--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graphicsdeviceinterface/screendriver/scdv_switch/scdvswitch.cpp	Tue Feb 02 01:47:50 2010 +0200
@@ -0,0 +1,116 @@
+// 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];
+
+
+void Stop(char* aErrorMessage)
+	{
+	int err = GetLastError();
+	RDebug::Printf("%S, (last error = %i)", aErrorMessage, err);
+	_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";
+
+	RDebug::Printf("Redirecting scdv.dll to \"%s\" ...\n", library);
+	
+	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);
+		RDebug::Printf("... DLL loaded successfully");
+		}
+	}
+
+__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
+	}
+
+}