// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of the License "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:

 // e32\memmodel\epoc\multiple\x86\xsched.cia

 // 

 //

 #include <x86_mem.h>

 GLDEF_C __NAKED__ void DoProcessSwitch()

 	{

 	// Enter with kernel locked

 	// EBX = pointer to new thread (NThread)

 	// EDI = pointer to TScheduler

 	// ESI = pointer to TSubScheduler (SMP only)

 	// Preserve ESI, EDI

 	// eax = new process (DX86PlatProcess)

 	asm("mov eax, [ebx+%0]": : "i"_FOFF(NThreadBase,iAddressSpace)); 

 #ifdef __SMP__

 	asm("cmp eax, [esi+%0]": :"i"_FOFF(TSubScheduler,iAddressSpace));

 #else

 	asm("cmp eax, [edi+%0]": : "i"_FOFF(TScheduler,iAddressSpace));

 #endif

 	asm("jz no_as_switch");

 	asm("mov ecx, [eax+%0]": : "i"_FOFF(DMemModelProcess,iGlobalPageDir));

 	asm("mov cr3, ecx");

 #ifdef __SMP__

 	asm("mov [esi+%0], eax": :"i"_FOFF(TSubScheduler,iAddressSpace));

 #else

 	asm("mov [edi+%0], eax": : "i"_FOFF(TScheduler,iAddressSpace));

 #endif

 	asm("no_as_switch:");

 	// Get DThread* from NThread* (former contains latter so we go backwards in memory to get there)

 	asm("mov ecx, 0");

 	asm("lea ecx, [ecx+%0]": : "i"_FOFF(DThread,iNThread));

 	asm("sub ebx, ecx");

 	// check for memory being aliased...

 	asm("mov ecx, [ebx+%0]": : "i"_FOFF(DMemModelThread,iAliasLinAddr));

 	asm("cmp ecx, 0");

 	asm("jz done");

 	// restore alias...

 	asm("mov edx, [ebx+%0]": : "i"_FOFF(DMemModelThread,iAliasPdePtr));

 	asm("mov eax, [ebx+%0]": : "i"_FOFF(DMemModelThread,iAliasPde));

 	asm("mov [edx], eax");

 	asm("invlpg [ecx]");

 	asm("done:");

 	asm("ret");

 	};