--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kernel/eka/memmodel/epoc/direct/arm/xutils.cpp	Thu Dec 17 09:24:54 2009 +0200
@@ -0,0 +1,82 @@
+// 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:
+// e32\memmodel\epoc\direct\arm\xutils.cpp
+// 
+//
+
+//#define __DBG_MON_FAULT__
+//#define __RAM_LOADED_CODE__
+//#define __EARLY_DEBUG__
+
+#include "arm_mem.h"
+
+/**
+	@pre	Call in a thread context.
+	@pre	Interrupts must be enabled.
+	@pre	Kernel must be unlocked.
+ */
+EXPORT_C TPhysAddr Epoc::LinearToPhysical(TLinAddr aLinAddr)
+	{
+	CHECK_PRECONDITIONS(MASK_KERNEL_UNLOCKED|MASK_INTERRUPTS_ENABLED|MASK_NOT_ISR|MASK_NOT_IDFC,"Epoc::LinearToPhysical");
+	__KTRACE_OPT(KMMU,Kern::Printf("Epoc::LinearToPhysical(%08x)", aLinAddr));
+#ifdef __CPU_HAS_MMU
+	// Deal with faking no MMU on hardware with an MMU
+	if (!Arm::MmuActive())
+		return aLinAddr;
+	TUint32 phys=0xffffffffu;
+	TUint32 pdphys = Arm::MmuTTBR0();
+	TUint32 pdlin = TheSuperPage().iPageDir;
+	TUint32 offset = pdlin - pdphys;	// offset from phys to lin for page directory/tables
+	const TUint32* pageDir = (const TUint32*)pdlin;
+	TUint32 pde = pageDir[aLinAddr>>20];
+	__KTRACE_OPT(KMMU,Kern::Printf("PDE %08x", pde));
+	if ((pde&3)==2)
+		{
+		// section
+		phys = (pde&0xfff00000u) | (aLinAddr&0x000fffffu);
+		}
+	else if ((pde&3)==1)
+		{
+		// page table
+		TUint32 ptphys = pde & 0xfffffc00u;
+		const TUint32* pageTable = (const TUint32*)(ptphys + offset);
+		TUint32 pte = pageTable[(aLinAddr>>12)&0xff];
+		__KTRACE_OPT(KMMU,Kern::Printf("PTE %08x", pte));
+		if ((pte&3)==1)
+			{
+			// 64K page
+			phys = (pte&0xffff0000u) | (aLinAddr&0x0000ffffu);
+			}
+		else if (pte&3)
+			{
+			// 4K page
+			phys = (pte&0xfffff000u) | (aLinAddr&0x00000fffu);
+			}
+		else
+			{
+			FAULT();
+			}
+		}
+	else
+		{
+		FAULT();
+		}
+	__KTRACE_OPT(KMMU,Kern::Printf("Physical address = %08x",phys));
+	return phys;
+#else
+	// real non-MMU hardware
+	return aLinAddr;
+#endif
+	}
+