scdv.dll";

 #ifdef _DEBUG

 	RDebug::Printf("Redirecting scdv.dll to \"%s\" ...\n", library);

 #endif

 	Emulator::Escape();		// prevent deadlock between EKA2 scheduler and MS kernel

 	// try to load selected DLL

 	HINSTANCE instance = LoadLibraryA(library);

 	Emulator::Reenter();

 	if (instance == NULL)

 		{

 		Stop("... unable to load");

 		}

 	else

 		{

 		fill_vector(instance);

 #ifdef _DEBUG

 		RDebug::Printf("... DLL loaded successfully");

 #endif

 		}

 	}

 __declspec(naked) void common_dispatch()

 	{

 	_asm cmp	dword ptr vector,0		// initialised?

 	_asm je  	do_init_vector

 call_though_vector:

 	_asm jmp	[vector+eax*4]

 do_init_vector:

 	_asm push	eax

 	_asm push	ecx

 	_asm push	edx

 	_asm call	init_vector

 	_asm pop	edx

 	_asm pop 	ecx

 	_asm pop 	eax

 	_asm jmp	call_though_vector

 	}

 }