--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/kernel/eka/memmodel/epoc/flexible/mmu/mmu.cpp	Thu Dec 17 09:24:54 2009 +0200
@@ -0,0 +1,2434 @@
+// Copyright (c) 1998-2009 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 "memmodel.h"
+#include "kernel/cache_maintenance.inl"
+#include <kernel/cache.h>
+#include <ramalloc.h>
+#include <defrag.h>
+#include "mm.h"
+#include "mmu.h"
+#include "mpager.h"
+#include "mmapping.h"
+#include "mobject.h"
+#include "mmanager.h"
+#include "mpagearray.h"
+
+
+//
+// SPageInfo
+//
+
+// check enough space for page infos...
+__ASSERT_COMPILE((KPageInfoLinearEnd-KPageInfoLinearBase)/sizeof(SPageInfo)==(1<<(32-KPageShift)));
+
+// check KPageInfoShift...
+__ASSERT_COMPILE(sizeof(SPageInfo)==(1<<KPageInfoShift));
+
+
+SPageInfo* SPageInfo::SafeFromPhysAddr(TPhysAddr aAddress)
+	{
+	__NK_ASSERT_DEBUG((aAddress&KPageMask)==0);
+	TUint index = aAddress>>(KPageShift+KPageShift-KPageInfoShift);
+	TUint flags = ((TUint8*)KPageInfoMap)[index>>3];
+	TUint mask = 1<<(index&7);
+	if(!(flags&mask))
+		return 0; // no SPageInfo for aAddress
+	SPageInfo* info = FromPhysAddr(aAddress);
+	if(info->iType==SPageInfo::EInvalid)
+		return 0;
+	return info;
+	}
+
+
+#ifdef _DEBUG
+
+void SPageInfo::CheckAccess(const char* aMessage, TUint aFlags)
+	{
+	if(K::Initialising || NKern::Crashed())
+		return;
+
+	if((aFlags&ECheckNotAllocated) && (iType!=EUnknown))
+		{
+		Kern::Printf("SPageInfo[0x%08x]::CheckAccess failed, PhysAddr()=0x%08x, iType==%d : %s",this,PhysAddr(),iType,aMessage);
+		__NK_ASSERT_DEBUG(0);
+		goto fail;
+		}
+
+	if((aFlags&ECheckNotUnused) && (iType==EUnused))
+		{
+		Kern::Printf("SPageInfo[0x%08x]::CheckAccess failed, PhysAddr()=0x%08x, iType==%d : %s",this,PhysAddr(),iType,aMessage);
+		__NK_ASSERT_DEBUG(0);
+		goto fail;
+		}
+
+	if((aFlags&ECheckUnused) && (iType!=EUnused))
+		{
+		Kern::Printf("SPageInfo[0x%08x]::CheckAccess failed, PhysAddr()=0x%08x, iType==%d : %s",this,PhysAddr(),iType,aMessage);
+		__NK_ASSERT_DEBUG(0);
+		goto fail;
+		}
+
+	if((aFlags&ECheckNotPaged) && (iPagedState!=EUnpaged))
+		{
+		Kern::Printf("SPageInfo[0x%08x]::CheckAccess failed, PhysAddr()=0x%08x, iPagedState=%d : %s",this,PhysAddr(),iPagedState,aMessage);
+		__NK_ASSERT_DEBUG(0);
+		goto fail;
+		}
+
+	if((aFlags&ECheckRamAllocLock) && !RamAllocLock::IsHeld())
+		{
+		Kern::Printf("SPageInfo[0x%08x]::CheckAccess failed, PhysAddr()=0x%08x, iType==%d : %s",this,PhysAddr(),iType,aMessage);
+		__NK_ASSERT_DEBUG(0);
+		goto fail;
+		}
+
+	if((aFlags&ENoCheckMmuLock) || MmuLock::IsHeld())
+		return;
+fail:
+	Kern::Printf("SPageInfo[0x%08x]::CheckAccess failed, PhysAddr()=0x%08x : %s",this,PhysAddr(),aMessage);
+	Mmu::Panic(Mmu::EUnsafePageInfoAccess);
+	}
+
+
+void SPageInfo::Dump()
+	{
+	Kern::Printf("SPageInfo for page %x = %d,%d,%02x,0x%08x,0x%x,%d",PhysAddr(),iType,iPagedState,iFlags,iOwner,iIndex,iPinCount);
+	}
+
+#endif
+
+
+
+//
+// SPageTableInfo
+//
+
+// check enough space for page table infos...
+__ASSERT_COMPILE((KPageTableInfoEnd-KPageTableInfoBase)/sizeof(SPageTableInfo)
+					>=(KPageTableEnd-KPageTableBase)/KPageTableSize);
+
+// check KPtBlockShift...
+__ASSERT_COMPILE((sizeof(SPageTableInfo)<<KPtBlockShift)==KPageSize);
+
+
+#ifdef _DEBUG
+
+TBool SPageTableInfo::CheckPageCount()
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld());
+	TPte* pt = PageTable();
+	TUint realCount = 0;
+	do if(*pt++) ++realCount;
+	while(TLinAddr(pt)&(KPageTableMask/sizeof(TPte)*sizeof(TPte)));
+	if(iPageCount==realCount)
+		return true;
+	Kern::Printf("CheckPageCount Failed: pt=0x%08x count=%d realCount=%d",TLinAddr(pt)-KPageTableSize,iPageCount,realCount);
+	return false;
+	}
+
+
+void SPageTableInfo::CheckChangeUse(const char* aName)
+	{
+	if(K::Initialising)
+		return;
+	if(PageTablesLockIsHeld() && MmuLock::IsHeld())
+		return;
+	Kern::Printf("SPageTableInfo::CheckChangeUse failed : %s",aName);
+	Mmu::Panic(Mmu::EUnsafePageTableInfoAccess);
+	}
+
+
+void SPageTableInfo::CheckCheckUse(const char* aName)
+	{
+	if(K::Initialising)
+		return;
+	if(PageTablesLockIsHeld() || MmuLock::IsHeld())
+		return;
+	Kern::Printf("SPageTableInfo::CheckCheckUse failed : %s",aName);
+	Mmu::Panic(Mmu::EUnsafePageTableInfoAccess);
+	}
+
+
+void SPageTableInfo::CheckAccess(const char* aName)
+	{
+	if(K::Initialising)
+		return;
+	if(MmuLock::IsHeld())
+		return;
+	Kern::Printf("SPageTableInfo::CheckAccess failed : %s",aName);
+	Mmu::Panic(Mmu::EUnsafePageTableInfoAccess);
+	}
+
+
+void SPageTableInfo::CheckInit(const char* aName)
+	{
+	if(K::Initialising)
+		return;
+	if(PageTablesLockIsHeld() && iType==EUnused)
+		return;
+	Kern::Printf("SPageTableInfo::CheckInit failed : %s",aName);
+	Mmu::Panic(Mmu::EUnsafePageTableInfoAccess);
+	}
+
+#endif
+
+
+
+//
+// RamAllocLock
+//
+
+_LIT(KLitRamAlloc,"RamAlloc");
+_LIT(KLitPhysMemSync,"PhysMemSync");
+
+void RamAllocLock::Lock()
+	{
+	Mmu& m = TheMmu;
+	Kern::MutexWait(*m.iRamAllocatorMutex);
+	if(!m.iRamAllocLockCount++)
+		{
+		// first lock, so setup memory fail data...
+		m.iRamAllocFailed = EFalse;
+		__NK_ASSERT_DEBUG(m.iRamAllocInitialFreePages==m.FreeRamInPages()); // free RAM shouldn't have changed whilst lock was held
+		}
+	}
+
+
+void RamAllocLock::Unlock()
+	{
+	Mmu& m = TheMmu;
+	if(--m.iRamAllocLockCount)
+		{
+		Kern::MutexSignal(*m.iRamAllocatorMutex);
+		return;
+		}
+	TBool failed = m.iRamAllocFailed;
+	TUint initial = m.iRamAllocInitialFreePages;
+	TUint final = m.FreeRamInPages();
+	m.iRamAllocInitialFreePages = final; // new baseline value
+	TUint changes = K::CheckFreeMemoryLevel(initial*KPageSize,final*KPageSize,failed);
+	if(changes)
+		{
+		__KTRACE_OPT(KMMU,Kern::Printf("RamAllocLock::Unlock() changes=%x",changes));
+		}
+	Kern::MutexSignal(*m.iRamAllocatorMutex);
+	}
+
+
+TBool RamAllocLock::Flash()
+	{
+	Unlock();
+	Lock();
+	return true; // lock was released
+	}
+
+
+TBool RamAllocLock::IsHeld()
+	{
+	Mmu& m = TheMmu;
+	return m.iRamAllocatorMutex->iCleanup.iThread == &Kern::CurrentThread() && m.iRamAllocLockCount;
+	}
+
+
+
+//
+// MmuLock
+//
+
+#ifdef _DEBUG
+TUint MmuLock::UnlockGuardNest =0;
+TUint MmuLock::UnlockGuardFail =0;
+#endif
+
+NFastMutex MmuLock::iLock;
+
+void MmuLock::Lock()
+	{
+	NKern::FMWait(&iLock);
+	}
+
+void MmuLock::Unlock()
+	{
+	UnlockGuardCheck();
+	NKern::FMSignal(&iLock);
+	}
+
+TBool MmuLock::Flash()
+	{
+	UnlockGuardCheck();
+	return NKern::FMFlash(&iLock);
+	}
+
+TBool MmuLock::IsHeld()
+	{
+	NFastMutex& m = iLock;
+	return m.HeldByCurrentThread();
+	}
+
+
+
+//
+// Initialisation
+//
+
+Mmu TheMmu;
+
+void Mmu::Init1Common()
+	{
+	__KTRACE_OPT2(KBOOT,KMMU,Kern::Printf("Mmu::Init1Common"));
+
+	// Mmu data
+	TUint pteType = PteType(ESupervisorReadWrite,true);
+	iTempPteCached = BlankPte((TMemoryAttributes)(EMemoryAttributeNormalCached|EMemoryAttributeDefaultShareable),pteType);
+	iTempPteUncached = BlankPte((TMemoryAttributes)(EMemoryAttributeNormalUncached|EMemoryAttributeDefaultShareable),pteType);
+	iTempPteCacheMaintenance = BlankPte((TMemoryAttributes)(CacheMaintenance::TemporaryMapping()|EMemoryAttributeDefaultShareable),pteType);
+	
+	// other
+	PP::MaxUserThreadStack=0x14000;			// 80K - STDLIB asks for 64K for PosixServer!!!!
+	PP::UserThreadStackGuard=0x2000;		// 8K
+	PP::MaxStackSpacePerProcess=0x200000;	// 2Mb
+	K::SupervisorThreadStackSize=0x1000;	// 4K
+	PP::SupervisorThreadStackGuard=0x1000;	// 4K
+	K::MachineConfig=(TMachineConfig*)KMachineConfigLinAddr;
+	PP::RamDriveStartAddress=0;
+	PP::RamDriveRange=0;
+	PP::RamDriveMaxSize=0x20000000;	// 512MB, probably will be reduced later
+	K::MemModelAttributes=EMemModelTypeFlexible|EMemModelAttrNonExProt|EMemModelAttrKernProt|EMemModelAttrWriteProt|
+						EMemModelAttrVA|EMemModelAttrProcessProt|EMemModelAttrSameVA|EMemModelAttrSvKernProt|
+						EMemModelAttrIPCKernProt|EMemModelAttrRamCodeProt;
+	}
+
+
+#if 0
+void Mmu::VerifyRam()
+	{
+	Kern::Printf("Mmu::VerifyRam() pass 1");
+	RamAllocLock::Lock();
+
+	TPhysAddr p = 0;
+	do
+		{
+		SPageInfo* pi = SPageInfo::SafeFromPhysAddr(p);
+		if(pi)
+			{
+			Kern::Printf("%08x %d",p,pi->Type());
+			if(pi->Type()==SPageInfo::EUnused)
+				{
+				volatile TPhysAddr* b = (volatile TPhysAddr*)MapTemp(p,0);
+				b[0] = p;
+				b[1] = ~p;
+				__NK_ASSERT_DEBUG(b[0]==p);
+				__NK_ASSERT_DEBUG(b[1]==~p);
+				UnmapTemp();
+				}
+			}
+		p += KPageSize;
+		}
+	while(p);
+
+	TBool fail = false;
+	Kern::Printf("Mmu::VerifyRam() pass 2");
+	do
+		{
+		SPageInfo* pi = SPageInfo::SafeFromPhysAddr(p);
+		if(pi)
+			{
+			if(pi->Type()==SPageInfo::EUnused)
+				{
+				volatile TPhysAddr* b = (volatile TPhysAddr*)MapTemp(p,0);
+				if(b[0]!=p || b[1]!=~p)
+					{
+					fail = true;
+					Kern::Printf("%08x FAILED %x %x",b[0],b[1]);
+					}
+				UnmapTemp();
+				}
+			}
+		p += KPageSize;
+		}
+	while(p);
+
+	__NK_ASSERT_DEBUG(!fail);
+	RamAllocLock::Unlock();
+	}
+#endif
+
+
+void Mmu::Init2Common()
+	{
+	__KTRACE_OPT2(KBOOT,KMMU,Kern::Printf("Mmu::Init2Common"));
+
+	// create allocator...
+	const SRamInfo& info = *(const SRamInfo*)TheSuperPage().iRamBootData;
+	iRamPageAllocator = DRamAllocator::New(info, iRamZones, iRamZoneCallback);
+
+	// initialise all pages in banks as unused...
+	const SRamBank* bank = info.iBanks;
+	while(bank->iSize)
+		{
+		TUint32 base = bank->iBase;
+		TUint32 size = bank->iSize;
+		__KTRACE_OPT2(KBOOT,KMMU,Kern::Printf("Found RAM bank 0x%08x size %d",base,size));
+		if(base+size<=base || ((base|size)&KPageMask))
+			Panic(EInvalidRamBankAtBoot);
+
+		SPageInfo* pi = SPageInfo::FromPhysAddr(base);
+		SPageInfo* piEnd = pi+(size>>KPageShift);
+		while(pi<piEnd)
+			(pi++)->SetUnused();
+		++bank;
+		}
+	// step over the last bank to get to the reserved banks.
+	++bank;
+	// mark any reserved regions as allocated...
+	while(bank->iSize)
+		{
+		TUint32 base = bank->iBase;
+		TUint32 size = bank->iSize;
+		__KTRACE_OPT2(KBOOT,KMMU,Kern::Printf("Found reserved bank 0x%08x size %d",base,size));
+		if(base+size<=base || ((base|size)&KPageMask))
+			Panic(EInvalidReservedBankAtBoot);
+
+		SPageInfo* pi = SPageInfo::FromPhysAddr(base);
+		SPageInfo* piEnd = pi+(size>>KPageShift);
+		while(pi<piEnd)
+			(pi++)->SetPhysAlloc();
+		++bank;
+		}
+
+	// Clear the inital (and only so far) page table info page so all unused
+	// page tables infos will be marked as unused.
+	__ASSERT_COMPILE(SPageTableInfo::EUnused == 0);
+	memclr((TAny*)KPageTableInfoBase, KPageSize);
+
+	// look for page tables - assume first page table maps page tables
+	TPte* pPte = (TPte*)KPageTableBase;
+	TInt i;
+	for(i=0; i<KChunkSize/KPageSize; ++i)
+		{
+		TPte pte = *pPte++;
+		if(pte==KPteUnallocatedEntry)	// after boot, page tables are contiguous
+			break;
+		TPhysAddr ptpgPhys = Mmu::PtePhysAddr(pte,i);
+		__KTRACE_OPT(KBOOT,Kern::Printf("Page Table Group %08x -> Phys %08x", KPageTableBase+i*KPageSize, ptpgPhys));
+		SPageInfo* pi = SPageInfo::SafeFromPhysAddr(ptpgPhys);
+		__ASSERT_ALWAYS(pi, Panic(EInvalidPageTableAtBoot));
+		pi->SetFixed(i); // this also sets the SPageInfo::iOffset so that linear-to-physical works
+		}
+
+	// look for mapped pages
+	TPde* pd = Mmu::PageDirectory(KKernelOsAsid);
+	for(i=0; i<(1<<(32-KChunkShift)); ++i)
+		{
+		TPde pde = pd[i];
+		if(pde==KPdeUnallocatedEntry)
+			continue;
+		TPhysAddr pdePhys = Mmu::PdePhysAddr(pde);
+		TPte* pt = 0;
+		if(pdePhys!=KPhysAddrInvalid)
+			{
+			__KTRACE_OPT(KBOOT,Kern::Printf("Addr %08x -> Whole PDE Phys %08x", i<<KChunkShift, pdePhys));
+			}
+		else
+			{
+			pt = Mmu::PageTableFromPde(pde);
+			__KTRACE_OPT(KBOOT,Kern::Printf("Addr %08x -> page table %08x", i<<KChunkShift, pt));
+			__ASSERT_ALWAYS(pt,Panic(EInvalidPdeAtBoot)); // bad PDE
+			}
+
+		TInt j;
+		TInt np = 0;
+		for(j=0; j<KChunkSize/KPageSize; ++j)
+			{
+			TBool present = ETrue;	// all pages present if whole PDE mapping
+			TPte pte = 0;
+			if(pt)
+				{
+				pte = pt[j];
+				present = pte!=KPteUnallocatedEntry;
+				}
+			if(present)
+				{
+				++np;
+				TPhysAddr pa = pt ? Mmu::PtePhysAddr(pte,j) : (pdePhys + (j<<KPageShift));
+				SPageInfo* pi = SPageInfo::SafeFromPhysAddr(pa);
+				__KTRACE_OPT(KBOOT,Kern::Printf("Addr: %08x PA=%08x",
+													(i<<KChunkShift)+(j<<KPageShift), pa));
+				if(pi)	// ignore non-RAM mappings
+					{
+					TInt r = iRamPageAllocator->MarkPageAllocated(pa, EPageFixed);
+					// allow KErrAlreadyExists since it's possible that a page is doubly mapped
+					__ASSERT_ALWAYS(r==KErrNone || r==KErrAlreadyExists, Panic(EBadMappedPageAfterBoot));
+					if(pi->Type()==SPageInfo::EUnused)
+						pi->SetFixed();
+					}
+				}
+			}
+		__KTRACE_OPT(KBOOT,Kern::Printf("Addr: %08x #PTEs=%d",(i<<KChunkShift),np));
+		if(pt)
+			{
+			SPageTableInfo* pti = SPageTableInfo::FromPtPtr(pt);
+			pti->Boot(np);
+			}
+		}
+
+	TInt r = K::MutexCreate(iRamAllocatorMutex, KLitRamAlloc, NULL, EFalse, KMutexOrdRamAlloc);
+	if(r!=KErrNone)
+		Panic(ERamAllocMutexCreateFailed);
+	iRamAllocLockCount = 0;
+	iRamAllocInitialFreePages = FreeRamInPages();
+
+	__KTRACE_OPT2(KBOOT,KMMU,Kern::Printf("Mmu::DoInit2"));
+
+	for(i=0; i<KNumTempMappingSlots; ++i)
+		iTempMap[i].Alloc(1);
+
+	iPhysMemSyncTemp.Alloc(1);
+	r = K::MutexCreate(iPhysMemSyncMutex, KLitPhysMemSync, NULL, EFalse, KMutexOrdSyncPhysMem);
+	if(r!=KErrNone)
+		Panic(EPhysMemSyncMutexCreateFailed);
+//	VerifyRam();
+	}
+
+
+void Mmu::Init2FinalCommon()
+	{
+	__KTRACE_OPT2(KBOOT,KMMU,Kern::Printf("Mmu::Init2FinalCommon"));
+	// hack, reduce free memory to <2GB...
+	while(FreeRamInPages()>=0x80000000/KPageSize)
+		{
+		TPhysAddr dummyPage;
+		TInt r = iRamPageAllocator->AllocRamPages(&dummyPage,1, EPageFixed);
+		__NK_ASSERT_ALWAYS(r==KErrNone);
+		}
+	// hack, reduce total RAM to <2GB...
+	if(TheSuperPage().iTotalRamSize<0)
+		TheSuperPage().iTotalRamSize = 0x80000000-KPageSize;
+
+	// Save current free RAM size - there can never be more free RAM than this
+	TUint maxFreePages = FreeRamInPages();
+	K::MaxFreeRam = maxFreePages*KPageSize;
+	if(maxFreePages < (TUint(PP::RamDriveMaxSize)>>KPageShift))
+		PP::RamDriveMaxSize = maxFreePages*KPageSize;
+
+	// update this to stop assert triggering in RamAllocLock::Lock()
+	iRamAllocInitialFreePages = maxFreePages;
+	}
+
+ 
+void Mmu::Init3()
+	{
+	iDefrag = new Defrag;
+	if (!iDefrag)
+		Panic(EDefragAllocFailed);
+	iDefrag->Init3(TheMmu.iRamPageAllocator);
+	}
+
+//
+// Utils
+//
+
+void Mmu::Panic(TPanic aPanic)
+	{
+	Kern::Fault("MMU",aPanic);
+	}
+
+
+TUint Mmu::FreeRamInPages()
+	{
+	return iRamPageAllocator->FreeRamInPages()+ThePager.NumberOfFreePages();
+	}
+
+
+TUint Mmu::TotalPhysicalRamPages()
+	{
+	return iRamPageAllocator->TotalPhysicalRamPages();
+	}
+
+
+const SRamZone* Mmu::RamZoneConfig(TRamZoneCallback& aCallback) const
+	{
+	aCallback = iRamZoneCallback;
+	return iRamZones;
+	}
+
+
+void Mmu::SetRamZoneConfig(const SRamZone* aZones, TRamZoneCallback aCallback)
+	{
+	iRamZones = aZones;
+	iRamZoneCallback = aCallback;
+	}
+
+
+TInt Mmu::ModifyRamZoneFlags(TUint aId, TUint aClearMask, TUint aSetMask)
+	{
+	return iRamPageAllocator->ModifyZoneFlags(aId, aClearMask, aSetMask);
+	}
+
+
+TInt Mmu::GetRamZonePageCount(TUint aId, SRamZonePageCount& aPageData)
+	{
+	return iRamPageAllocator->GetZonePageCount(aId, aPageData);
+	}
+
+
+TInt Mmu::ZoneAllocPhysicalRam(TUint* aZoneIdList, TUint aZoneIdCount, TInt aBytes, TPhysAddr& aPhysAddr, TInt aAlign)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::ZoneAllocPhysicalRam(?,%d,%d,?,%d)", aZoneIdCount, aBytes, aPhysAddr, aAlign));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+
+	TInt r = iRamPageAllocator->ZoneAllocContiguousRam(aZoneIdList, aZoneIdCount, aBytes, aPhysAddr, EPageFixed, aAlign);
+	if(r!=KErrNone)
+		iRamAllocFailed = ETrue;
+	else
+		{
+		TUint pages = MM::RoundToPageCount(aBytes);
+		AllocatedPhysicalRam(aPhysAddr, pages,  (Mmu::TRamAllocFlags)EMemAttStronglyOrdered);
+		}
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::ZoneAllocPhysicalRam returns %d and aPhysAddr=0x%08x",r,aPhysAddr));
+	return r;
+	}
+
+
+TInt Mmu::ZoneAllocPhysicalRam(TUint* aZoneIdList, TUint aZoneIdCount, TInt aNumPages, TPhysAddr* aPageList)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::ZoneAllocPhysicalRam(?,%d,%d,?)", aZoneIdCount, aNumPages));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+
+	TInt r = iRamPageAllocator->ZoneAllocRamPages(aZoneIdList, aZoneIdCount, aPageList, aNumPages, EPageFixed);
+	if(r!=KErrNone)
+		iRamAllocFailed = ETrue;
+	else
+		{
+		PagesAllocated(aPageList, aNumPages, (Mmu::TRamAllocFlags)EMemAttStronglyOrdered);
+
+		// update page infos...
+		TUint flash = 0;
+		TPhysAddr* pageEnd = aPageList + aNumPages;
+		MmuLock::Lock();
+		TPhysAddr* page = aPageList;
+		while (page < pageEnd)
+			{
+			MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo/2);
+			TPhysAddr pagePhys = *page++;
+			__NK_ASSERT_DEBUG(pagePhys != KPhysAddrInvalid);
+			SPageInfo::FromPhysAddr(pagePhys)->SetPhysAlloc();
+			}
+		MmuLock::Unlock();
+		}
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::ZoneAllocPhysicalRam returns %d",r));
+	return r;
+	}
+
+
+TInt Mmu::RamHalFunction(TInt aFunction, TAny* a1, TAny* a2)
+	{
+	// This function should only be registered with hal and therefore can only 
+	// be invoked after the ram allocator has been created.
+	__NK_ASSERT_DEBUG(iRamPageAllocator);
+	return iRamPageAllocator->HalFunction(aFunction, a1, a2);
+	}
+
+
+void Mmu::ChangePageType(SPageInfo* aPageInfo, TZonePageType aOldPageType, TZonePageType aNewPageType)
+	{
+	iRamPageAllocator->ChangePageType(aPageInfo, aOldPageType, aNewPageType);
+	}
+
+TInt Mmu::HandlePageFault(TLinAddr aPc, TLinAddr aFaultAddress, TUint aAccessPermissions, TAny* aExceptionInfo)
+	{
+	TRACE(("Mmu::HandlePageFault(0x%08x,0x%08x,%d)",aPc,aFaultAddress,aAccessPermissions));
+
+	DMemModelThread* thread = (DMemModelThread*)TheCurrentThread;
+	// Get the os asid of the process taking the fault, no need to open a reference 
+	// as it is the current thread's process so can't be freed.
+	TUint faultOsAsid = ((DMemModelProcess*)thread->iNThread.iAddressSpace)->OsAsid();
+
+	// check if any fast mutexes held...
+	NFastMutex* fm = NKern::HeldFastMutex();
+	TPagingExcTrap* trap = thread->iPagingExcTrap;
+	if(fm)
+		{
+		// check there is an XTRAP_PAGING in effect...
+		if(!trap)
+			{
+			// oops, kill system...
+			__KTRACE_OPT2(KPAGING,KPANIC,Kern::Printf("Fault with FM Held! addr=0x%08x (%O pc=%x)",aFaultAddress,thread,aPc));
+			Exc::Fault(aExceptionInfo);
+			}
+
+		// release the fast mutex...
+		NKern::FMSignal(fm);
+		}
+
+	NKern::ThreadEnterCS();
+
+	// work out address space for aFaultAddress...
+	TUint osAsid = faultOsAsid;
+	TLinAddr addr = aFaultAddress;
+	if(thread->iAliasLinAddr && TUint(addr - thread->iAliasLinAddr) < TUint(KPageSize))
+		{
+		// Address in aliased memory...
+		addr = (addr - thread->iAliasLinAddr) + thread->iAliasTarget;
+		// Get the os asid of the process thread is aliasing, no need to open 
+		// a reference on it as one was already opened when the alias was created.
+		osAsid = thread->iAliasProcess->OsAsid();
+		}
+	else if(addr>=KGlobalMemoryBase)
+		{
+		// Address in global region, so look it up in kernel's address space...
+		osAsid = KKernelOsAsid;
+		}
+
+	// NOTE, osAsid will remain valid for duration of this function because it is either
+	// - The current thread's address space, which can't go away whilst the thread
+	//   is running.
+	// - The address space of another thread which we are aliasing memory from,
+	//   and we would only do this if we have a reference on this other thread,
+	//   which has a reference on it's process, which should own the address space!
+
+#ifdef __BROADCAST_CACHE_MAINTENANCE__
+	if (thread->iAliasLinAddr)
+		{
+		// If an alias is in effect, the the thread will be locked to the current CPU,
+		// but we need to be able to migrate between CPUs for cache maintainance.  This
+		// must be dealt with by removing the alias and restoring it with a paging trap
+		// handler.
+		if(!trap)
+			{
+			// oops, kill system...
+			__KTRACE_OPT2(KPAGING,KPANIC,Kern::Printf("Fault with thread locked to current CPU! addr=0x%08x (%O pc=%x)",aFaultAddress,thread,aPc));
+			Exc::Fault(aExceptionInfo);
+			}
+		thread->RemoveAlias();
+		}
+#endif
+
+	// find mapping...
+	TUint offsetInMapping;
+	TUint mapInstanceCount;
+	DMemoryMapping* mapping = MM::FindMappingInAddressSpace(osAsid, addr, 1, offsetInMapping, mapInstanceCount);
+//	TRACE(("%O mapping=0x%08x",TheCurrentThread,mapping));
+	TInt r = KErrNotFound;
+
+	if(mapping)
+		{
+		// Pinning mappings should not be found from within an address space.
+		__NK_ASSERT_DEBUG(!mapping->IsPinned());
+		MmuLock::Lock();
+
+		// check if we need to process page fault...
+		if(!Mmu::CheckPteTypePermissions(mapping->PteType(),aAccessPermissions) ||
+			mapInstanceCount != mapping->MapInstanceCount())
+			{
+			// Invalid access to the page.
+			MmuLock::Unlock();
+			r = KErrAbort;
+			}
+		else
+			{
+			// we do need to handle fault so is this a demand paging or page moving fault
+			DMemoryObject* memory = mapping->Memory();
+			if(!memory)
+				MmuLock::Unlock();
+			else
+				{
+				TUint faultIndex = (offsetInMapping >> KPageShift) + mapping->iStartIndex;
+				memory->Open();
+
+				// This is safe as we have the instance count so can detect the mapping 
+				// being reused and we have a reference to the memory object so it can't 
+				// be deleted.
+				MmuLock::Unlock();
+
+				if(memory->IsDemandPaged())
+					{
+					// Let the pager handle the fault...
+					r = ThePager.HandlePageFault(	aPc, aFaultAddress, faultOsAsid, faultIndex,
+													aAccessPermissions, memory, mapping, mapInstanceCount,
+													thread, aExceptionInfo);
+					}
+				else
+					{// The page could be being moved so verify that with its manager.
+					DMemoryManager* manager = memory->iManager;
+					r = manager->HandleFault(memory, faultIndex, mapping, mapInstanceCount, aAccessPermissions);
+					}
+				if (r == KErrNone)
+					{// alias PDE needs updating because page tables have changed...
+					thread->RefreshAlias();
+					}
+				memory->Close();
+				}
+			}
+		mapping->Close();
+		}
+
+	if (trap)
+		{
+		// restore address space (because the trap will bypass any code
+		// which would have done this.)...
+		DMemModelThread::RestoreAddressSpace();
+		}
+
+	NKern::ThreadLeaveCS();  // thread will die now if CheckRealtimeThreadFault caused a panic
+
+	// deal with XTRAP_PAGING...
+	if(trap)
+		{
+		// re-acquire any fast mutex which was held before the page fault...
+		if(fm)
+			NKern::FMWait(fm);
+		if (r == KErrNone)
+			{
+			trap->Exception(1); // return from exception trap with result '1' (value>0)
+			// code doesn't continue beyond this point.
+			__NK_ASSERT_DEBUG(0);
+			}
+		}
+
+	return r;
+	}
+
+
+//
+// Memory allocation
+//
+
+TInt Mmu::AllocRam(	TPhysAddr* aPages, TUint aCount, TRamAllocFlags aFlags, TZonePageType aZonePageType, 
+					TUint aBlockZoneId, TBool aBlockRest)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocRam(?,%d,%x)",aCount,aFlags));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+#ifdef _DEBUG
+	if(K::CheckForSimulatedAllocFail())
+		{
+		__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocRam returns simulated OOM %d",KErrNoMemory));
+		return KErrNoMemory;
+		}
+#endif
+	TInt missing = iRamPageAllocator->AllocRamPages(aPages, aCount, aZonePageType, aBlockZoneId, aBlockRest);
+	if(missing && !(aFlags&EAllocNoPagerReclaim) && ThePager.GetFreePages(missing))
+		missing = iRamPageAllocator->AllocRamPages(aPages, aCount, aZonePageType, aBlockZoneId, aBlockRest);
+	TInt r = missing ? KErrNoMemory : KErrNone;
+	if(r!=KErrNone)
+		iRamAllocFailed = ETrue;
+	else
+		PagesAllocated(aPages,aCount,aFlags);
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocRam returns %d",r));
+	return r;
+	}
+
+
+void Mmu::FreeRam(TPhysAddr* aPages, TUint aCount, TZonePageType aZonePageType)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::FreeRam(?,%d)",aCount));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+
+	// update page infos...
+	TPhysAddr* pages = aPages;
+	TPhysAddr* pagesEnd = pages+aCount;
+	TPhysAddr* pagesOut = aPages;
+	MmuLock::Lock();
+	TUint flash = 0;
+	while(pages<pagesEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo/2);
+		TPhysAddr pagePhys = *pages++;
+		__NK_ASSERT_DEBUG(pagePhys!=KPhysAddrInvalid);
+		SPageInfo* pi = SPageInfo::FromPhysAddr(pagePhys);
+		PageFreed(pi);
+
+		// If this is an old page of a page being moved that was previously pinned
+		// then make sure it is freed as discardable otherwise despite DPager::DonatePages()
+		// having marked it as discardable it would be freed as movable.
+		__NK_ASSERT_DEBUG(pi->PagedState() != SPageInfo::EPagedPinnedMoved || aCount == 1);
+		if (pi->PagedState() == SPageInfo::EPagedPinnedMoved)
+			aZonePageType = EPageDiscard;
+
+		if(ThePager.PageFreed(pi)==KErrNone)
+			--aCount; // pager has dealt with this page, so one less for us
+		else
+			{
+			// All paged pages should have been dealt with by the pager above.
+			__NK_ASSERT_DEBUG(pi->PagedState() == SPageInfo::EUnpaged);
+			*pagesOut++ = pagePhys; // store page address for freeing later
+			}
+		}
+	MmuLock::Unlock();
+
+	iRamPageAllocator->FreeRamPages(aPages, aCount, aZonePageType);
+	}
+
+
+TInt Mmu::AllocContiguousRam(TPhysAddr& aPhysAddr, TUint aCount, TUint aAlign, TRamAllocFlags aFlags)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocContiguousRam(?,0x%x,%d,%x)",aCount,aAlign,aFlags));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+#ifdef _DEBUG
+	if(K::CheckForSimulatedAllocFail())
+		{
+		__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocContiguousRam returns simulated OOM %d",KErrNoMemory));
+		return KErrNoMemory;
+		}
+	// Only the page sets EAllocNoPagerReclaim and it shouldn't allocate contiguous ram.
+	__NK_ASSERT_DEBUG(!(aFlags&EAllocNoPagerReclaim));
+#endif
+	TInt r = iRamPageAllocator->AllocContiguousRam(aCount, aPhysAddr, EPageFixed, aAlign+KPageShift);
+	if(r==KErrNoMemory && aCount > KMaxFreeableContiguousPages)
+		{
+		// flush paging cache and retry...
+		ThePager.FlushAll();
+		r = iRamPageAllocator->AllocContiguousRam(aCount, aPhysAddr, EPageFixed, aAlign+KPageShift);
+		}
+	if(r!=KErrNone)
+		iRamAllocFailed = ETrue;
+	else
+		PagesAllocated((TPhysAddr*)(aPhysAddr|1), aCount, aFlags);
+	__KTRACE_OPT(KMMU,Kern::Printf("AllocContiguouseRam returns %d and aPhysAddr=0x%08x",r,aPhysAddr));
+	return r;
+	}
+
+
+void Mmu::FreeContiguousRam(TPhysAddr aPhysAddr, TUint aCount)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::FreeContiguousRam(0x%08x,0x%x)",aPhysAddr,aCount));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+	__NK_ASSERT_DEBUG((aPhysAddr&KPageMask)==0);
+
+	TUint pageCount = aCount;
+
+	// update page infos...
+	SPageInfo* pi = SPageInfo::FromPhysAddr(aPhysAddr);
+	SPageInfo* piEnd = pi+pageCount;
+	TUint flash = 0;
+	MmuLock::Lock();
+	while(pi<piEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo);
+		PageFreed(pi++);
+		}
+	MmuLock::Unlock();
+
+	// free pages...
+	while(pageCount)
+		{
+		iRamPageAllocator->FreeRamPage(aPhysAddr, EPageFixed);
+		aPhysAddr += KPageSize;
+		--pageCount;
+		}
+	}
+
+
+TInt Mmu::AllocPhysicalRam(TPhysAddr* aPages, TUint aCount, TRamAllocFlags aFlags)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocPhysicalRam(?,%d,%x)",aCount,aFlags));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+	// Allocate fixed pages as physically allocated pages aren't movable or discardable.
+	TInt r = AllocRam(aPages, aCount, aFlags, EPageFixed);
+	if (r!=KErrNone)
+		return r;
+
+	// update page infos...
+	TPhysAddr* pages = aPages;
+	TPhysAddr* pagesEnd = pages+aCount;
+	MmuLock::Lock();
+	TUint flash = 0;
+	while(pages<pagesEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo/2);
+		TPhysAddr pagePhys = *pages++;
+		__NK_ASSERT_DEBUG(pagePhys!=KPhysAddrInvalid);
+		SPageInfo* pi = SPageInfo::FromPhysAddr(pagePhys);
+		pi->SetPhysAlloc();
+		}
+	MmuLock::Unlock();
+
+	return KErrNone;
+	}
+
+
+void Mmu::FreePhysicalRam(TPhysAddr* aPages, TUint aCount)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::FreePhysicalRam(?,%d)",aCount));
+	__NK_ASSERT_DEBUG(RamAllocLock::IsHeld());
+
+	// update page infos...
+	TPhysAddr* pages = aPages;
+	TPhysAddr* pagesEnd = pages+aCount;
+	MmuLock::Lock();
+	TUint flash = 0;
+	while(pages<pagesEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo/2);
+		TPhysAddr pagePhys = *pages++;
+		__NK_ASSERT_DEBUG(pagePhys!=KPhysAddrInvalid);
+		SPageInfo* pi = SPageInfo::FromPhysAddr(pagePhys);
+		__ASSERT_ALWAYS(pi->Type()==SPageInfo::EPhysAlloc, Panic(EBadFreePhysicalRam));
+		__ASSERT_ALWAYS(!pi->UseCount(), Panic(EBadFreePhysicalRam));
+		pi->SetUnused();
+		}
+	MmuLock::Unlock();
+
+	iRamPageAllocator->FreeRamPages(aPages,aCount, EPageFixed);
+	}
+
+
+TInt Mmu::AllocPhysicalRam(TPhysAddr& aPhysAddr, TUint aCount, TUint aAlign, TRamAllocFlags aFlags)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocPhysicalRam(?,0x%x,d,%x)",aCount,aAlign,aFlags));
+	TInt r = AllocContiguousRam(aPhysAddr,aCount,aAlign,aFlags);
+	if (r!=KErrNone)
+		return r;
+
+	// update page infos...
+	SPageInfo* pi = SPageInfo::FromPhysAddr(aPhysAddr);
+	SPageInfo* piEnd = pi+aCount;
+	TUint flash = 0;
+	MmuLock::Lock();
+	while(pi<piEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo);
+		pi->SetPhysAlloc();
+		++pi;
+		}
+	MmuLock::Unlock();
+
+	return KErrNone;
+	}
+
+
+void Mmu::FreePhysicalRam(TPhysAddr aPhysAddr, TUint aCount)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::FreePhysicalRam(0x%08x,0x%x)",aPhysAddr,aCount));
+
+	// update page infos...
+	SPageInfo* pi = SPageInfo::FromPhysAddr(aPhysAddr);
+	SPageInfo* piEnd = pi+aCount;
+	TUint flash = 0;
+	MmuLock::Lock();
+	while(pi<piEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo);
+		__ASSERT_ALWAYS(pi->Type()==SPageInfo::EPhysAlloc, Panic(EBadFreePhysicalRam));
+		__ASSERT_ALWAYS(!pi->UseCount(), Panic(EBadFreePhysicalRam));
+		pi->SetUnused();
+		++pi;
+		}
+	MmuLock::Unlock();
+
+	iRamPageAllocator->FreePhysicalRam(aPhysAddr, aCount << KPageShift);
+	}
+
+
+TInt Mmu::ClaimPhysicalRam(TPhysAddr aPhysAddr, TUint aCount, TRamAllocFlags aFlags)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::ClaimPhysicalRam(0x%08x,0x%x,0x%08x)",aPhysAddr,aCount,aFlags));
+	aPhysAddr &= ~KPageMask;
+	TInt r = iRamPageAllocator->ClaimPhysicalRam(aPhysAddr,(aCount << KPageShift));
+	if(r!=KErrNone)
+		return r;
+
+	PagesAllocated((TPhysAddr*)(aPhysAddr|1), aCount, aFlags);
+
+	// update page infos...
+	SPageInfo* pi = SPageInfo::FromPhysAddr(aPhysAddr);
+	SPageInfo* piEnd = pi+aCount;
+	TUint flash = 0;
+	MmuLock::Lock();
+	while(pi<piEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo);
+		pi->SetPhysAlloc();
+		++pi;
+		}
+	MmuLock::Unlock();
+
+	return KErrNone;
+	}
+
+
+void Mmu::AllocatedPhysicalRam(TPhysAddr aPhysAddr, TUint aCount, TRamAllocFlags aFlags)
+	{
+	__KTRACE_OPT(KMMU,Kern::Printf("Mmu::AllocatedPhysicalRam(0x%08x,0x%x,d,%x)",aPhysAddr,aCount,aFlags));
+
+	PagesAllocated((TPhysAddr*)(aPhysAddr|1), aCount, aFlags);
+
+	// update page infos...
+	SPageInfo* pi = SPageInfo::FromPhysAddr(aPhysAddr);
+	SPageInfo* piEnd = pi+aCount;
+	TUint flash = 0;
+	MmuLock::Lock();
+	while(pi<piEnd)
+		{
+		MmuLock::Flash(flash,KMaxPageInfoUpdatesInOneGo);
+		pi->SetPhysAlloc();
+		++pi;
+		}
+	MmuLock::Unlock();
+	}
+
+
+//
+// Misc
+//
+
+#ifdef _DEBUG
+/**
+Perform a page table walk to return the physical address of
+the memory mapped at virtual address \a aLinAddr in the
+address space \a aOsAsid.
+
+If the page table used was not one allocated by the kernel
+then the results are unpredictable and may cause a system fault.
+
+@pre #MmuLock held.
+*/
+TPhysAddr Mmu::LinearToPhysical(TLinAddr aLinAddr, TInt aOsAsid)
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld() || K::Initialising);
+	return UncheckedLinearToPhysical(aLinAddr,aOsAsid);
+	}
+#endif
+
+
+/**
+Next virtual address available for allocation by TTempMapping.
+This is initialised to #KTempAddr and addresses may be allocated
+until they reach #KTempAddrEnd.
+*/
+TLinAddr Mmu::TTempMapping::iNextLinAddr = KTempAddr;
+
+
+/**
+Allocate virtual address space required to map a given number of memory pages.
+
+The actual size of allocated virtual allocated needs to accommodate \a aNumPages
+number of pages of any colour. For example: if \a aNumPages == 4 and #KPageColourCount == 4,
+then at least 7 pages are required. 
+
+@param aNumPages	Maximum number of pages that can be mapped into this temporary mapping.
+
+@pre Called in single threaded content (boot) only.
+
+@pre #iNextLinAddr points to virtual page with zero colour.
+@post #iNextLinAddr points to virtual page with zero colour.
+*/
+void Mmu::TTempMapping::Alloc(TUint aNumPages)
+	{
+	__NK_ASSERT_DEBUG(aNumPages<=(KTempAddrEnd-KTempAddr)/KPageSize);
+
+	// This runs during the boot only (single threaded context) so the access to iNextLinAddr is not guarded by any mutex.
+	TLinAddr tempAddr = iNextLinAddr;
+	TUint numPages = (KPageColourMask+aNumPages+KPageColourMask)&~KPageColourMask;
+	iNextLinAddr = tempAddr+numPages*KPageSize;
+
+	__NK_ASSERT_ALWAYS(iNextLinAddr<=KTempAddrEnd);
+
+	__NK_ASSERT_DEBUG(iSize==0);
+	iLinAddr = tempAddr;
+	MmuLock::Lock();
+	iPtePtr = Mmu::PtePtrFromLinAddr(tempAddr,KKernelOsAsid);
+	__NK_ASSERT_DEBUG(iPtePtr);
+	MmuLock::Unlock();
+	iBlankPte = TheMmu.iTempPteCached;
+	iSize = aNumPages;
+	iCount = 0;
+
+	TRACEB(("Mmu::TTempMapping::Alloc(%d) iLinAddr=0x%08x, iPtePtr=0x%08x",aNumPages,iLinAddr,iPtePtr));
+	}
+
+
+/**
+Map a single physical page into this temporary mapping.
+
+Supervisor read/write access and EMemoryAttributeStandard memory attributes apply.
+
+@param aPage		The physical page to map.
+@param aColour 		The required colour for the mapping.
+
+@return 			The linear address at which the page is mapped.
+*/
+TLinAddr Mmu::TTempMapping::Map(TPhysAddr aPage, TUint aColour)
+	{
+	__NK_ASSERT_DEBUG(iSize>=1);
+	__NK_ASSERT_DEBUG(iCount==0);
+
+	TUint colour = aColour&KPageColourMask;
+	TLinAddr addr = iLinAddr+(colour<<KPageShift);
+	TPte* pPte = iPtePtr+colour;
+	iColour = colour;
+
+	__ASSERT_DEBUG(*pPte==KPteUnallocatedEntry,MM::Panic(MM::ETempMappingAlreadyInUse));
+	*pPte = (aPage&~KPageMask) | iBlankPte;
+	CacheMaintenance::SinglePteUpdated((TLinAddr)pPte);
+	InvalidateTLBForPage(addr|KKernelOsAsid);
+
+	iCount = 1;
+	return addr;
+	}
+
+/**
+Map a single physical page into this temporary mapping using the given page table entry (PTE) value.
+
+@param aPage		The physical page to map.
+@param aColour 		The required colour for the mapping.
+@param aBlankPte	The PTE value to use for mapping the page,
+					with the physical address component equal to zero.
+
+@return 			The linear address at which the page is mapped.
+*/
+TLinAddr Mmu::TTempMapping::Map(TPhysAddr aPage, TUint aColour, TPte aBlankPte)
+	{
+	__NK_ASSERT_DEBUG(iSize>=1);
+	__NK_ASSERT_DEBUG(iCount==0);
+
+	TUint colour = aColour&KPageColourMask;
+	TLinAddr addr = iLinAddr+(colour<<KPageShift);
+	TPte* pPte = iPtePtr+colour;
+	iColour = colour;
+
+	__ASSERT_DEBUG(*pPte==KPteUnallocatedEntry,MM::Panic(MM::ETempMappingAlreadyInUse));
+	*pPte = (aPage&~KPageMask) | aBlankPte;
+	CacheMaintenance::SinglePteUpdated((TLinAddr)pPte);
+	InvalidateTLBForPage(addr|KKernelOsAsid);
+
+	iCount = 1;
+	return addr;
+	}
+
+
+/**
+Map a number of physical pages into this temporary mapping.
+
+Supervisor read/write access and EMemoryAttributeStandard memory attributes apply.
+
+@param aPages		The array of physical pages to map.
+@param aCount		The number of pages to map.
+@param aColour 		The required colour for the first page.
+					Consecutive pages will be coloured accordingly.
+
+@return 			The linear address at which the first page is mapped.
+*/
+TLinAddr Mmu::TTempMapping::Map(TPhysAddr* aPages, TUint aCount, TUint aColour)
+	{
+	__NK_ASSERT_DEBUG(iSize>=aCount);
+	__NK_ASSERT_DEBUG(iCount==0);
+
+	TUint colour = aColour&KPageColourMask;
+	TLinAddr addr = iLinAddr+(colour<<KPageShift);
+	TPte* pPte = iPtePtr+colour;
+	iColour = colour;
+
+	for(TUint i=0; i<aCount; ++i)
+		{
+		__ASSERT_DEBUG(pPte[i]==KPteUnallocatedEntry,MM::Panic(MM::ETempMappingAlreadyInUse));
+		pPte[i] = (aPages[i]&~KPageMask) | iBlankPte;
+		CacheMaintenance::SinglePteUpdated((TLinAddr)&pPte[i]);
+		InvalidateTLBForPage((addr+i*KPageSize)|KKernelOsAsid);
+		}
+
+	iCount = aCount;
+	return addr;
+	}
+
+
+/**
+Unmap all pages from this temporary mapping.
+
+@param aIMBRequired	True if IMB barrier is required prior unmapping.
+*/
+void Mmu::TTempMapping::Unmap(TBool aIMBRequired)
+	{
+	__NK_ASSERT_DEBUG(iSize>=1);
+	if(aIMBRequired)
+		CacheMaintenance::CodeChanged(iLinAddr+iColour*KPageSize,iCount*KPageSize);
+	Unmap();
+	}
+
+
+/**
+Unmap all pages from this temporary mapping.
+*/
+void Mmu::TTempMapping::Unmap()
+	{
+	__NK_ASSERT_DEBUG(iSize>=1);
+
+	TUint colour = iColour;
+	TLinAddr addr = iLinAddr+(colour<<KPageShift);
+	TPte* pPte = iPtePtr+colour;
+	TUint count = iCount;
+
+	while(count)
+		{
+		*pPte = KPteUnallocatedEntry;
+		CacheMaintenance::SinglePteUpdated((TLinAddr)pPte);
+		InvalidateTLBForPage(addr|KKernelOsAsid);
+		addr += KPageSize;
+		++pPte;
+		--count;
+		}
+
+	iCount = 0;
+	}
+
+
+/**
+Remove any thread IPC aliases which use the specified page table.
+This is used by the page table allocator when a page table is freed.
+
+@pre #PageTablesLockIsHeld
+*/
+void Mmu::RemoveAliasesForPageTable(TPhysAddr aPageTable)
+	{
+	__NK_ASSERT_DEBUG(PageTablesLockIsHeld());
+
+	MmuLock::Lock();
+
+	SDblQue checkedList;
+
+	TUint ptId = aPageTable>>KPageTableShift;
+	while(!iAliasList.IsEmpty())
+		{
+		SDblQueLink* next = iAliasList.First()->Deque();
+		checkedList.Add(next);
+		DMemModelThread* thread = (DMemModelThread*)((TInt)next-_FOFF(DMemModelThread,iAliasLink));
+		if((thread->iAliasPde>>KPageTableShift)==ptId)
+			{
+			// the page table is being aliased by the thread, so remove it...
+			TRACE2(("Thread %O RemoveAliasesForPageTable", this));
+			thread->iAliasPde = KPdeUnallocatedEntry;
+#ifdef __SMP__ // we need to also unmap the page table in case thread is running on another core...
+			// need Data Memory Barrier (DMB) here to make sure iAliasPde change is
+			// seen before we set the PDE entry, otherwise 'thread' may read old value
+			// and put it back
+			__e32_memory_barrier();
+			*thread->iAliasPdePtr = KPdeUnallocatedEntry;
+			SinglePdeUpdated(thread->iAliasPdePtr);
+			__NK_ASSERT_DEBUG((thread->iAliasLinAddr&KPageMask)==0);
+			// Invalidate the tlb for the page using os asid of the process that created the alias
+			// this is safe as the os asid will be valid as thread must be running otherwise the alias
+			// would have been removed.
+			InvalidateTLBForPage(thread->iAliasLinAddr | ((DMemModelProcess*)thread->iOwningProcess)->OsAsid());
+			// note, race condition with 'thread' updating its iAliasLinAddr is
+			// not a problem because 'thread' will not the be accessing the aliased
+			// region and will take care of invalidating the TLB.
+			// FIXME: There is still a race here. If the thread owning the alias reads the
+			// PDE before we clear thread->iAliasPde and writes it after we clear
+			// *thread->iAliasPdePtr the alias still ends up restored when it shouldn't be.
+#endif
+			}
+		MmuLock::Flash();
+		}
+
+	// copy checkedList back to iAliasList
+	iAliasList.MoveFrom(&checkedList);
+
+	MmuLock::Unlock();
+	}
+
+
+void DMemModelThread::RefreshAlias()
+	{
+	if(iAliasLinAddr)
+		{
+		TRACE2(("Thread %O RefreshAlias", this));
+		// Get the os asid, this is the current thread so no need to open a reference.
+		TUint thisAsid = ((DMemModelProcess*)iOwningProcess)->OsAsid();
+		MmuLock::Lock();
+		TInt osAsid = iAliasProcess->OsAsid();
+		TPde pde = *Mmu::PageDirectoryEntry(osAsid,iAliasTarget);
+		iAliasPde = pde;
+		*iAliasPdePtr = pde;
+		SinglePdeUpdated(iAliasPdePtr);
+		InvalidateTLBForPage(iAliasLinAddr|thisAsid);
+		MmuLock::Unlock();
+		}
+	}
+
+
+
+//
+// Mapping/unmapping functions
+//
+
+
+/**
+Modify page table entries (PTEs) so they map the given memory pages.
+Entries are only updated if the current state of the corresponding page
+is RPageArray::ECommitted.
+
+@param aPtePtr		Pointer into a page table for the PTE of the first page.
+@param aCount		The number of pages to modify.
+@param aPages		Pointer to the entry for the first page in a memory object's #RPageArray.
+					Each entry contains the physical address of a page together with its
+					current state (RPageArray::TState).
+@param aBlankPte	The value to use for each PTE, with the physical address component equal
+					to zero.
+
+@return False, if the page table no longer maps any entries and may be freed.
+		True otherwise, to indicate that the page table is still needed.
+
+@pre #MmuLock held.
+@post #MmuLock held and has not been released by this function.
+*/
+TBool Mmu::MapPages(TPte* const aPtePtr, const TUint aCount, TPhysAddr* aPages, TPte aBlankPte)
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld());
+	__NK_ASSERT_DEBUG(aCount);
+ 	__NK_ASSERT_DEBUG(aBlankPte!=KPteUnallocatedEntry);
+
+	TUint count = 0;
+	if(aCount==1)
+		{
+		// get page to map...
+		TPhysAddr pagePhys = *aPages;
+		TPte pte = *aPtePtr;
+		if(!RPageArray::TargetStateIsCommitted(pagePhys))
+			goto done; // page no longer needs mapping
+
+		// clear type flags...
+		pagePhys &= ~KPageMask;
+	
+		// check nobody has already mapped the page...
+		if(pte!=KPteUnallocatedEntry)
+			{
+			// already mapped...
+#ifdef _DEBUG
+			if((pte^pagePhys)>=TPte(KPageSize))
+				{
+				// but different!
+				Kern::Printf("Mmu::MapPages already mapped %x->%x",pagePhys,pte);
+				__NK_ASSERT_DEBUG(0);
+				}
+#endif
+			return true; // return true to keep page table (it already had at least page mapped)
+			}
+
+		// map page...
+		pte = pagePhys|aBlankPte;
+		TRACE2(("!PTE %x=%x",aPtePtr,pte));
+		*aPtePtr = pte;
+		count = 1;
+
+		// clean cache...
+		CacheMaintenance::SinglePteUpdated((TLinAddr)aPtePtr);
+		}
+	else
+		{
+		// check we are only updating a single page table...
+		__NK_ASSERT_DEBUG(((TLinAddr(aPtePtr)^TLinAddr(aPtePtr+aCount-1))>>KPageTableShift)==0);
+
+		// map pages...
+		TPte* pPte = aPtePtr;
+		TPte* pPteEnd = aPtePtr+aCount;
+		do
+			{
+			// map page...
+			TPhysAddr pagePhys = *aPages++;
+			TPte pte = *pPte++;
+			if(RPageArray::TargetStateIsCommitted(pagePhys))
+				{
+				// clear type flags...
+				pagePhys &= ~KPageMask;
+
+				// page not being freed, so try and map it...
+				if(pte!=KPteUnallocatedEntry)
+					{
+					// already mapped...
+#ifdef _DEBUG
+					if((pte^pagePhys)>=TPte(KPageSize))
+						{
+						// but different!
+						Kern::Printf("Mmu::MapPages already mapped %x->%x",pagePhys,pte);
+						__NK_ASSERT_DEBUG(0);
+						}
+#endif
+					}
+				else
+					{
+					// map page...
+					pte = pagePhys|aBlankPte;
+					TRACE2(("!PTE %x=%x",pPte-1,pte));
+					pPte[-1] = pte;
+					++count;
+					}
+				}
+			}
+		while(pPte!=pPteEnd);
+
+		// clean cache...
+		CacheMaintenance::MultiplePtesUpdated((TLinAddr)aPtePtr,(TLinAddr)pPte-(TLinAddr)aPtePtr);
+		}
+
+done:
+	// update page counts...
+	SPageTableInfo* pti = SPageTableInfo::FromPtPtr(aPtePtr);
+	count = pti->IncPageCount(count);
+	TRACE2(("pt %x page count=%d",TLinAddr(aPtePtr)&~KPageTableMask,pti->PageCount()));
+	__NK_ASSERT_DEBUG(pti->CheckPageCount());
+
+	// see if page table needs freeing...
+	TUint keepPt = count | pti->PermanenceCount();
+
+	__NK_ASSERT_DEBUG(!pti->IsDemandPaged()); // check not demand paged page table
+
+	return keepPt;
+	}
+
+
+/**
+Modify page table entries (PTEs) so they map a new page.
+Entries are only updated if the current state of the corresponding page
+is RPageArray::ECommitted or RPageArray::EMoving.
+
+@param aPtePtr		Pointer into a page table for the PTE of the page.
+@param aPage		Pointer to the entry for the page in a memory object's #RPageArray.
+					The entry contains the physical address of a page together with its
+					current state (RPageArray::TState).
+@param aBlankPte	The value to use for each PTE, with the physical address component equal
+					to zero.
+
+@pre #MmuLock held.
+@post #MmuLock held and has not been released by this function.
+*/
+void Mmu::RemapPage(TPte* const aPtePtr, TPhysAddr& aPage, TPte aBlankPte)
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld());
+ 	__NK_ASSERT_DEBUG(aBlankPte!=KPteUnallocatedEntry);
+
+	// get page to remap...
+	TPhysAddr pagePhys = aPage;
+	
+	// Only remap the page if it is committed or it is being moved and
+	// no other operation has been performed on the page.
+	if(!RPageArray::TargetStateIsCommitted(pagePhys))
+		return; // page no longer needs mapping
+	
+	// Only remap the page if it is currently mapped, i.e. doesn't have an unallocated pte.
+	// This will only be true if a new mapping is being added but it hasn't yet updated 
+	// all the ptes for the pages that it maps.
+	TPte pte = *aPtePtr;
+	if (pte == KPteUnallocatedEntry)
+		return;
+	
+	// clear type flags...
+	pagePhys &= ~KPageMask;
+
+	SPageInfo* pi = SPageInfo::SafeFromPhysAddr(pagePhys);
+	if (pi)
+		{
+		SPageInfo::TPagedState pagedState = pi->PagedState();
+		if (pagedState != SPageInfo::EUnpaged)
+			{
+			// The page is demand paged.  Only remap the page if it is pinned or is currently
+			// accessible but to the old physical page.
+			if (pagedState != SPageInfo::EPagedPinned &&
+				 (Mmu::IsPteInaccessible(pte) || (pte^pagePhys) < TPte(KPageSize)))
+				return;
+			if (!pi->IsDirty())
+				{
+				// Ensure that the page is mapped as read only to prevent pages being marked dirty
+				// by page moving despite not having been written to
+				Mmu::MakePteInaccessible(aBlankPte, EFalse);
+				}
+			}
+		}
+	
+	// Map the page in the page array entry as this is always the physical
+	// page that the memory object's page should be mapped to.
+	pte = pagePhys|aBlankPte;
+	TRACE2(("!PTE %x=%x",aPtePtr,pte));
+	*aPtePtr = pte;
+	
+	// clean cache...
+	CacheMaintenance::SinglePteUpdated((TLinAddr)aPtePtr);
+	}
+
+
+/**
+Modify page table entries (PTEs) so they no longer map any memory pages.
+
+@param aPtePtr		Pointer into a page table for the PTE of the first page.
+@param aCount		The number of pages to modify.
+
+@return False, if the page table no longer maps any entries and may be freed.
+		True otherwise, to indicate that the page table is still needed.
+
+@pre #MmuLock held.
+@post #MmuLock held and has not been released by this function.
+*/
+TBool Mmu::UnmapPages(TPte* const aPtePtr, TUint aCount)
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld());
+	__NK_ASSERT_DEBUG(aCount);
+
+	TUint count = 0;
+	if(aCount==1)
+		{
+		if(*aPtePtr==KPteUnallocatedEntry)
+			return true; // page already unmapped
+
+		// unmap page...
+		++count;
+		TPte pte = KPteUnallocatedEntry;
+		TRACE2(("!PTE %x=%x",aPtePtr,pte));
+		*aPtePtr = pte;
+
+		// clean cache...
+		CacheMaintenance::SinglePteUpdated((TLinAddr)aPtePtr);
+		}
+	else
+		{
+		// check we are only updating a single page table...
+		__NK_ASSERT_DEBUG(((TLinAddr(aPtePtr)^TLinAddr(aPtePtr+aCount-1))>>KPageTableShift)==0);
+
+		// unmap pages...
+		TPte* pPte = aPtePtr;
+		TPte* pPteEnd = aPtePtr+aCount;
+		do
+			{
+			if(*pPte!=KPteUnallocatedEntry)
+				{
+				// unmap page...
+				++count;
+				TPte pte = KPteUnallocatedEntry;
+				TRACE2(("!PTE %x=%x",pPte,pte));
+				*pPte = pte;
+				}
+			}
+		while(++pPte<pPteEnd);
+
+		if(!count)
+			return true; // no PTEs changed, so nothing more to do
+
+		// clean cache...
+		CacheMaintenance::MultiplePtesUpdated((TLinAddr)aPtePtr,(TLinAddr)pPte-(TLinAddr)aPtePtr);
+		}
+
+	// update page table info...
+	SPageTableInfo* pti = SPageTableInfo::FromPtPtr(aPtePtr);
+	count = pti->DecPageCount(count);
+	TRACE2(("pt %x page count=%d",TLinAddr(aPtePtr)&~KPageTableMask,count));
+	__NK_ASSERT_DEBUG(pti->CheckPageCount());
+
+	// see if page table needs freeing...
+	TUint keepPt = count | pti->PermanenceCount();
+
+	return keepPt;
+	}
+
+
+/**
+Modify page table entries (PTEs) so they no longer map the given memory pages.
+Entries are only updated if the current state of the corresponding page
+is 'decommitted' i.e. RPageArray::TargetStateIsDecommitted returns true.
+
+@param aPtePtr		Pointer into a page table for the PTE of the first page.
+@param aCount		The number of pages to modify.
+@param aPages		Pointer to the entry for the first page in a memory object's #RPageArray.
+					Each entry contains the physical address of a page together with its
+					current state (RPageArray::TState).
+
+@return False, if the page table no longer maps any entries and may be freed.
+		True otherwise, to indicate that the page table is still needed.
+
+@pre #MmuLock held.
+@post #MmuLock held and has not been released by this function.
+*/
+TBool Mmu::UnmapPages(TPte* const aPtePtr, TUint aCount, TPhysAddr* aPages)
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld());
+	__NK_ASSERT_DEBUG(aCount);
+
+	TUint count = 0;
+	if(aCount==1)
+		{
+		if(*aPtePtr==KPteUnallocatedEntry)
+			return true; // page already unmapped
+
+		if(!RPageArray::TargetStateIsDecommitted(*aPages))
+			return true; // page has been reallocated
+
+		// unmap page...
+		++count;
+		TPte pte = KPteUnallocatedEntry;
+		TRACE2(("!PTE %x=%x",aPtePtr,pte));
+		*aPtePtr = pte;
+
+		// clean cache...
+		CacheMaintenance::SinglePteUpdated((TLinAddr)aPtePtr);
+		}
+	else
+		{
+		// check we are only updating a single page table...
+		__NK_ASSERT_DEBUG(((TLinAddr(aPtePtr)^TLinAddr(aPtePtr+aCount-1))>>KPageTableShift)==0);
+
+		// unmap pages...
+		TPte* pPte = aPtePtr;
+		TPte* pPteEnd = aPtePtr+aCount;
+		do
+			{
+			if(RPageArray::TargetStateIsDecommitted(*aPages++) && *pPte!=KPteUnallocatedEntry)
+				{
+				// unmap page...
+				++count;
+				TPte pte = KPteUnallocatedEntry;
+				TRACE2(("!PTE %x=%x",pPte,pte));
+				*pPte = pte;
+				}
+			}
+		while(++pPte<pPteEnd);
+
+		if(!count)
+			return true; // no PTEs changed, so nothing more to do
+
+		// clean cache...
+		CacheMaintenance::MultiplePtesUpdated((TLinAddr)aPtePtr,(TLinAddr)pPte-(TLinAddr)aPtePtr);
+		}
+
+	// update page table info...
+	SPageTableInfo* pti = SPageTableInfo::FromPtPtr(aPtePtr);
+	count = pti->DecPageCount(count);
+	TRACE2(("pt %x page count=%d",TLinAddr(aPtePtr)&~KPageTableMask,count));
+	__NK_ASSERT_DEBUG(pti->CheckPageCount());
+
+	// see if page table needs freeing...
+	TUint keepPt = count | pti->PermanenceCount();
+
+	return keepPt;
+	}
+
+
+/**
+Modify page table entries (PTEs) so the given memory pages are not accessible.
+Entries are only updated if the current state of the corresponding page
+is RPageArray::ERestrictingNA.
+
+@param aPtePtr		Pointer into a page table for the PTE of the first page.
+@param aCount		The number of pages to modify.
+@param aPages		Pointer to the entry for the first page in a memory object's #RPageArray.
+					Each entry contains the physical address of a page together with its
+					current state (RPageArray::TState).
+
+@pre #MmuLock held.
+@post #MmuLock held and has not been released by this function.
+*/
+void Mmu::RestrictPagesNA(TPte* const aPtePtr, TUint aCount, TPhysAddr* aPages)
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld());
+	__NK_ASSERT_DEBUG(aCount);
+
+	if(aCount==1)
+		{
+		TPhysAddr page = *aPages;
+		TPte pte = *aPtePtr;
+		RPageArray::TState state = RPageArray::State(page);
+		if(state != RPageArray::ERestrictingNA && state != RPageArray::EMoving)
+			return; // page no longer needs restricting
+
+		if(pte==KPteUnallocatedEntry)
+			return; // page gone
+
+		// restrict page...
+		pte = Mmu::MakePteInaccessible(pte,false);
+		TRACE2(("!PTE %x=%x",aPtePtr,pte));
+		*aPtePtr = pte;
+
+		// clean cache...
+		CacheMaintenance::SinglePteUpdated((TLinAddr)aPtePtr);
+		}
+	else
+		{
+		// check we are only updating a single page table...
+		__NK_ASSERT_DEBUG(((TLinAddr(aPtePtr)^TLinAddr(aPtePtr+aCount-1))>>KPageTableShift)==0);
+
+		// restrict pages...
+		TPte* pPte = aPtePtr;
+		TPte* pPteEnd = aPtePtr+aCount;
+		do
+			{
+			TPhysAddr page = *aPages++;
+			TPte pte = *pPte++;
+			if(RPageArray::State(page)==RPageArray::ERestrictingNA && pte!=KPteUnallocatedEntry)
+				{
+				pte = Mmu::MakePteInaccessible(pte,false);
+				TRACE2(("!PTE %x=%x",pPte-1,pte));
+				pPte[-1] = pte;
+				}
+			}
+		while(pPte<pPteEnd);
+
+		// clean cache...
+		CacheMaintenance::MultiplePtesUpdated((TLinAddr)aPtePtr,(TLinAddr)pPte-(TLinAddr)aPtePtr);
+		}
+	}
+
+
+/**
+Modify page table entries (PTEs) so they map the given demand paged memory pages.
+
+Entries are only updated if the current state of the corresponding page
+is RPageArray::ECommitted.
+
+This function is used for demand paged memory when handling a page fault or
+memory pinning operation. It will widen the access permission of existing entries
+if required to match \a aBlankPte and will 'rejuvenate' the page table.
+
+@param aPtePtr		Pointer into a page table for the PTE of the first page.
+@param aCount		The number of pages to modify.
+@param aPages		Pointer to the entry for the first page in a memory object's #RPageArray.
+					Each entry contains the physical address of a page together with its
+					current state (RPageArray::TState).
+@param aBlankPte	The value to use for each PTE, with the physical address component equal
+					to zero.
+
+@return False, if the page table no longer maps any entries and may be freed.
+		True otherwise, to indicate that the page table is still needed.
+
+@pre #MmuLock held.
+@post MmuLock held (but may have been released by this function)
+*/
+TBool Mmu::PageInPages(TPte* const aPtePtr, const TUint aCount, TPhysAddr* aPages, TPte aBlankPte)
+	{
+	__NK_ASSERT_DEBUG(MmuLock::IsHeld());
+	__NK_ASSERT_DEBUG(aCount);
+	__NK_ASSERT_DEBUG(aBlankPte!=KPteUnallocatedEntry);
+
+	TUint count = 0;
+
+	if(aCount==1)
+		{
+		// get page to map...
+		TPhysAddr page = *aPages;
+		TPte pte = *aPtePtr;
+		if(!RPageArray::TargetStateIsCommitted(page))
+			goto done; // page no longer needs mapping
+
+#ifdef _DEBUG
+		if(pte!=KPteUnallocatedEntry)
+			{
+			if ((pte^page)>=TPte(KPageSize) && !Mmu::IsPteInaccessible(pte) &&
+				!Mmu::IsPteReadOnly(pte))
+				{
+				// Page has been mapped before but the physical address is different
+				// and the page hasn't been moved as it is not inaccessible.
+				Kern::Printf("Mmu::PageInPages already mapped %x->%x",page,pte);
+				__NK_ASSERT_DEBUG(0);
+				}
+			}
+#endif
+		if(!Mmu::IsPteMoreAccessible(aBlankPte,pte))
+			return true; // return true to keep page table (it already had at least page mapped)
+
+		// remap page with new increased permissions...
+		if(pte==KPteUnallocatedEntry)
+			count = 1; // we'll be adding a new pte entry, count it
+		if(!Mmu::IsPteReadOnly(aBlankPte))
+			ThePager.SetWritable(*SPageInfo::FromPhysAddr(page));
+		pte = (page&~KPageMask)|aBlankPte;
+		TRACE2(("!PTE %x=%x",aPtePtr,pte));
+		*aPtePtr = pte;
+
+		// clean cache...
+		CacheMaintenance::SinglePteUpdated((TLinAddr)aPtePtr);
+		}
+	else
+		{
+		// check we are only updating a single page table...
+		__NK_ASSERT_DEBUG(((TLinAddr(aPtePtr)^TLinAddr(aPtePtr+aCount-1))>>KPageTableShift)==0);
+
+		// map pages...
+		TPte* pPte = aPtePtr;
+		TPte* pPteEnd = aPtePtr+aCount;
+		do
+			{
+			// map page...
+			TPhysAddr page = *aPages++;
+			TPte pte = *pPte++;
+			if(RPageArray::TargetStateIsCommitted(page))
+				{
+#ifdef _DEBUG
+				if(pte!=KPteUnallocatedEntry)
+					{
+					if ((pte^page)>=TPte(KPageSize) && !Mmu::IsPteInaccessible(pte) &&
+						!Mmu::IsPteReadOnly(pte))
+						{
+						// Page has been mapped before but the physical address is different
+						// and the page hasn't been moved as it is not inaccessible.
+						Kern::Printf("Mmu::PageInPages already mapped %x->%x",page,pte);
+						__NK_ASSERT_DEBUG(0);
+						}
+					}
+#endif
+				if(Mmu::IsPteMoreAccessible(aBlankPte,pte))
+					{
+					// remap page with new increased permissions...
+					if(pte==KPteUnallocatedEntry)
+						++count; // we'll be adding a new pte entry, count it
+					if(!Mmu::IsPteReadOnly(aBlankPte))
+						ThePager.SetWritable(*SPageInfo::FromPhysAddr(page));
+					pte = (page&~KPageMask)|aBlankPte;
+					TRACE2(("!PTE %x=%x",pPte-1,pte));
+					pPte[-1] = pte;
+					}
+				}
+			}
+		while(pPte!=pPteEnd);
+
+		// clean cache...
+		CacheMaintenance::MultiplePtesUpdated((TLinAddr)aPtePtr,(TLinAddr)pPte-(TLinAddr)aPtePtr);
+		}
+
+done:
+	// update page counts...
+	SPageTableInfo* pti = SPageTableInfo::FromPtPtr(aPtePtr);
+	count = pti->IncPageCount(count);
+	TRACE2(("pt %x page count=%d",TLinAddr(aPtePtr)&~KPageTableMask,pti->PageCount()));
+	__NK_ASSERT_DEBUG(pti->CheckPageCount());
+
+	// see if page table needs freeing...
+	TUint keepPt = count | pti->PermanenceCount();
+
+	// rejuvenate demand paged page tables...
+	ThePager.RejuvenatePageTable(aPtePtr);
+
+	return keepPt;
+	}
+
+
+//
+// CodeModifier
+//
+
+#ifdef __DEBUGGER_SUPPORT__
+
+void DoWriteCode(TUint32* aAddress, TUint32 aValue);
+
+#ifdef __SMP__
+
+extern "C" void __e32_instruction_barrier();
+
+class TCodeModifierBroadcast : public TGenericIPI
+	{
+public:
+	TCodeModifierBroadcast(TUint32* aAddress, TUint32 aValue);
+	static void Isr(TGenericIPI*);
+	void Go();
+public:
+	TUint32*		iAddress;
+	TUint32			iValue;
+	volatile TInt	iFlag;
+	};
+
+TCodeModifierBroadcast::TCodeModifierBroadcast(TUint32* aAddress, TUint32 aValue)
+	:	iAddress(aAddress), iValue(aValue), iFlag(0)
+	{
+	}
+
+void TCodeModifierBroadcast::Isr(TGenericIPI* aPtr)
+	{
+	TCodeModifierBroadcast& a = *(TCodeModifierBroadcast*)aPtr;
+	while (!__e32_atomic_load_acq32(&a.iFlag))
+		__chill();
+#ifdef __BROADCAST_CACHE_MAINTENANCE__
+	CacheMaintenance::CodeChanged((TLinAddr)a.iAddress, sizeof (TInt), CacheMaintenance::ECodeModifier);	// need to do separate Clean-D, Purge-I on each core
+#else
+	__e32_instruction_barrier();		// synchronize instruction execution
+#endif
+	}
+
+void TCodeModifierBroadcast::Go()
+	{
+	NKern::Lock();
+	QueueAllOther(&Isr);
+	WaitEntry();					// wait for other cores to stop
+	DoWriteCode(iAddress, iValue);
+	iFlag = 1;
+	__e32_instruction_barrier();	// synchronize instruction execution
+	WaitCompletion();				// wait for other cores to resume
+	NKern::Unlock();
+	}
+#endif
+
+/**
+@pre Calling thread must be in critical section
+@pre CodeSeg mutex held
+*/
+TInt CodeModifier::SafeWriteCode(DProcess* aProcess, TLinAddr aAddress, TInt aSize, TUint aValue, void* aOldValue)
+	{
+	__ASSERT_CRITICAL;
+	Mmu& m=TheMmu;
+	RamAllocLock::Lock();
+	MmuLock::Lock();
+	__UNLOCK_GUARD_START(MmuLock);
+
+	// Check aProcess is still alive by opening a reference on its os asid.
+	TInt osAsid = ((DMemModelProcess*)aProcess)->TryOpenOsAsid();
+	if (osAsid < 0)
+		{
+		__KTRACE_OPT(KDEBUGGER,Kern::Printf("CodeModifier::SafeWriteCode - zombie process"));
+		__UNLOCK_GUARD_END(MmuLock);
+		MmuLock::Unlock();
+		RamAllocLock::Unlock();
+		return KErrBadDescriptor;
+		}
+
+	// Find physical address of the page, the breakpoint belongs to
+	TPhysAddr physAddr = Mmu::LinearToPhysical(aAddress, osAsid);
+	__KTRACE_OPT(KDEBUGGER,Kern::Printf("CodeModifier::SafeWriteCode - PA:%x", physAddr));
+
+
+	if (physAddr==KPhysAddrInvalid)
+		{
+		__KTRACE_OPT(KDEBUGGER,Kern::Printf("CodeModifier::SafeWriteCode - invalid VA"));
+		__UNLOCK_GUARD_END(MmuLock);
+		MmuLock::Unlock();
+		RamAllocLock::Unlock();
+		// The os asid is no longer required.
+		((DMemModelProcess*)aProcess)->CloseOsAsid();
+		return KErrBadDescriptor;
+		}
+
+	// Temporary map physical page
+	TLinAddr tempAddr = m.MapTemp(physAddr&~KPageMask, aAddress>>KPageShift);
+	tempAddr |=  aAddress & KPageMask;
+	__KTRACE_OPT(KDEBUGGER,Kern::Printf("CodeModifier::SafeWriteCode - tempAddr:%x",tempAddr));
+
+	TInt r = KErrBadDescriptor;
+	TUint32* ptr = (TUint32*)(tempAddr&~3);
+	TUint32 oldWord;
+
+	if(Kern::SafeRead(ptr,&oldWord,sizeof(oldWord))==0 // safely read the original value...
+		&& Kern::SafeWrite(ptr,&oldWord,sizeof(oldWord))==0 ) // and write it back
+		{
+		// We have successfully probed the memory by reading and writing to it
+		// so we assume it is now safe to access without generating exceptions.
+		// If this is wrong it will kill the system horribly.
+
+		TUint32 newWord;
+		TUint badAlign;
+		TUint shift = (aAddress&3)*8;
+
+		switch(aSize)
+			{
+		case 1: // 1 byte value
+			badAlign = 0;
+			*(TUint8*)aOldValue = oldWord>>shift;
+			newWord = (oldWord&~(0xff<<shift)) | ((aValue&0xff)<<shift);
+			break;
+
+		case 2: // 2 byte value
+			badAlign = tempAddr&1;
+			if(!badAlign)
+				*(TUint16*)aOldValue = oldWord>>shift;
+			newWord = (oldWord&~(0xffff<<shift)) | ((aValue&0xffff)<<shift);
+			break;
+
+		default: // 4 byte value
+			badAlign = tempAddr&3;
+			if(!badAlign)
+				*(TUint32*)aOldValue = oldWord;
+			newWord = aValue;
+			break;
+			}
+
+		if(!badAlign)
+			{
+			// write the new value...
+#ifdef __SMP__
+			TCodeModifierBroadcast b(ptr, newWord);
+			b.Go();
+#else
+			DoWriteCode(ptr, newWord);
+#endif
+			r = KErrNone;
+			}
+		}
+
+	__UNLOCK_GUARD_END(MmuLock);
+	m.UnmapTemp();
+	MmuLock::Unlock();
+	RamAllocLock::Unlock();
+	// The os asid is no longer required.
+	((DMemModelProcess*)aProcess)->CloseOsAsid();
+	return r;
+	}
+
+/**
+@pre Calling thread must be in critical section
+@pre CodeSeg mutex held
+*/
+void DoWriteCode(TUint32* aAddress, TUint32 aValue)
+	{
+	// We do not want to be interrupted by e.g. ISR that will run altered code before IMB-Range.
+	// Therefore, copy data and clean/invalidate caches with interrupts disabled.
+	TInt irq = NKern::DisableAllInterrupts();
+	*aAddress = aValue;
+	CacheMaintenance::CodeChanged((TLinAddr)aAddress, sizeof(TUint32), CacheMaintenance::ECodeModifier);
+	NKern::RestoreInterrupts(irq);
+	}
+
+#endif //__DEBUGGER_SUPPORT__
+
+
+
+//
+// Virtual pinning
+//
+
+TInt M::CreateVirtualPinObject(TVirtualPinObject*& aPinObject)
+	{
+	aPinObject = (TVirtualPinObject*)new DVirtualPinMapping;
+	return aPinObject != NULL ? KErrNone : KErrNoMemory;
+	}
+
+TInt M::PinVirtualMemory(TVirtualPinObject* aPinObject, TLinAddr aStart, TUint aSize, DThread* aThread)
+	{
+	NKern::ThreadEnterCS();
+	TUint offsetInMapping;
+	TUint mapInstanceCount;
+	DMemoryMapping* mapping = MM::FindMappingInThread(	(DMemModelThread*)aThread, 
+														aStart, 
+														aSize, 
+														offsetInMapping, 
+														mapInstanceCount);
+	TInt r = KErrBadDescriptor;
+	if (mapping)
+		{
+		TInt count = ((aStart & KPageMask) + aSize + KPageMask) >> KPageShift;
+		if(mapping->IsPinned())
+			{
+			// Mapping for specified virtual address is pinned so we don't need to
+			// do anything. Also, we can't safely pin the memory in this case
+			// anyway, as pinned mappings may move between memory objects
+			r = KErrNone;
+			}
+		else
+			{
+			MmuLock::Lock();
+			DMemoryObject* memory = mapping->Memory();
+			if (mapInstanceCount != mapping->MapInstanceCount() || 
+				!memory || !memory->IsDemandPaged())
+				{
+				// mapping has been reused, no memory, or it's not paged, so no need to pin...
+				MmuLock::Unlock();
+				r = KErrNone;
+				}
+			else
+				{
+				// paged memory needs pinning...
+				// Open a reference on the memory so it doesn't get deleted.
+				memory->Open();
+				MmuLock::Unlock();
+
+				TUint startInMemory = (offsetInMapping >> KPageShift) + mapping->iStartIndex;
+				r = ((DVirtualPinMapping*)aPinObject)->Pin(	memory, startInMemory, count, mapping->Permissions(),
+															mapping, mapInstanceCount);
+				memory->Close();
+				}
+			}
+		mapping->Close();
+		}
+	NKern::ThreadLeaveCS();
+	
+	return r;
+	}
+
+TInt M::CreateAndPinVirtualMemory(TVirtualPinObject*& aPinObject, TLinAddr aStart, TUint aSize)
+	{
+	aPinObject = 0;
+	NKern::ThreadEnterCS();
+	TUint offsetInMapping;
+	TUint mapInstanceCount;
+	DMemoryMapping* mapping = MM::FindMappingInThread(	(DMemModelThread*)&Kern::CurrentThread(), 
+														aStart, 
+														aSize, 
+														offsetInMapping,
+														mapInstanceCount);
+	TInt r = KErrBadDescriptor;
+	if (mapping)
+		{
+		TInt count = ((aStart & KPageMask) + aSize + KPageMask) >> KPageShift;
+		if(mapping->IsPinned())
+			{
+			// Mapping for specified virtual address is pinned so we don't need to
+			// do anything. Also, we can't safely pin the memory in this case
+			// anyway, as pinned mappings may move between memory objects
+			r = KErrNone;
+			}
+		else
+			{
+			MmuLock::Lock();
+			DMemoryObject* memory = mapping->Memory();
+			if (mapInstanceCount != mapping->MapInstanceCount() || 
+				!memory || !memory->IsDemandPaged())
+				{
+				// mapping has been reused, no memory, or it's not paged, so no need to pin...
+				MmuLock::Unlock();
+				r = KErrNone;
+				}
+			else
+				{// The memory is demand paged so create a pin object and pin it.
+				// Open a reference on the memory so it doesn't get deleted.
+				memory->Open();
+				MmuLock::Unlock();
+				r = CreateVirtualPinObject(aPinObject);
+				if (r == KErrNone)
+					{
+					TUint startInMemory = (offsetInMapping >> KPageShift) + mapping->iStartIndex;
+					r = ((DVirtualPinMapping*)aPinObject)->Pin(	memory, startInMemory, count, mapping->Permissions(), 
+																mapping, mapInstanceCount);
+					if (r != KErrNone)
+						{// Failed to pin the memory so pin object is not required.
+						DestroyVirtualPinObject(aPinObject);
+						}
+					}
+				memory->Close();
+				}
+			}
+		mapping->Close();
+		}
+	NKern::ThreadLeaveCS();
+	
+	return r;
+	}
+
+void M::UnpinVirtualMemory(TVirtualPinObject* aPinObject)
+	{
+	DVirtualPinMapping* mapping = (DVirtualPinMapping*)aPinObject;
+	if (mapping->IsAttached())
+		mapping->Unpin();
+	}
+	
+void M::DestroyVirtualPinObject(TVirtualPinObject*& aPinObject)
+	{
+	DVirtualPinMapping* mapping = (DVirtualPinMapping*)__e32_atomic_swp_ord_ptr(&aPinObject, 0);
+	if (mapping)
+		{
+		if (mapping->IsAttached())
+			mapping->Unpin();
+		mapping->AsyncClose();
+		}
+	}
+
+TInt M::CreatePhysicalPinObject(TPhysicalPinObject*& aPinObject)
+	{
+	aPinObject = (TPhysicalPinObject*)new DPhysicalPinMapping;
+	return aPinObject != NULL ? KErrNone : KErrNoMemory;
+	}
+
+//
+// Physical pinning
+//
+
+TInt M::PinPhysicalMemory(TPhysicalPinObject* aPinObject, TLinAddr aStart, TUint aSize, TBool aReadOnly,
+				TPhysAddr& aAddress, TPhysAddr* aPages, TUint32& aMapAttr, TUint& aColour, DThread* aThread)
+	{
+	NKern::ThreadEnterCS();
+	TUint offsetInMapping;
+	TUint mapInstanceCount;
+	DMemoryMapping* mapping = MM::FindMappingInThread(	(DMemModelThread*)aThread, 
+														aStart, 
+														aSize, 
+														offsetInMapping, 
+														mapInstanceCount);
+	TInt r = KErrBadDescriptor;
+	if (mapping)
+		{
+		TInt count = ((aStart & KPageMask) + aSize + KPageMask) >> KPageShift;
+
+		MmuLock::Lock();
+		DMemoryObject* memory = mapping->Memory();
+		if (mapInstanceCount == mapping->MapInstanceCount() && memory)
+			{
+			memory->Open();
+			MmuLock::Unlock();
+
+			TUint startInMemory = (offsetInMapping >> KPageShift) + mapping->iStartIndex;
+			TMappingPermissions permissions = aReadOnly ? ESupervisorReadOnly : ESupervisorReadWrite;
+			r = ((DPhysicalPinMapping*)aPinObject)->Pin(memory, startInMemory, count, permissions);
+			if (r == KErrNone)
+				{
+				r = ((DPhysicalPinMapping*)aPinObject)->PhysAddr(0, count, aAddress, aPages);
+				if (r>=KErrNone)
+					{
+					r = KErrNone; //Do not report discontiguous memory in return value.
+					const TMappingAttributes2& mapAttr2 =
+											MM::LegacyMappingAttributes(memory->Attributes(), mapping->Permissions());
+					*(TMappingAttributes2*)&aMapAttr = mapAttr2;
+					}
+				else
+					UnpinPhysicalMemory(aPinObject);
+				}
+			memory->Close();
+			}
+		else // mapping has been reused or no memory...
+			{
+			MmuLock::Unlock();
+			}
+		mapping->Close();
+		}
+	NKern::ThreadLeaveCS();
+	aColour = (aStart >>KPageShift) & KPageColourMask;
+	return r;
+	}
+
+void M::UnpinPhysicalMemory(TPhysicalPinObject* aPinObject)
+	{
+	DPhysicalPinMapping* mapping = (DPhysicalPinMapping*)aPinObject;
+	if (mapping->IsAttached())
+		mapping->Unpin();
+	}
+
+void M::DestroyPhysicalPinObject(TPhysicalPinObject*& aPinObject)
+	{
+	DPhysicalPinMapping* mapping = (DPhysicalPinMapping*)__e32_atomic_swp_ord_ptr(&aPinObject, 0);
+	if (mapping)
+		{
+		if (mapping->IsAttached())
+			mapping->Unpin();
+		mapping->AsyncClose();
+		}
+	}
+
+
+
+//
+// Cache sync operations
+//
+
+//@pre	As for MASK_THREAD_STANDARD
+void Mmu::SyncPhysicalMemoryBeforeDmaWrite(TPhysAddr* aPages, TUint aColour, TUint aOffset, TUint aSize, TUint32 aMapAttr)
+	{
+	//Jump over the pages we do not have to sync
+	aPages += aOffset>>KPageShift;
+	aOffset &=KPageMask;
+	aColour  = (aColour + (aOffset>>KPageShift)) & KPageColourMask;
+
+	//Calculate page table entry for the temporary mapping.
+	TUint pteType = PteType(ESupervisorReadWrite,true);
+	TMappingAttributes2 mapAttr2(aMapAttr);
+	TPte pte = Mmu::BlankPte((TMemoryAttributes)mapAttr2.Type(), pteType);
+	
+	while (aSize) //A single pass of loop operates within page boundaries.
+		{
+		TUint sizeInLoopPass = Min (KPageSize, aOffset+aSize) - aOffset; //The size of the region in this pass.
+
+		NKern::ThreadEnterCS();
+		Kern::MutexWait(*iPhysMemSyncMutex);
+		
+		TLinAddr linAddr = iPhysMemSyncTemp.Map(*aPages, aColour, pte);
+		CacheMaintenance::MakeCPUChangesVisible(linAddr+aOffset, sizeInLoopPass, aMapAttr, *aPages+aOffset);
+		iPhysMemSyncTemp.Unmap();
+		
+		Kern::MutexSignal(*iPhysMemSyncMutex);
+		NKern::ThreadLeaveCS();
+
+		aSize-=sizeInLoopPass;  // Remaining bytes to sync
+		aOffset=0;				// In all the pages after the first, sync will always start with zero offset.
+		aPages++;	// Point to the next page
+		aColour  = (aColour+1) & KPageColourMask;
+		}
+	}
+
+//@pre	As for MASK_THREAD_STANDARD
+void Mmu::SyncPhysicalMemoryBeforeDmaRead(TPhysAddr* aPages, TUint aColour, TUint aOffset, TUint aSize, TUint32 aMapAttr)
+	{
+	//Jump over the pages we do not have to sync
+	aPages += aOffset>>KPageShift;
+	aOffset &=KPageMask;
+	aColour  = (aColour + (aOffset>>KPageShift)) & KPageColourMask;
+
+	//Calculate page table entry for the temporary mapping.
+	TUint pteType = PteType(ESupervisorReadWrite,true);
+	TMappingAttributes2 mapAttr2(aMapAttr);
+	TPte pte = Mmu::BlankPte((TMemoryAttributes)mapAttr2.Type(), pteType);
+	
+	while (aSize) //A single pass of loop operates within page boundaries.
+		{
+		TUint sizeInLoopPass = Min (KPageSize, aOffset+aSize) - aOffset; //The size of the region in this pass.
+
+		NKern::ThreadEnterCS();
+		Kern::MutexWait(*iPhysMemSyncMutex);
+		
+		TLinAddr linAddr = iPhysMemSyncTemp.Map(*aPages, aColour, pte);
+		CacheMaintenance::PrepareMemoryForExternalWrites(linAddr+aOffset, sizeInLoopPass, aMapAttr, *aPages+aOffset);
+		iPhysMemSyncTemp.Unmap();
+		
+		Kern::MutexSignal(*iPhysMemSyncMutex);
+		NKern::ThreadLeaveCS();
+
+		aSize-=sizeInLoopPass;  // Remaining bytes to sync
+		aOffset=0;				// In all the pages after the first, sync will always start with zero offset.
+		aPages++;	// Point to the next page
+		aColour  = (aColour+1) & KPageColourMask;
+		}
+	}
+
+//@pre	As for MASK_THREAD_STANDARD
+void Mmu::SyncPhysicalMemoryAfterDmaRead(TPhysAddr* aPages, TUint aColour, TUint aOffset, TUint aSize, TUint32 aMapAttr)
+	{
+	//Jump over the pages we do not have to sync
+	aPages += aOffset>>KPageShift;
+	aOffset &=KPageMask;
+	aColour  = (aColour + (aOffset>>KPageShift)) & KPageColourMask;
+
+	//Calculate page table entry for the temporary mapping.
+	TUint pteType = PteType(ESupervisorReadWrite,true);
+	TMappingAttributes2 mapAttr2(aMapAttr);
+	TPte pte = Mmu::BlankPte((TMemoryAttributes)mapAttr2.Type(), pteType);
+	
+	while (aSize) //A single pass of loop operates within page boundaries.
+		{
+		TUint sizeInLoopPass = Min (KPageSize, aOffset+aSize) - aOffset; //The size of the region in this pass.
+
+		NKern::ThreadEnterCS();
+		Kern::MutexWait(*iPhysMemSyncMutex);
+		
+		TLinAddr linAddr = iPhysMemSyncTemp.Map(*aPages, aColour, pte);
+		CacheMaintenance::MakeExternalChangesVisible(linAddr+aOffset, sizeInLoopPass, aMapAttr, *aPages+aOffset);
+		iPhysMemSyncTemp.Unmap();
+		
+		Kern::MutexSignal(*iPhysMemSyncMutex);
+		NKern::ThreadLeaveCS();
+
+		aSize-=sizeInLoopPass;  // Remaining bytes to sync
+		aOffset=0;				// In all the pages after the first, sync will always start with zero offset.
+		aPages++;	// Point to the next page
+		aColour  = (aColour+1) & KPageColourMask;
+		}
+	}
+
+EXPORT_C TInt Cache::SyncPhysicalMemoryBeforeDmaWrite(TPhysAddr* aPages, TUint aColour, TUint aOffset, TUint aSize, TUint32 aMapAttr)
+	{
+	CHECK_PRECONDITIONS(MASK_THREAD_STANDARD,"Cache::SyncPhysicalMemoryBeforeDmaWrite");
+	TheMmu.SyncPhysicalMemoryBeforeDmaWrite(aPages, aColour, aOffset, aSize, aMapAttr);
+	return KErrNone;
+	}
+
+EXPORT_C TInt Cache::SyncPhysicalMemoryBeforeDmaRead(TPhysAddr* aPages, TUint aColour, TUint aOffset, TUint aSize, TUint32 aMapAttr)
+	{
+	CHECK_PRECONDITIONS(MASK_THREAD_STANDARD,"Cache::SyncPhysicalMemoryBeforeDmaRead");
+	TheMmu.SyncPhysicalMemoryBeforeDmaRead(aPages, aColour, aOffset, aSize, aMapAttr);
+	return KErrNone;
+	}
+
+EXPORT_C TInt Cache::SyncPhysicalMemoryAfterDmaRead(TPhysAddr* aPages, TUint aColour, TUint aOffset, TUint aSize, TUint32 aMapAttr)
+	{
+	CHECK_PRECONDITIONS(MASK_THREAD_STANDARD,"Cache::SyncPhysicalMemoryAfterDmaRead");
+	TheMmu.SyncPhysicalMemoryAfterDmaRead(aPages, aColour, aOffset, aSize, aMapAttr);
+	return KErrNone;
+	}