--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/baseport/syborg/soundsc/virtio.cpp	Thu Mar 04 00:55:21 2010 +0000
@@ -0,0 +1,58 @@
+/*
+* 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:
+* Accenture Ltd
+*
+* Contributors:
+*
+* Description: This file is a part of sound driver for Syborg adaptation.
+*
+*/
+
+#include "virtio.h"
+
+namespace VirtIo 
+{
+
+#define MIN(x,y) (((x)<=(y))?(x):(y))
+#define INVALID_PHYSADDR(x) ((x)==TPhysAddr(-1))
+
+TInt LinearToSGL( TAny* aVirtual, TUint aSize, TAddrLen aSGL[], TUint& aSGLCount )
+	{
+	const TUint pageSize = Kern::RoundToPageSize(1);
+	TUint8* virtAddr = reinterpret_cast<TUint8*>( aVirtual );
+	TPhysAddr physAddr = Epoc::LinearToPhysical( TLinAddr(virtAddr) );
+	if (INVALID_PHYSADDR(physAddr))
+		{ return KErrArgument; }
+	TUint sglLimit = aSGLCount;
+	aSGLCount = 0;
+	TUint left = aSize;
+	while (left)
+		{
+		TPhysAddr startPhysAddr = physAddr;
+		TUint8* startVirtAddr = virtAddr;
+		while ( (left) 
+			&& ( Epoc::LinearToPhysical( TLinAddr(virtAddr) ) == physAddr ) )
+			{
+			TUint size = MIN(left, pageSize);
+			physAddr += size;
+			virtAddr += size;
+			left -= size;
+			}
+		if (INVALID_PHYSADDR(physAddr))
+			{ return KErrArgument; }
+		if ((aSGL) && (aSGLCount<sglLimit))
+			{
+			aSGL[aSGLCount].iAddr = (TUint32) startPhysAddr;
+			aSGL[aSGLCount].iLen = virtAddr - startVirtAddr;
+			}
+		aSGLCount++;
+		}
+	return (aSGLCount<=sglLimit)?KErrNone:KErrNoMemory;
+	}
+	
+} // namespace VirtIo