kernel/eka/memmodel/epoc/flexible/x86/xkernel.cpp
changeset 43 96e5fb8b040d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kernel/eka/memmodel/epoc/flexible/x86/xkernel.cpp	Thu Dec 17 09:24:54 2009 +0200
@@ -0,0 +1,88 @@
+// Copyright (c) 1994-2009 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:
+//
+
+#include <x86_mem.h>
+#include "mm.h"
+
+
+TInt DX86PlatThread::SetupContext(SThreadCreateInfo& aInfo)
+	{
+	switch(iThreadType)
+		{
+		case EThreadSupervisor:
+		case EThreadMinimalSupervisor:
+		case EThreadInitial:
+		case EThreadAPInitial:
+			break;
+		case EThreadUser:
+			break;
+		}
+	iNThread.SetAddressSpace(iOwningProcess);
+	iNThread.SetAttributes(KThreadAttAddressSpace);
+#ifdef __SMP__
+	iCpuRestoreCookie = -1;
+#else
+	// OK to get this thread's owning process os asid as the process can't free
+	// it's asid while this thread is being created because the current thread
+	// has the same owning process.
+	MM::IpcAliasPde(iAliasPdePtr,((DMemModelProcess*)iOwningProcess)->OsAsid());
+#endif
+	return KErrNone;
+	}
+
+TIpcExcTrap::TExcLocation TIpcExcTrap::ExcLocation(DThread* aThread, TAny* aContext)
+	{
+	TX86ExcInfo& info=*(TX86ExcInfo*)aContext;
+	if (info.iExcId==EX86VectorPageFault)
+		{
+		TLinAddr va=(TLinAddr)info.iFaultAddress;
+
+		TLinAddr aliasAddr = ((DMemModelThread*)aThread)->iAliasLinAddr;
+		TBool remoteError;
+		if(aliasAddr)
+			remoteError = TUint(va^aliasAddr)<TUint(KPageSize);
+		else
+			// The second clause in the statement below was "va < iRemoteBase + iSize".
+			// iRemoteBase + iSize might conceivably wrap round.
+			// The usual fix for this is to change
+			//			va >= base && va < base + size
+			// to		va >= base && (va - base) < size
+			// but this requires the first clause (va >= base) so that va-base doesn't wrap negative.
+			// Since the first clause in this expression is va >= (iRemoteBase & ~3)
+			// we have to re-write the expression as follows:
+			// Let base' = iRemoteBase & ~3
+			// so  base  = base' + (base & 3)
+			// then we have va >= base' && va < base' + (base & 3) + iSize
+			// (effectively the & ~3 on the first clause extends the range downwards by base & 3)
+			remoteError = va>=(iRemoteBase&~3) &&
+				(va - (iRemoteBase & ~3)) < iSize + (iRemoteBase & 3);
+		if (remoteError)
+			return EExcRemote;
+
+		// Third clause was va < iLocalBase + iSize, fixed as in the "remoteError =" line above
+		if (iLocalBase && va>=(iLocalBase&~3) &&
+			(va - (iLocalBase & ~3)) < iSize + (iLocalBase & 3))
+			return EExcLocal;
+		}
+	else if (info.iExcId==EX86VectorGPF)
+		{
+		TUint16 ds=(TUint16)info.iDs;
+		TUint16 es=(TUint16)info.iEs;
+		TUint16 seg=iDir?ds:es;	// write -> local read -> DS restricted, else ES restricted
+		if (seg==KRing3DS || seg==KRing3CS)
+			return EExcLocal;
+		}
+	return EExcUnknown;
+	}