diff -r d3e8e7d462dd -r f92a4f87e424 usbdrv/peripheral/pdd/pil/src/descriptors.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/usbdrv/peripheral/pdd/pil/src/descriptors.cpp	Tue Aug 31 17:01:47 2010 +0300
@@ -0,0 +1,2362 @@
+// Copyright (c) 2000-2009 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/drivers/usbcc/descriptors.cpp
+// Platform independent layer (PIL) of the USB Device controller driver:
+// USB descriptor handling and management.
+// 
+//
+
+/**
+ @file descriptors.cpp
+ @internalTechnology
+*/
+
+#include <kernel/kern_priv.h>
+// #include <drivers/usbc.h>
+#include <usb/usbc.h>
+
+
+// Debug Support
+static const char KUsbPanicCat[] = "USB PIL";
+
+
+// --- TUsbcDescriptorBase
+
+TUsbcDescriptorBase::TUsbcDescriptorBase()
+    :
+#ifdef USB_SUPPORTS_SET_DESCRIPTOR_REQUEST
+    iIndex(0),
+#endif
+    iBufPtr(NULL, 0)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorBase::TUsbcDescriptorBase()"));
+    }
+
+
+TUsbcDescriptorBase::~TUsbcDescriptorBase()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorBase::~TUsbcDescriptorBase()"));
+    }
+
+
+void TUsbcDescriptorBase::SetByte(TInt aPosition, TUint8 aValue)
+    {
+    iBufPtr[aPosition] = aValue;
+    }
+
+
+void TUsbcDescriptorBase::SetWord(TInt aPosition, TUint16 aValue)
+    {
+    *reinterpret_cast<TUint16*>(&iBufPtr[aPosition]) = SWAP_BYTES_16(aValue);
+    }
+
+
+TUint8 TUsbcDescriptorBase::Byte(TInt aPosition) const
+    {
+    return iBufPtr[aPosition];
+    }
+
+
+TUint16 TUsbcDescriptorBase::Word(TInt aPosition) const
+    {
+    return SWAP_BYTES_16(*reinterpret_cast<const TUint16*>(&iBufPtr[aPosition]));
+    }
+
+
+void TUsbcDescriptorBase::GetDescriptorData(TDes8& aBuffer) const
+    {
+    aBuffer = iBufPtr;
+    }
+
+
+TInt TUsbcDescriptorBase::GetDescriptorData(TUint8* aBuffer) const
+    {
+    memcpy(aBuffer, iBufPtr.Ptr(), Size());
+    return Size();
+    }
+
+
+TInt TUsbcDescriptorBase::GetDescriptorData(TUint8* aBuffer, TUint aMaxSize) const
+    {
+    if (aMaxSize < Size())
+        {
+        // No use to copy only half a descriptor
+        return 0;
+        }
+    return GetDescriptorData(aBuffer);
+    }
+
+
+const TDes8& TUsbcDescriptorBase::DescriptorData() const
+    {
+    return iBufPtr;
+    }
+
+
+TDes8& TUsbcDescriptorBase::DescriptorData()
+    {
+    return iBufPtr;
+    }
+
+
+TUint TUsbcDescriptorBase::Size() const
+    {
+    return iBufPtr.Size();
+    }
+
+
+TUint8 TUsbcDescriptorBase::Type() const
+    {
+    return iBufPtr[1];
+    }
+
+
+void TUsbcDescriptorBase::UpdateFs()
+    {
+    // virtual function can be overridden in derived classes.
+    return;
+    }
+
+
+void TUsbcDescriptorBase::UpdateHs()
+    {
+    // virtual function can be overridden in derived classes.
+    return;
+    }
+
+
+void TUsbcDescriptorBase::SetBufferPointer(const TDesC8& aDes)
+    {
+    iBufPtr.Set(const_cast<TUint8*>(aDes.Ptr()), aDes.Size(), aDes.Size());
+    }
+
+
+// --- TUsbcDeviceDescriptor
+
+TUsbcDeviceDescriptor::TUsbcDeviceDescriptor()
+    : iBuf()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceDescriptor::TUsbcDeviceDescriptor()"));
+    }
+
+
+TUsbcDeviceDescriptor* TUsbcDeviceDescriptor::New(TUint8 aDeviceClass, TUint8 aDeviceSubClass,
+                                                  TUint8 aDeviceProtocol, TUint8 aMaxPacketSize0,
+                                                  TUint16 aVendorId, TUint16 aProductId,
+                                                  TUint16 aDeviceRelease, TUint8 aNumConfigurations)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceDescriptor::New()"));
+    TUsbcDeviceDescriptor* self = new TUsbcDeviceDescriptor();
+    if (self)
+        {
+        if (self->Construct(aDeviceClass, aDeviceSubClass, aDeviceProtocol, aMaxPacketSize0, aVendorId,
+                            aProductId, aDeviceRelease, aNumConfigurations) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcDeviceDescriptor::Construct(TUint8 aDeviceClass, TUint8 aDeviceSubClass, TUint8 aDeviceProtocol,
+                                      TUint8 aMaxPacketSize0, TUint16 aVendorId, TUint16 aProductId,
+                                      TUint16 aDeviceRelease, TUint8 aNumConfigurations)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceDescriptor::Construct()"));
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBuf[0] = iBuf.Size();                                    // bLength
+    iBuf[1] = KUsbDescType_Device;                            // bDescriptorType
+    SetWord(2, KUsbcUsbVersion);                            // bcdUSB
+    iBuf[4] = aDeviceClass;                                    // bDeviceClass
+    iBuf[5] = aDeviceSubClass;                                // bDeviceSubClass
+    iBuf[6] = aDeviceProtocol;                                // bDeviceProtocol
+    iBuf[7] = aMaxPacketSize0;                                // bMaxPacketSize0
+    SetWord(8, aVendorId);                                    // idVendor
+    SetWord(10, aProductId);                                // idProduct
+    SetWord(12, aDeviceRelease);                            // bcdDevice
+    iBuf[14] = 0;                                            // iManufacturer
+    iBuf[15] = 0;                                            // iProduct
+    iBuf[16] = 0;                                            // iSerialNumber
+    iBuf[17] = aNumConfigurations;                            // bNumConfigurations
+    iEp0Size_Fs = aMaxPacketSize0;
+    return KErrNone;
+    }
+
+
+void TUsbcDeviceDescriptor::UpdateFs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceDescriptor::UpdateFs()"));
+    SetByte(7, iEp0Size_Fs);                                // bMaxPacketSize0
+    }
+
+
+void TUsbcDeviceDescriptor::UpdateHs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceDescriptor::UpdateHs()"));
+    SetByte(7, 64);                                            // bMaxPacketSize0
+    }
+
+
+// --- TUsbcDeviceQualifierDescriptor
+
+TUsbcDeviceQualifierDescriptor::TUsbcDeviceQualifierDescriptor()
+    : iBuf()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceDescriptor::TUsbcDeviceQualifierDescriptor()"));
+    }
+
+
+TUsbcDeviceQualifierDescriptor* TUsbcDeviceQualifierDescriptor::New(TUint8 aDeviceClass,
+                                                                    TUint8 aDeviceSubClass,
+                                                                    TUint8 aDeviceProtocol,
+                                                                    TUint8 aMaxPacketSize0,
+                                                                    TUint8 aNumConfigurations,
+                                                                    TUint8 aReserved)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceQualifierDescriptor::New()"));
+    TUsbcDeviceQualifierDescriptor* self = new TUsbcDeviceQualifierDescriptor();
+    if (self)
+        {
+        if (self->Construct(aDeviceClass, aDeviceSubClass, aDeviceProtocol, aMaxPacketSize0,
+                            aNumConfigurations, aReserved) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcDeviceQualifierDescriptor::Construct(TUint8 aDeviceClass, TUint8 aDeviceSubClass,
+                                               TUint8 aDeviceProtocol, TUint8 aMaxPacketSize0,
+                                               TUint8 aNumConfigurations, TUint8 aReserved)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceQualifierDescriptor::Construct()"));
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBuf[0] = iBuf.Size();                                    // bLength
+    iBuf[1] = KUsbDescType_DeviceQualifier;                    // bDescriptorType
+    SetWord(2, KUsbcUsbVersion);                            // bcdUSB
+    iBuf[4] = aDeviceClass;                                    // bDeviceClass
+    iBuf[5] = aDeviceSubClass;                                // bDeviceSubClass
+    iBuf[6] = aDeviceProtocol;                                // bDeviceProtocol
+    iBuf[7] = aMaxPacketSize0;                                // bMaxPacketSize0
+    iBuf[8] = aNumConfigurations;                            // bNumConfigurations
+    if (aReserved) aReserved = 0;
+    iBuf[9] = aReserved;                                    // Reserved for future use, must be zero
+    iEp0Size_Fs = aMaxPacketSize0;
+    return KErrNone;
+    }
+
+
+void TUsbcDeviceQualifierDescriptor::UpdateFs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceQualifierDescriptor::UpdateFs()"));
+    // Here we do exactly the opposite of what's done in the Device descriptor (as this one's
+    // documenting the 'other than the current speed').
+    SetByte(7, 64);                                            // bMaxPacketSize0
+    }
+
+
+void TUsbcDeviceQualifierDescriptor::UpdateHs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDeviceQualifierDescriptor::UpdateHs()"));
+    // Here we do exactly the opposite of what's done in the Device descriptor (as this one's
+    // documenting the 'other than the current speed').
+    SetByte(7, iEp0Size_Fs);                                // bMaxPacketSize0
+    }
+
+
+// --- TUsbcConfigDescriptor
+
+TUsbcConfigDescriptor::TUsbcConfigDescriptor()
+    : iBuf()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcConfigDescriptor::TUsbcConfigDescriptor()"));
+    }
+
+
+TUsbcConfigDescriptor* TUsbcConfigDescriptor::New(TUint8 aConfigurationValue, TBool aSelfPowered,
+                                                  TBool aRemoteWakeup, TUint16 aMaxPower)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcConfigDescriptor::New()"));
+    TUsbcConfigDescriptor* self = new TUsbcConfigDescriptor();
+    if (self)
+        {
+        if (self->Construct(aConfigurationValue, aSelfPowered, aRemoteWakeup, aMaxPower) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcConfigDescriptor::Construct(TUint8 aConfigurationValue, TBool aSelfPowered,
+                                       TBool aRemoteWakeup, TUint16 aMaxPower)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcConfigDescriptor::Construct()"));
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBuf[0] = iBuf.Size();                                    // bLength
+    iBuf[1] = KUsbDescType_Config;                            // bDescriptorType
+    SetWord(2, KUsbDescSize_Config);                        // wTotalLength
+    iBuf[4] = 0;                                            // bNumInterfaces
+    iBuf[5] = aConfigurationValue;                            // bConfigurationValue
+    iBuf[6] = 0;                                            // iConfiguration
+    iBuf[7] = 0x80 |
+        (aSelfPowered ? KUsbDevAttr_SelfPowered : 0) |
+        (aRemoteWakeup ? KUsbDevAttr_RemoteWakeup : 0);        // bmAttributes (bit 7 always 1)
+    if (aMaxPower > 510)
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Invalid value for bMaxPower: %d", aMaxPower));
+    iBuf[8] = aMaxPower / 2;                                // bMaxPower (2mA units!)
+    return KErrNone;
+    }
+
+
+// --- TUsbcInterfaceDescriptor
+
+TUsbcInterfaceDescriptor::TUsbcInterfaceDescriptor()
+    : iBuf()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcInterfaceDescriptor::TUsbcInterfaceDescriptor()"));
+    }
+
+
+TUsbcInterfaceDescriptor* TUsbcInterfaceDescriptor::New(TUint8 aInterfaceNumber, TUint8 aAlternateSetting,
+                                                        TInt aNumEndpoints, const TUsbcClassInfo& aClassInfo)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcInterfaceDescriptor::New()"));
+    TUsbcInterfaceDescriptor* self = new TUsbcInterfaceDescriptor();
+    if (self)
+        {
+        if (self->Construct(aInterfaceNumber, aAlternateSetting, aNumEndpoints, aClassInfo) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcInterfaceDescriptor::Construct(TUint8 aInterfaceNumber, TUint8 aAlternateSetting,
+                                         TInt aNumEndpoints, const TUsbcClassInfo& aClassInfo)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcInterfaceDescriptor::Construct()"));
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBuf[0] = iBuf.Size();                                    // bLength
+    iBuf[1] = KUsbDescType_Interface;                        // bDescriptorType
+    iBuf[2] = aInterfaceNumber;                                // bInterfaceNumber
+    iBuf[3] = aAlternateSetting;                            // bAlternateSetting
+    iBuf[4] = aNumEndpoints;                                // bNumEndpoints
+    iBuf[5] = aClassInfo.iClassNum;                            // bInterfaceClass
+    iBuf[6] = aClassInfo.iSubClassNum;                        // bInterfaceSubClass
+    iBuf[7] = aClassInfo.iProtocolNum;                        // bInterfaceProtocol
+    iBuf[8] = 0;                                            // iInterface
+    return KErrNone;
+    }
+
+
+// --- TUsbcEndpointDescriptorBase
+
+TUsbcEndpointDescriptorBase::TUsbcEndpointDescriptorBase()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcEndpointDescriptorBase::TUsbcEndpointDescriptorBase()"));
+    }
+
+
+TInt TUsbcEndpointDescriptorBase::Construct(const TUsbcEndpointInfo& aEpInfo)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcEndpointDescriptorBase::Construct()"));
+    //  Adjust FS/HS endpoint sizes
+    if (aEpInfo.AdjustEpSizes(iEpSize_Fs, iEpSize_Hs) != KErrNone)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Unknown endpoint type: %d", aEpInfo.iType));
+        }
+    __KTRACE_OPT(KUSB, Kern::Printf("  Now set: iEpSize_Fs=%d iEpSize_Hs=%d (aEpInfo.iSize=%d)",
+                                    iEpSize_Fs, iEpSize_Hs, aEpInfo.iSize));
+
+    //  Adjust HS endpoint size for additional transactions
+    if ((aEpInfo.iType == UsbShai::KUsbEpTypeIsochronous) || (aEpInfo.iType == UsbShai::KUsbEpTypeInterrupt))
+        {
+        if ((aEpInfo.iTransactions > 0) && (aEpInfo.iTransactions < 3))
+            {
+            // Bits 12..11 specify the number of additional transactions per microframe
+            iEpSize_Hs |= (aEpInfo.iTransactions << 12);
+            __KTRACE_OPT(KUSB, Kern::Printf("  Adjusted for add. transact.: iEpSize_Hs=0x%02x "
+                                            "(aEpInfo.iTransactions=%d)",
+                                            iEpSize_Hs, aEpInfo.iTransactions));
+            }
+        else if (aEpInfo.iTransactions != 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: Invalid iTransactions value: %d (ignored)",
+                                              aEpInfo.iTransactions));
+            }
+        }
+
+    //  Adjust HS polling interval
+    TUsbcEndpointInfo info(aEpInfo);                        // create local writeable copy
+    if (info.AdjustPollInterval() != KErrNone)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Unknown ep type (%d) or invalid interval value (%d)",
+                                          info.iType, info.iInterval));
+        }
+    iInterval_Fs = info.iInterval;
+    iInterval_Hs = info.iInterval_Hs;
+    __KTRACE_OPT(KUSB, Kern::Printf("  Now set: iInterval_Fs=%d iInterval_Hs=%d",
+                                    iInterval_Fs, iInterval_Hs));
+    return KErrNone;
+    }
+
+
+void TUsbcEndpointDescriptorBase::UpdateFs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcEndpointDescriptorBase::UpdateFs()"));
+    // (TUsbcEndpointDescriptorBase's FS/HS endpoint sizes and interval values got
+    //  adjusted in its Construct() method.)
+    SetWord(4, iEpSize_Fs);                                    // wMaxPacketSize
+    SetByte(6, iInterval_Fs);                                // bInterval
+    }
+
+
+void TUsbcEndpointDescriptorBase::UpdateHs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcEndpointDescriptorBase::UpdateHs()"));
+    // (TUsbcEndpointDescriptorBase's FS/HS endpoint sizes and interval values get
+    //  adjusted in its Construct() method.)
+    SetWord(4, iEpSize_Hs);                                    // wMaxPacketSize
+    SetByte(6, iInterval_Hs);                                // bInterval
+    }
+
+
+// --- TUsbcEndpointDescriptor
+
+TUsbcEndpointDescriptor::TUsbcEndpointDescriptor()
+    : iBuf()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcEndpointDescriptor::TUsbcEndpointDescriptor()"));
+    }
+
+
+TUsbcEndpointDescriptor* TUsbcEndpointDescriptor::New(TUint8 aEndpointAddress,
+                                                      const TUsbcEndpointInfo& aEpInfo)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcEndpointDescriptor::New()"));
+    TUsbcEndpointDescriptor* self = new TUsbcEndpointDescriptor();
+    if (self)
+        {
+        if (self->Construct(aEndpointAddress, aEpInfo) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcEndpointDescriptor::Construct(TUint8 aEndpointAddress, const TUsbcEndpointInfo& aEpInfo)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcEndpointDescriptor::Construct()"));
+    (void) TUsbcEndpointDescriptorBase::Construct(aEpInfo);    // Init Base class
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBuf[0] = iBuf.Size();                                    // bLength
+    iBuf[1] = KUsbDescType_Endpoint;                        // bDescriptorType
+    iBuf[2] = aEndpointAddress;                                // bEndpointAddress
+    iBuf[3] = EpTypeMask2Value(aEpInfo.iType);                // bmAttributes
+    SetWord(4, iEpSize_Fs);                                    // wMaxPacketSize (default is FS)
+    iBuf[6] = iInterval_Fs;                                    // bInterval (default is FS)
+    return KErrNone;
+    }
+
+
+// --- TUsbcAudioEndpointDescriptor
+
+TUsbcAudioEndpointDescriptor::TUsbcAudioEndpointDescriptor()
+    : iBuf()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcAudioEndpointDescriptor::TUsbcAudioEndpointDescriptor()"));
+    }
+
+
+TUsbcAudioEndpointDescriptor* TUsbcAudioEndpointDescriptor::New(TUint8 aEndpointAddress,
+                                                                const TUsbcEndpointInfo& aEpInfo)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcAudioEndpointDescriptor::New()"));
+    TUsbcAudioEndpointDescriptor* self = new TUsbcAudioEndpointDescriptor();
+    if (self)
+        {
+        if (self->Construct(aEndpointAddress, aEpInfo) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcAudioEndpointDescriptor::Construct(TUint8 aEndpointAddress, const TUsbcEndpointInfo& aEpInfo)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcAudioEndpointDescriptor::Construct()"));
+    (void) TUsbcEndpointDescriptorBase::Construct(aEpInfo);    // Init Base class
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBuf[0] = iBuf.Size();                                    // bLength
+    iBuf[1] = KUsbDescType_Endpoint;                        // bDescriptorType
+    iBuf[2] = aEndpointAddress;                                // bEndpointAddress
+    iBuf[3] = EpTypeMask2Value(aEpInfo.iType);                // bmAttributes
+    SetWord(4, iEpSize_Fs);                                    // wMaxPacketSize (default is FS)
+    iBuf[6] = iInterval_Fs;                                    // bInterval (default is FS)
+    iBuf[7] = 0;
+    iBuf[8] = 0;
+    return KErrNone;
+    }
+
+
+// --- TUsbcOtgDescriptor
+
+TUsbcOtgDescriptor* TUsbcOtgDescriptor::New(TBool aHnpSupport, TBool aSrpSupport)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcOtgDescriptor::New()"));
+    TUsbcOtgDescriptor* self = new TUsbcOtgDescriptor();
+    if (self && (self->Construct(aHnpSupport, aSrpSupport) != KErrNone))
+        {
+        delete self;
+        return NULL;
+        }
+    return self;
+    }
+
+
+TUsbcOtgDescriptor::TUsbcOtgDescriptor()
+    : iBuf()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcOtgDescriptor::TUsbcOtgDescriptor()"));
+    }
+
+
+TInt TUsbcOtgDescriptor::Construct(TBool aHnpSupport, TBool aSrpSupport)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcOtgDescriptor::Construct()"));
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBuf[0] = iBuf.Size();                                    // bLength
+    iBuf[1] = KUsbDescType_Otg;                                // bDescriptorType
+    iBuf[2] = (aHnpSupport ? KUsbOtgAttr_HnpSupp : 0) |
+        (aSrpSupport ? KUsbOtgAttr_SrpSupp : 0);            // bmAttributes
+    return KErrNone;
+    }
+
+
+// --- TUsbcClassSpecificDescriptor
+
+TUsbcClassSpecificDescriptor::TUsbcClassSpecificDescriptor()
+    : iBuf(NULL)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcClassSpecificDescriptor::TUsbcClassSpecificDescriptor()"));
+    }
+
+
+TUsbcClassSpecificDescriptor::~TUsbcClassSpecificDescriptor()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcClassSpecificDescriptor::~TUsbcClassSpecificDescriptor()"));
+    delete iBuf;
+    }
+
+
+TUsbcClassSpecificDescriptor* TUsbcClassSpecificDescriptor::New(TUint8 aType, TInt aSize)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcClassSpecificDescriptor::New()"));
+    TUsbcClassSpecificDescriptor* self = new TUsbcClassSpecificDescriptor();
+    if (self)
+        {
+        if (self->Construct(aType, aSize) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcClassSpecificDescriptor::Construct(TUint8 aType, TInt aSize)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcClassSpecificDescriptor::Construct()"));
+    iBuf = HBuf8::New(aSize);
+    if (!iBuf)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Allocation of CS desc buffer failed"));
+        return KErrNoMemory;
+        }
+    iBuf->SetMax();
+    SetBufferPointer(*iBuf);
+    SetByte(1, aType);                                        // bDescriptorType
+    return KErrNone;
+    }
+
+
+// --- TUsbcStringDescriptorBase
+
+TUsbcStringDescriptorBase::TUsbcStringDescriptorBase()
+    : /*iIndex(0),*/ iSBuf(0), iBufPtr(NULL, 0)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcStringDescriptorBase::TUsbcStringDescriptorBase()"));
+    }
+
+
+TUsbcStringDescriptorBase::~TUsbcStringDescriptorBase()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcStringDescriptorBase::~TUsbcStringDescriptorBase()"));
+    }
+
+
+TUint16 TUsbcStringDescriptorBase::Word(TInt aPosition) const
+    {
+    if (aPosition <= 1)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Word(%d) in string descriptor "
+                                          "(TUsbcStringDescriptorBase::Word)", aPosition));
+        return 0;
+        }
+    else
+        {
+        // since iBufPtr[0] is actually string descriptor byte index 2,
+        // we have to subtract 2 from the absolute position.
+        return SWAP_BYTES_16(*reinterpret_cast<const TUint16*>(&iBufPtr[aPosition - 2]));
+        }
+    }
+
+
+void TUsbcStringDescriptorBase::SetWord(TInt aPosition, TUint16 aValue)
+    {
+    if (aPosition <= 1)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: SetWord(%d) in string descriptor "
+                                          "(TUsbcStringDescriptorBase::SetWord)", aPosition));
+        return;
+        }
+    else
+        {
+        // since iBufPtr[0] is actually string descriptor byte index 2,
+        // we have to subtract 2 from the absolute position.
+        *reinterpret_cast<TUint16*>(&iBufPtr[aPosition - 2]) = SWAP_BYTES_16(aValue);
+        }
+    }
+
+
+TInt TUsbcStringDescriptorBase::GetDescriptorData(TUint8* aBuffer) const
+    {
+    aBuffer[0] = iSBuf[0];
+    aBuffer[1] = iSBuf[1];
+    memcpy(&aBuffer[2], iBufPtr.Ptr(), iBufPtr.Size());
+    return Size();
+    }
+
+
+TInt TUsbcStringDescriptorBase::GetDescriptorData(TUint8* aBuffer, TUint aMaxSize) const
+    {
+    if (aMaxSize < Size())
+        {
+        // No use to copy only half a string
+        return 0;
+        }
+    return GetDescriptorData(aBuffer);
+    }
+
+
+const TDes8& TUsbcStringDescriptorBase::StringData() const
+    {
+    return iBufPtr;
+    }
+
+
+TDes8& TUsbcStringDescriptorBase::StringData()
+    {
+    return iBufPtr;
+    }
+
+
+TUint TUsbcStringDescriptorBase::Size() const
+    {
+    return iSBuf[0];
+    }
+
+
+void TUsbcStringDescriptorBase::SetBufferPointer(const TDesC8& aDes)
+    {
+    iBufPtr.Set(const_cast<TUint8*>(aDes.Ptr()), aDes.Size(), aDes.Size());
+    }
+
+
+// --- TUsbcStringDescriptor
+
+TUsbcStringDescriptor::TUsbcStringDescriptor()
+    : iBuf(NULL)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcStringDescriptor::TUsbcStringDescriptor()"));
+    }
+
+
+TUsbcStringDescriptor::~TUsbcStringDescriptor()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcStringDescriptor::~TUsbcStringDescriptor()"));
+    delete iBuf;
+    }
+
+
+TUsbcStringDescriptor* TUsbcStringDescriptor::New(const TDesC8& aString)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcStringDescriptor::New"));
+    TUsbcStringDescriptor* self = new TUsbcStringDescriptor();
+    if (self)
+        {
+        if (self->Construct(aString) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcStringDescriptor::Construct(const TDesC8& aString)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcStringDescriptor::Construct"));
+    iBuf = HBuf8::New(aString.Size());                        // bytes, not UNICODE chars
+    if (!iBuf)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Allocation of string buffer failed"));
+        return KErrNoMemory;
+        }
+    iBuf->SetMax();
+    SetBufferPointer(*iBuf);
+    iBufPtr.Copy(aString);
+    iSBuf.SetMax();
+    iSBuf[0] = iBuf->Size() + 2;                            // Bytes
+    iSBuf[1] = KUsbDescType_String;
+    return KErrNone;
+    }
+
+
+// --- TUsbcLangIdDescriptor
+
+TUsbcLangIdDescriptor::TUsbcLangIdDescriptor()
+    : iBuf(NULL)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcLangIdDescriptor::TUsbcLangIdDescriptor()"));
+    }
+
+
+TUsbcLangIdDescriptor::~TUsbcLangIdDescriptor()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcLangIdDescriptor::~TUsbcLangIdDescriptor()"));
+    }
+
+
+TUsbcLangIdDescriptor* TUsbcLangIdDescriptor::New(TUint16 aLangId)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcLangIdDescriptor::New"));
+    TUsbcLangIdDescriptor* self = new TUsbcLangIdDescriptor();
+    if (self)
+        {
+        if (self->Construct(aLangId) != KErrNone)
+            {
+            delete self;
+            return NULL;
+            }
+        }
+    return self;
+    }
+
+
+TInt TUsbcLangIdDescriptor::Construct(TUint16 aLangId)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcLangIdDescriptor::Construct"));
+    iBuf.SetMax();
+    SetBufferPointer(iBuf);
+    iBufPtr[0] = LowByte(SWAP_BYTES_16(aLangId));            // Language ID value
+    iBufPtr[1] = HighByte(SWAP_BYTES_16(aLangId));
+    iSBuf.SetMax();
+    iSBuf[0] = iBuf.Size() + 2;                                // Bytes
+    iSBuf[1] = KUsbDescType_String;
+    return KErrNone;
+    }
+
+
+// --- TUsbcDescriptorPool
+
+TUsbcDescriptorPool::TUsbcDescriptorPool(TUint8* aEp0_TxBuf)
+//
+//    The constructor for this class.
+//
+    : iDescriptors(), iStrings(), iIfcIdx(0), iEp0_TxBuf(aEp0_TxBuf), iHighSpeed(EFalse)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::TUsbcDescriptorPool()"));
+    }
+
+
+TUsbcDescriptorPool::~TUsbcDescriptorPool()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::~TUsbcDescriptorPool()"));
+    // The destructor of each <class T> object is called before the objects themselves are destroyed.
+    __KTRACE_OPT(KUSB, Kern::Printf("  iDescriptors.Count(): %d", iDescriptors.Count()));
+    iDescriptors.ResetAndDestroy();
+    __KTRACE_OPT(KUSB, Kern::Printf("  iStrings.Count(): %d", iStrings.Count()));
+    iStrings.ResetAndDestroy();
+    }
+
+
+TInt TUsbcDescriptorPool::Init(TUsbcDeviceDescriptor* aDeviceDesc, TUsbcConfigDescriptor* aConfigDesc,
+                               TUsbcLangIdDescriptor* aLangId, TUsbcStringDescriptor* aManufacturer,
+                               TUsbcStringDescriptor* aProduct, TUsbcStringDescriptor* aSerialNum,
+                               TUsbcStringDescriptor* aConfig, TUsbcOtgDescriptor* aOtgDesc)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::Init()"));
+    if (!aDeviceDesc || !aConfigDesc)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: No Device or Config descriptor specified"));
+        return KErrArgument;
+        }
+    for (TInt n = 0; n < KDescPosition_FirstAvailable; n++)
+        {
+        iDescriptors.Append(NULL);
+        }
+    __ASSERT_DEBUG((iDescriptors.Count() == KDescPosition_FirstAvailable),
+                   Kern::Printf("  Error: iDescriptors.Count() (%d) != KDescPosition_FirstAvailable (%d)",
+                                iDescriptors.Count(), KDescPosition_FirstAvailable));
+    iDescriptors[KDescPosition_Device] = aDeviceDesc;
+    iDescriptors[KDescPosition_Config] = aConfigDesc;
+    if (aOtgDesc)
+        {
+        iDescriptors[KDescPosition_Otg] = aOtgDesc;
+        // Update the config descriptor's wTotalLength field
+        UpdateConfigDescriptorLength(KUsbDescSize_Otg);
+        }
+    if (!aLangId)
+        {
+        // USB spec 9.6.7 says: "String index zero for all languages returns a string descriptor
+        // that contains an array of two-byte LANGID codes supported by the device. ...
+        // USB devices that omit all string descriptors must not return an array of LANGID codes."
+        // So if we have at least one string descriptor, we must also have a LANGID descriptor.
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: No LANGID string descriptor specified"));
+        return KErrArgument;
+        }
+    iStrings.Insert(aLangId, KStringPosition_Langid);
+    iStrings.Insert(aManufacturer, KStringPosition_Manufact);
+    iStrings.Insert(aProduct, KStringPosition_Product);
+    iStrings.Insert(aSerialNum, KStringPosition_Serial);
+    iStrings.Insert(aConfig, KStringPosition_Config);
+    __ASSERT_DEBUG((iStrings.Count() == 5),
+                   Kern::Printf("  Error: iStrings.Count() != 5 (%d)", iStrings.Count()));
+#ifdef _DEBUG
+    for (TInt i = KStringPosition_Langid; i <= KStringPosition_Config; i++)
+        {
+        __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool.iStrings[%d] = 0x%x", i, iStrings[i]));
+        }
+#endif
+    // Set string indices
+    if (aManufacturer)
+        iDescriptors[KDescPosition_Device]->SetByte(KUsbDescStringIndex_Manufact,
+                                                    KStringPosition_Manufact);
+    if (aProduct)
+        iDescriptors[KDescPosition_Device]->SetByte(KUsbDescStringIndex_Product,
+                                                    KStringPosition_Product);
+    if (aSerialNum)
+        iDescriptors[KDescPosition_Device]->SetByte(KUsbDescStringIndex_Serial,
+                                                    KStringPosition_Serial);
+    if (aConfig)
+        iDescriptors[KDescPosition_Config]->SetByte(KUsbDescStringIndex_Config,
+                                                    KStringPosition_Config);
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::InitHs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::InitHs()"));
+    __ASSERT_DEBUG((iDescriptors.Count() >= KDescPosition_FirstAvailable),
+                   Kern::Printf("  Error: Call Init() first)"));
+
+    TUsbcDeviceQualifierDescriptor* const dq_desc = TUsbcDeviceQualifierDescriptor::New(
+        iDescriptors[KDescPosition_Device]->Byte(4),        // aDeviceClass
+        iDescriptors[KDescPosition_Device]->Byte(5),        // aDeviceSubClass
+        iDescriptors[KDescPosition_Device]->Byte(6),        // aDeviceProtocol
+        iDescriptors[KDescPosition_Device]->Byte(7),        // aMaxPacketSize0
+        iDescriptors[KDescPosition_Device]->Byte(17));        // aNumConfigurations
+    if (!dq_desc)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Memory allocation for dev qualif desc failed."));
+        return KErrGeneral;
+        }
+    iDescriptors[KDescPosition_DeviceQualifier] = dq_desc;
+
+    TUsbcOtherSpeedConfigDescriptor* const osc_desc = TUsbcOtherSpeedConfigDescriptor::New(
+        iDescriptors[KDescPosition_Config]->Byte(5),        // aConfigurationValue
+        iDescriptors[KDescPosition_Config]->Byte(7) & KUsbDevAttr_SelfPowered, // aSelfPowered
+        iDescriptors[KDescPosition_Config]->Byte(7) & KUsbDevAttr_RemoteWakeup,    // aRemoteWakeup
+        iDescriptors[KDescPosition_Config]->Byte(8) * 2);    // aMaxPower (mA)
+    if (!osc_desc)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Memory allocation for other speed conf desc failed."));
+        return KErrGeneral;
+        }
+
+    // We need to set the bDescriptorType field manually, as that's the only one
+    // that differs from a Configuration descriptor.
+    osc_desc->SetByte(1, KUsbDescType_OtherSpeedConfig);
+
+    // Also, initially we set the iConfiguration string index to the same value as
+    // in the Configuration descriptor.
+    osc_desc->SetByte(KUsbDescStringIndex_Config,
+                      iDescriptors[KDescPosition_Config]->Byte(KUsbDescStringIndex_Config));
+
+    iDescriptors[KDescPosition_OtherSpeedConfig] = osc_desc;
+
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::UpdateDescriptorsFs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::UpdateDescriptorsFs()"));
+    const TInt count = iDescriptors.Count();
+    for (TInt i = KDescPosition_FirstAvailable; i < count; i++)
+        {
+        TUsbcDescriptorBase* const ptr = iDescriptors[i];
+        ptr->UpdateFs();
+        }
+    iHighSpeed = EFalse;
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::UpdateDescriptorsHs()
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::UpdateDescriptorsHs()"));
+    const TInt count = iDescriptors.Count();
+    for (TInt i = KDescPosition_FirstAvailable; i < count; i++)
+        {
+        TUsbcDescriptorBase* const ptr = iDescriptors[i];
+        ptr->UpdateHs();
+        }
+    iHighSpeed = ETrue;
+    return KErrNone;
+    }
+
+
+//
+// An error can be indicated by either a return value != KErrNone or by a descriptor size == 0.
+//
+TInt TUsbcDescriptorPool::FindDescriptor(TUint8 aType, TUint8 aIndex, TUint16 aLangid, TInt& aSize) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::FindDescriptor()"));
+    TInt result = KErrGeneral;
+    switch (aType)
+        {
+    case KUsbDescType_Device:
+        if (aLangid != 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad langid: 0x%04x", aLangid));
+            }
+        else if (aIndex > 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad device index: %d", aIndex));
+            }
+        else
+            {
+            aSize = GetDeviceDescriptor(KDescPosition_Device);
+            result = KErrNone;
+            }
+        break;
+    case KUsbDescType_Config:
+        if (aLangid != 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad langid: 0x%04x", aLangid));
+            }
+        else if (aIndex > 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad config index: %d", aIndex));
+            }
+        else
+            {
+            aSize = GetConfigurationDescriptor(KDescPosition_Config);
+            result = KErrNone;
+            }
+        break;
+    case KUsbDescType_DeviceQualifier:
+        if (aLangid != 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad langid: 0x%04x", aLangid));
+            }
+        else if (aIndex > 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad device index: %d", aIndex));
+            }
+        else
+            {
+            aSize = GetDeviceDescriptor(KDescPosition_DeviceQualifier);
+            result = KErrNone;
+            }
+        break;
+    case KUsbDescType_OtherSpeedConfig:
+        if (aLangid != 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad langid: 0x%04x", aLangid));
+            }
+        else if (aIndex > 0)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bad config index: %d", aIndex));
+            }
+        else
+            {
+            aSize = GetConfigurationDescriptor(KDescPosition_OtherSpeedConfig);
+            result = KErrNone;
+            }
+        break;
+    case KUsbDescType_Otg:
+        aSize = GetOtgDescriptor();
+        result = KErrNone;
+        break;
+    case KUsbDescType_String:
+        if (aIndex == 0)                                    // 0 addresses the LangId array
+            {
+            if (AnyStringDescriptors())
+                {
+                aSize = GetStringDescriptor(aIndex);
+                result = KErrNone;
+                }
+            else
+                {
+                __KTRACE_OPT(KUSB, Kern::Printf("  No string descriptors: not returning LANGID array"));
+                }
+            }
+        else
+            {
+               if (!aLangid)
+                   {
+                   __KTRACE_OPT(KUSB,
+                              Kern::Printf("  Strange: LANGID=0 for a $ descriptor (ignoring LANGID)"));
+                // The USB spec doesn't really say what to do in this case, but as there are host apps
+                // that fail if we return an error here, we choose to ignore the issue.
+                   }
+            else if (aLangid != iStrings[KStringPosition_Langid]->Word(2))
+                {
+                // We have only one (this) language
+                __KTRACE_OPT(KUSB,
+                             Kern::Printf("  Bad LANGID: 0x%04X requested, 0x%04X supported (ignoring LANGID)",
+                                          aLangid, iStrings[KStringPosition_Langid]->Word(2)));
+                // We could return an error here, but rather choose to ignore the discrepancy
+                // (the USB spec is not very clear what to do in such a case anyway).
+                }
+            aSize = GetStringDescriptor(aIndex);
+            result = KErrNone;
+            }
+        break;
+    case KUsbDescType_CS_Interface:
+        /* fall through */
+    case KUsbDescType_CS_Endpoint:
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: finding of class specific descriptors not supported"));
+        break;
+    default:
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: unknown descriptor type requested: %d", aType));
+        break;
+        }
+    return result;
+    }
+
+
+void TUsbcDescriptorPool::InsertDescriptor(TUsbcDescriptorBase* aDesc)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::InsertDescriptor()"));
+    switch (aDesc->Type())
+        {
+    case KUsbDescType_Interface:
+        InsertIfcDesc(aDesc);
+        break;
+    case KUsbDescType_Endpoint:
+        InsertEpDesc(aDesc);
+        break;
+    default:
+        __KTRACE_OPT(KUSB, Kern::Printf("  Error: unsupported descriptor type"));
+        }
+    }
+
+
+void TUsbcDescriptorPool::SetIfcStringDescriptor(TUsbcStringDescriptor* aDesc, TInt aNumber, TInt aSetting)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetIfcDescriptor(%d, %d)", aNumber, aSetting));
+    const TInt i = FindIfcDescriptor(aNumber, aSetting);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Ifc descriptor not found (%d, %d)",
+                                          aNumber, aSetting));
+        return;
+        }
+    // Try to find available NULL postition
+    TInt str_idx = FindAvailableStringPos();
+    if (str_idx >= 0)
+        {
+        // Insert string descriptor for specified interface
+        ExchangeStringDescriptor(str_idx, aDesc);
+        }
+    else
+        {
+        // No NULL found - expand array
+        str_idx = iStrings.Count();
+        if (str_idx > 0xff)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: $ descriptor array full (idx=%d)", str_idx));
+            return;
+            }
+        while (str_idx < KStringPosition_FirstAvailable)
+            {
+            iStrings.Append(NULL);
+            str_idx = iStrings.Count();
+            }
+        // Append string descriptor for specified interface
+        iStrings.Append(aDesc);
+        }
+    // Update this ifc descriptor's string index field
+    iDescriptors[i]->SetByte(8, str_idx);
+    __KTRACE_OPT(KUSB, Kern::Printf("  String for ifc %d/%d (@ pos %d): \"%S\"", aNumber, aSetting, str_idx,
+                                    &iStrings[str_idx]->StringData()));
+    }
+
+
+void TUsbcDescriptorPool::DeleteIfcDescriptor(TInt aNumber, TInt aSetting)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::DeleteIfcDescriptor(%d, %d)", aNumber, aSetting));
+    const TInt i = FindIfcDescriptor(aNumber, aSetting);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: DeleteIfcDescriptor - descriptor not found (%d, %d)",
+                                          aNumber, aSetting));
+        return;
+        }
+    // Delete (if necessary) specified interface's string descriptor
+    const TInt si = iDescriptors[i]->Byte(8);
+    if (si != 0)
+        {
+        ExchangeStringDescriptor(si, NULL);
+        }
+    // Delete specified ifc setting + all its cs descriptors + all its endpoints + all their cs descriptors:
+    // find position of the next interface descriptor: we need to delete everything in between
+    const TInt count = iDescriptors.Count();
+    TInt j = i, n = 1;
+    while (++j < count && iDescriptors[j]->Type() != KUsbDescType_Interface)
+        ++n;
+    DeleteDescriptors(i, n);
+    // Update all the following interfaces' bInterfaceNumber field if required
+    // (because those descriptors might have moved down by one position)
+    UpdateIfcNumbers(aNumber);
+    iIfcIdx = 0;                                            // ifc index no longer valid
+    }
+
+
+// The TC in many of the following functions stands for 'ThreadCopy',
+// because that's what's happening there.
+
+TInt TUsbcDescriptorPool::GetDeviceDescriptorTC(DThread* aThread, TDes8& aBuffer) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetDeviceDescriptorTC()"));
+    return Kern::ThreadDesWrite(aThread, &aBuffer, iDescriptors[KDescPosition_Device]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetDeviceDescriptorTC(DThread* aThread, const TDes8& aBuffer)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetDeviceDescriptorTC()"));
+    TBuf8<KUsbDescSize_Device> device;
+    const TInt r = Kern::ThreadDesRead(aThread, &aBuffer, device, 0);
+    if (r != KErrNone)
+        {
+        return r;
+        }
+    iDescriptors[KDescPosition_Device]->SetByte(2, device[2]); // bcdUSB
+    iDescriptors[KDescPosition_Device]->SetByte(3, device[3]); // bcdUSB (part II)
+    iDescriptors[KDescPosition_Device]->SetByte(4, device[4]); // bDeviceClass
+    iDescriptors[KDescPosition_Device]->SetByte(5, device[5]); // bDeviceSubClass
+    iDescriptors[KDescPosition_Device]->SetByte(6, device[6]); // bDeviceProtocol
+    iDescriptors[KDescPosition_Device]->SetByte(8, device[8]); // idVendor
+    iDescriptors[KDescPosition_Device]->SetByte(9, device[9]); // idVendor (part II)
+    iDescriptors[KDescPosition_Device]->SetByte(10, device[10]); // idProduct
+    iDescriptors[KDescPosition_Device]->SetByte(11, device[11]); // idProduct (part II)
+    iDescriptors[KDescPosition_Device]->SetByte(12, device[12]); // bcdDevice
+    iDescriptors[KDescPosition_Device]->SetByte(13, device[13]); // bcdDevice (part II)
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetConfigurationDescriptorTC(DThread* aThread, TDes8& aBuffer) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetConfigurationDescriptorTC()"));
+    return Kern::ThreadDesWrite(aThread, &aBuffer, iDescriptors[KDescPosition_Config]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetConfigurationDescriptorTC(DThread* aThread, const TDes8& aBuffer)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetConfigurationDescriptorTC()"));
+    TBuf8<KUsbDescSize_Config> config;
+    const TInt r = Kern::ThreadDesRead(aThread, &aBuffer, config, 0);
+    if (r != KErrNone)
+        {
+        return r;
+        }
+    iDescriptors[KDescPosition_Config]->SetByte(7, config[7]); // bmAttributes
+    iDescriptors[KDescPosition_Config]->SetByte(8, config[8]); // bMaxPower
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetOtgDescriptorTC(DThread* aThread, TDes8& aBuffer) const
+    {
+    return Kern::ThreadDesWrite(aThread, &aBuffer, iDescriptors[KDescPosition_Otg]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetOtgDescriptor(const TDesC8& aBuffer)
+    {
+    iDescriptors[KDescPosition_Otg]->SetByte(2, aBuffer[2]); // bmAttributes
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetInterfaceDescriptorTC(DThread* aThread, TDes8& aBuffer,
+                                                   TInt aInterface, TInt aSetting) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetInterfaceDescriptorTC()"));
+    const TInt i = FindIfcDescriptor(aInterface, aSetting);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such interface"));
+        return KErrNotFound;
+        }
+    return Kern::ThreadDesWrite(aThread, &aBuffer, iDescriptors[i]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetInterfaceDescriptor(const TDes8& aBuffer, TInt aInterface, TInt aSetting)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetInterfaceDescriptor()"));
+    const TInt i = FindIfcDescriptor(aInterface, aSetting);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such interface"));
+        return KErrNotFound;
+        }
+    iDescriptors[i]->SetByte(2, aBuffer[2]);                // bInterfaceNumber
+    iDescriptors[i]->SetByte(5, aBuffer[5]);                // bInterfaceClass
+    iDescriptors[i]->SetByte(6, aBuffer[6]);                // bInterfaceSubClass
+    iDescriptors[i]->SetByte(7, aBuffer[7]);                // bInterfaceProtocol
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetEndpointDescriptorTC(DThread* aThread, TDes8& aBuffer,
+                                                  TInt aInterface, TInt aSetting, TUint8 aEndpointAddress) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetEndpointDescriptorTC()"));
+    const TInt i = FindEpDescriptor(aInterface, aSetting, aEndpointAddress);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint"));
+        return KErrNotFound;
+        }
+    return Kern::ThreadDesWrite(aThread, &aBuffer, iDescriptors[i]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetEndpointDescriptorTC(DThread* aThread, const TDes8& aBuffer,
+                                                  TInt aInterface, TInt aSetting, TUint8 aEndpointAddress)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetEndpointDescriptorTC()"));
+    const TInt i = FindEpDescriptor(aInterface, aSetting, aEndpointAddress);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint"));
+        return KErrNotFound;
+        }
+    TBuf8<KUsbDescSize_AudioEndpoint> ep;                    // it could be an audio endpoint
+    const TInt r = Kern::ThreadDesRead(aThread, &aBuffer, ep, 0);
+    if (r != KErrNone)
+        {
+        return r;
+        }
+    iDescriptors[i]->SetByte(3, ep[3]);                        // bmAttributes
+    iDescriptors[i]->SetByte(6, ep[6]);                        // bInterval
+    if (iDescriptors[i]->Size() == KUsbDescSize_AudioEndpoint)
+        {
+        iDescriptors[i]->SetByte(7, ep[7]);                    // bRefresh
+        iDescriptors[i]->SetByte(8, ep[8]);                    // bSynchAddress
+        }
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetEndpointDescriptorSize(TInt aInterface, TInt aSetting, TUint8 aEndpointAddress,
+                                                    TInt& aSize) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetEndpointDescriptorSize()"));
+    const TInt i = FindEpDescriptor(aInterface, aSetting, aEndpointAddress);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint"));
+        return KErrNotFound;
+        }
+    aSize = iDescriptors[i]->Size();
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetDeviceQualifierDescriptorTC(DThread* aThread, TDes8& aBuffer) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetDeviceQualifierDescriptorTC()"));
+    if (iDescriptors[KDescPosition_DeviceQualifier] == NULL)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: Device_Qualifier descriptor not supported"));
+        return KErrNotSupported;
+        }
+    return Kern::ThreadDesWrite(aThread, &aBuffer,
+                                iDescriptors[KDescPosition_DeviceQualifier]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetDeviceQualifierDescriptorTC(DThread* aThread, const TDes8& aBuffer)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetDeviceQualifierDescriptorTC()"));
+    if (iDescriptors[KDescPosition_DeviceQualifier] == NULL)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: Device_Qualifier descriptor not supported"));
+        return KErrNotSupported;
+        }
+    TBuf8<KUsbDescSize_DeviceQualifier> device;
+    const TInt r = Kern::ThreadDesRead(aThread, &aBuffer, device, 0);
+    if (r != KErrNone)
+        {
+        return r;
+        }
+    iDescriptors[KDescPosition_DeviceQualifier]->SetByte(2, device[2]); // bcdUSB
+    iDescriptors[KDescPosition_DeviceQualifier]->SetByte(3, device[3]); // bcdUSB (part II)
+    iDescriptors[KDescPosition_DeviceQualifier]->SetByte(4, device[4]); // bDeviceClass
+    iDescriptors[KDescPosition_DeviceQualifier]->SetByte(5, device[5]); // bDeviceSubClass
+    iDescriptors[KDescPosition_DeviceQualifier]->SetByte(6, device[6]); // bDeviceProtocol
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetOtherSpeedConfigurationDescriptorTC(DThread* aThread, TDes8& aBuffer) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetOtherSpeedConfigurationDescriptorTC()"));
+    if (iDescriptors[KDescPosition_OtherSpeedConfig] == NULL)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: Other_Speed_Configuration descriptor not supported"));
+        return KErrNotSupported;
+        }
+    return Kern::ThreadDesWrite(aThread, &aBuffer,
+                                iDescriptors[KDescPosition_OtherSpeedConfig]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetOtherSpeedConfigurationDescriptorTC(DThread* aThread, const TDes8& aBuffer)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetOtherSpeedConfigurationDescriptorTC()"));
+    if (iDescriptors[KDescPosition_OtherSpeedConfig] == NULL)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: Other_Speed_Configuration descriptor not supported"));
+        return KErrNotSupported;
+        }
+    TBuf8<KUsbDescSize_OtherSpeedConfig> config;
+    const TInt r = Kern::ThreadDesRead(aThread, &aBuffer, config, 0);
+    if (r != KErrNone)
+        {
+        return r;
+        }
+    iDescriptors[KDescPosition_OtherSpeedConfig]->SetByte(7, config[7]); // bmAttributes
+    iDescriptors[KDescPosition_OtherSpeedConfig]->SetByte(8, config[8]); // bMaxPower
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetCSInterfaceDescriptorTC(DThread* aThread, TDes8& aBuffer,
+                                                     TInt aInterface, TInt aSetting) const
+    {
+    // first find the interface
+    TInt i = FindIfcDescriptor(aInterface, aSetting);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such interface"));
+        return KErrNotFound;
+        }
+    TInt r = KErrNotFound;
+    TInt offset = 0;
+    const TInt count = iDescriptors.Count();
+    while (++i < count && iDescriptors[i]->Type() == KUsbDescType_CS_Interface)
+        {
+        r = Kern::ThreadDesWrite(aThread, &aBuffer,
+                                 iDescriptors[i]->DescriptorData(), offset);
+        if (r != KErrNone)
+            break;
+        offset += iDescriptors[i]->Size();
+        }
+    return r;
+    }
+
+
+TInt TUsbcDescriptorPool::SetCSInterfaceDescriptorTC(DThread* aThread, const TDes8& aBuffer,
+                                                     TInt aInterface, TInt aSetting, TInt aSize)
+    {
+    // First find the interface
+    TInt i = FindIfcDescriptor(aInterface, aSetting);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such interface"));
+        return KErrNotFound;
+        }
+    // Find a position where to insert the new class specific interface descriptor(s)
+    const TInt count = iDescriptors.Count();
+    while (++i < count && iDescriptors[i]->Type() == KUsbDescType_CS_Interface)
+        ;
+    // Create a new cs descriptor
+    TUsbcClassSpecificDescriptor* desc = TUsbcClassSpecificDescriptor::New(KUsbDescType_CS_Interface, aSize);
+    if (!desc)
+        {
+        return KErrNoMemory;
+        }
+    __KTRACE_OPT(KUSB, Kern::Printf("  inserting descriptor at position %d", i));
+    iDescriptors.Insert(desc, i);
+
+    // Update the config descriptor's wTotalLength field
+    UpdateConfigDescriptorLength(aSize);
+
+    // Copy contents from the user side
+    return Kern::ThreadDesRead(aThread, &aBuffer, iDescriptors[i]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::GetCSInterfaceDescriptorSize(TInt aInterface, TInt aSetting, TInt& aSize) const
+    {
+    // first find the interface
+    TInt i = FindIfcDescriptor(aInterface, aSetting);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such interface"));
+        return KErrNotFound;
+        }
+    TInt r = KErrNotFound;
+    TInt size = 0;
+    const TInt count = iDescriptors.Count();
+    while (++i < count && iDescriptors[i]->Type() == KUsbDescType_CS_Interface)
+        {
+        size += iDescriptors[i]->Size();
+        r = KErrNone;
+        }
+    if (r == KErrNone)
+        aSize = size;
+    return r;
+    }
+
+
+TInt TUsbcDescriptorPool::GetCSEndpointDescriptorTC(DThread* aThread, TDes8& aBuffer, TInt aInterface,
+                                                    TInt aSetting, TUint8 aEndpointAddress) const
+    {
+    // first find the endpoint
+    TInt i = FindEpDescriptor(aInterface, aSetting, aEndpointAddress);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint"));
+        return KErrNotFound;
+        }
+    TInt r = KErrNotFound;
+    TInt offset = 0;
+    const TInt count = iDescriptors.Count();
+    while (++i < count && iDescriptors[i]->Type() == KUsbDescType_CS_Endpoint)
+        {
+        r = Kern::ThreadDesWrite(aThread, &aBuffer,
+                                 iDescriptors[i]->DescriptorData(), offset);
+        if (r != KErrNone)
+            break;
+        offset += iDescriptors[i]->Size();
+        }
+    return r;
+    }
+
+
+TInt TUsbcDescriptorPool::SetCSEndpointDescriptorTC(DThread* aThread, const TDes8& aBuffer, TInt aInterface,
+                                                    TInt aSetting, TUint8 aEndpointAddress, TInt aSize)
+    {
+    // first find the endpoint
+    TInt i = FindEpDescriptor(aInterface, aSetting, aEndpointAddress);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint"));
+        return KErrNotFound;
+        }
+    // find a position where to insert the new class specific endpoint descriptor(s)
+    const TInt count = iDescriptors.Count();
+    while (++i < count && iDescriptors[i]->Type() == KUsbDescType_CS_Endpoint)
+        ;
+    // create a new cs descriptor
+    TUsbcClassSpecificDescriptor* desc = TUsbcClassSpecificDescriptor::New(KUsbDescType_CS_Endpoint, aSize);
+    if (!desc)
+        {
+        return KErrNoMemory;
+        }
+    iDescriptors.Insert(desc, i);
+    // update the config descriptor's wTotalLength field
+    UpdateConfigDescriptorLength(aSize);
+    // copy contents from user side
+    return Kern::ThreadDesRead(aThread, &aBuffer, iDescriptors[i]->DescriptorData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::GetCSEndpointDescriptorSize(TInt aInterface, TInt aSetting,
+                                                      TUint8 aEndpointAddress, TInt& aSize) const
+    {
+    // first find the endpoint
+    TInt i = FindEpDescriptor(aInterface, aSetting, aEndpointAddress);
+    if (i < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint"));
+        return KErrNotFound;
+        }
+    TInt r = KErrNotFound;
+    TInt size = 0;
+    const TInt count = iDescriptors.Count();
+    while (++i < count && iDescriptors[i]->Type() == KUsbDescType_CS_Endpoint)
+        {
+        size += iDescriptors[i]->Size();
+        r = KErrNone;
+        }
+    if (r == KErrNone)
+        aSize = size;
+    return r;
+    }
+
+
+TInt TUsbcDescriptorPool::GetStringDescriptorLangIdTC(DThread* aThread, TDes8& aLangId) const
+    {
+    const TUint16 id = iStrings[KStringPosition_Langid]->Word(2);
+    const TPtrC8 id_des(reinterpret_cast<const TUint8*>(&id), sizeof(id));
+    return Kern::ThreadDesWrite(aThread, &aLangId, id_des, 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetStringDescriptorLangId(TUint16 aLangId)
+    {
+    iStrings[KStringPosition_Langid]->SetWord(2, aLangId);
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetManufacturerStringDescriptorTC(DThread* aThread, TDes8& aString) const
+    {
+    return GetDeviceStringDescriptorTC(aThread, aString, KUsbDescStringIndex_Manufact,
+                                       KStringPosition_Manufact);
+    }
+
+
+TInt TUsbcDescriptorPool::SetManufacturerStringDescriptorTC(DThread* aThread, const TDes8& aString)
+    {
+    return SetDeviceStringDescriptorTC(aThread, aString, KUsbDescStringIndex_Manufact,
+                                       KStringPosition_Manufact);
+    }
+
+
+TInt TUsbcDescriptorPool::RemoveManufacturerStringDescriptor()
+    {
+    return RemoveDeviceStringDescriptor(KUsbDescStringIndex_Manufact, KStringPosition_Manufact);
+    }
+
+
+TInt TUsbcDescriptorPool::GetProductStringDescriptorTC(DThread* aThread, TDes8& aString) const
+    {
+    return GetDeviceStringDescriptorTC(aThread, aString, KUsbDescStringIndex_Product,
+                                       KStringPosition_Product);
+    }
+
+
+TInt TUsbcDescriptorPool::SetProductStringDescriptorTC(DThread* aThread, const TDes8& aString)
+    {
+    return SetDeviceStringDescriptorTC(aThread, aString, KUsbDescStringIndex_Product,
+                                       KStringPosition_Product);
+    }
+
+
+TInt TUsbcDescriptorPool::RemoveProductStringDescriptor()
+    {
+    return RemoveDeviceStringDescriptor(KUsbDescStringIndex_Product, KStringPosition_Product);
+    }
+
+
+TInt TUsbcDescriptorPool::GetSerialNumberStringDescriptorTC(DThread* aThread, TDes8& aString) const
+    {
+    return GetDeviceStringDescriptorTC(aThread, aString, KUsbDescStringIndex_Serial,
+                                       KStringPosition_Serial);
+    }
+
+
+TInt TUsbcDescriptorPool::SetSerialNumberStringDescriptorTC(DThread* aThread, const TDes8& aString)
+    {
+    return SetDeviceStringDescriptorTC(aThread, aString, KUsbDescStringIndex_Serial,
+                                       KStringPosition_Serial);
+    }
+
+
+TInt TUsbcDescriptorPool::RemoveSerialNumberStringDescriptor()
+    {
+    return RemoveDeviceStringDescriptor(KUsbDescStringIndex_Serial, KStringPosition_Serial);
+    }
+
+
+TInt TUsbcDescriptorPool::GetConfigurationStringDescriptorTC(DThread* aThread, TDes8& aString) const
+    {
+    const TInt str_idx = iDescriptors[KDescPosition_Config]->Byte(KUsbDescStringIndex_Config);
+    if (str_idx)
+        {
+        __ASSERT_ALWAYS((str_idx == KStringPosition_Config), Kern::Fault(KUsbPanicCat, __LINE__));
+        __KTRACE_OPT(KUSB, Kern::Printf("  String @ pos %d (conf $): \"%S\"",
+                                        str_idx, &iStrings[str_idx]->StringData()));
+        return Kern::ThreadDesWrite(aThread, &aString,
+                                    iStrings[str_idx]->StringData(), 0);
+        }
+    else
+        {
+        __KTRACE_OPT(KUSB, Kern::Printf("  No config string descriptor @ pos %d", str_idx));
+        return KErrNotFound;
+        }
+    }
+
+
+TInt TUsbcDescriptorPool::SetConfigurationStringDescriptorTC(DThread* aThread, const TDes8& aString)
+    {
+    // we don't know the length of the string, so we have to allocate memory dynamically
+    TUint strlen = Kern::ThreadGetDesLength(aThread, &aString);
+    if (strlen > KUsbStringDescStringMaxSize)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: config $ descriptor too long - will be truncated"));
+        strlen = KUsbStringDescStringMaxSize;
+        }
+    HBuf8* const strbuf = HBuf8::New(strlen);
+    if (!strbuf)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Memory allocation for config $ desc string failed (1)"));
+        return KErrNoMemory;
+        }
+    strbuf->SetMax();
+    // the aString points to data that lives in user memory, so we have to copy it:
+    const TInt r = Kern::ThreadDesRead(aThread, &aString, *strbuf, 0);
+    if (r != KErrNone)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Thread read error"));
+        delete strbuf;
+        return r;
+        }
+    TUsbcStringDescriptor* sd = TUsbcStringDescriptor::New(*strbuf);
+    if (!sd)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Memory allocation for config $ desc failed (2)"));
+        delete strbuf;
+        return KErrNoMemory;
+        }
+    // Delete old string, put in new one
+    ExchangeStringDescriptor(KStringPosition_Config, sd);
+    // Update Config descriptor string index field
+    iDescriptors[KDescPosition_Config]->SetByte(KUsbDescStringIndex_Config, KStringPosition_Config);
+    // Update Other_Speed_Config descriptor string index field as well, if applicable
+    if (iDescriptors[KDescPosition_OtherSpeedConfig])
+        iDescriptors[KDescPosition_OtherSpeedConfig]->SetByte(KUsbDescStringIndex_Config,
+                                                              KStringPosition_Config);
+    delete strbuf;
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::RemoveConfigurationStringDescriptor()
+    {
+    if (iDescriptors[KDescPosition_Config]->Byte(KUsbDescStringIndex_Config) == 0)
+        {
+        __KTRACE_OPT(KUSB, Kern::Printf("  RemoveConfigurationStringDescriptor: no $ desc @ index %d",
+                                        KUsbDescStringIndex_Config));
+        return KErrNotFound;
+        }
+    // Delete old string, put in NULL pointer
+    ExchangeStringDescriptor(KStringPosition_Config, NULL);
+    // Update Config descriptor string index field
+    iDescriptors[KDescPosition_Config]->SetByte(KUsbDescStringIndex_Config, 0);
+    // Update Other_Speed_Config descriptor string index field as well, if applicable
+    if (iDescriptors[KDescPosition_OtherSpeedConfig])
+        iDescriptors[KDescPosition_OtherSpeedConfig]->SetByte(KUsbDescStringIndex_Config, 0);
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::GetStringDescriptorTC(DThread* aThread, TInt aIndex, TDes8& aString) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetStringDescriptorTC()"));
+    if (!StringDescriptorExists(aIndex))
+        {
+        return KErrNotFound;
+        }
+    __KTRACE_OPT(KUSB, Kern::Printf("  String @ pos %d: \"%S\"",
+                                    aIndex, &iStrings[aIndex]->StringData()));
+    return Kern::ThreadDesWrite(aThread, &aString, iStrings[aIndex]->StringData(), 0);
+    }
+
+
+TInt TUsbcDescriptorPool::SetStringDescriptorTC(DThread* aThread, TInt aIndex, const TDes8& aString)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetStringDescriptorTC()"));
+    // we don't know the length of the string, so we have to allocate memory dynamically
+    TUint strlen = Kern::ThreadGetDesLength(aThread, &aString);
+    if (strlen > KUsbStringDescStringMaxSize)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: $ descriptor too long - will be truncated"));
+        strlen = KUsbStringDescStringMaxSize;
+        }
+    HBuf8* strbuf = HBuf8::New(strlen);
+    if (!strbuf)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Mem alloc for $ desc string failed (1)"));
+        return KErrNoMemory;
+        }
+    strbuf->SetMax();
+    // the aString points to data that lives in user memory, so we have to copy it over:
+    const TInt r = Kern::ThreadDesRead(aThread, &aString, *strbuf, 0);
+    if (r != KErrNone)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Thread read error"));
+        delete strbuf;
+        return r;
+        }
+    TUsbcStringDescriptor* const sd = TUsbcStringDescriptor::New(*strbuf);
+    if (!sd)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Mem alloc for $ desc failed (2)"));
+        delete strbuf;
+        return KErrNoMemory;
+        }
+    if (aIndex < iStrings.Count())
+        {
+        ExchangeStringDescriptor(aIndex, sd);
+        }
+    else // if (aIndex >= iStrings.Count())
+        {
+        while (aIndex > iStrings.Count())
+            {
+            iStrings.Append(NULL);
+            }
+        iStrings.Append(sd);
+        }
+    delete strbuf;
+    return KErrNone;
+    }
+
+
+TInt TUsbcDescriptorPool::RemoveStringDescriptor(TInt aIndex)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::RemoveStringDescriptor()"));
+    if (!StringDescriptorExists(aIndex))
+        {
+        return KErrNotFound;
+        }
+    __KTRACE_OPT(KUSB, Kern::Printf("  Removing string @ pos %d: \"%S\"",
+                                    aIndex, &iStrings[aIndex]->StringData()));
+    ExchangeStringDescriptor(aIndex, NULL);
+
+    // Make sure there's no $ after aIndex.
+    const TInt n = iStrings.Count();
+    for (TInt i = aIndex; i < n; i++)
+        {
+        if (iStrings[i] != NULL)
+            {
+            __KTRACE_OPT(KUSB, Kern::Printf("  Found $ @ idx %d - not compressing", i));
+            return KErrNone;
+            }
+        }
+
+    __KTRACE_OPT(KUSB, Kern::Printf("  No $ found after idx %d - compressing array", aIndex));
+    // Move aIndex back just before the first !NULL element.
+    while (iStrings[--aIndex] == NULL)
+        ;
+    // Let aIndex point to first NULL.
+    aIndex++;
+    __KTRACE_OPT(KUSB, Kern::Printf("  Starting at index %d", aIndex));
+    // Now remove NULL pointers until (Count() == aIndex).
+    __KTRACE_OPT(KUSB, Kern::Printf("  iStrings.Count() before: %d", iStrings.Count()));
+    do
+        {
+        iStrings.Remove(aIndex);
+        __KTRACE_OPT(KUSB, Kern::Printf("  Removing $"));
+        }
+    while (iStrings.Count() > aIndex);
+    __KTRACE_OPT(KUSB, Kern::Printf("  iStrings.Count() after: %d", iStrings.Count()));
+
+    // Regain some memory.
+    iStrings.Compress();
+
+    return KErrNone;
+    }
+
+
+// ===================================================================
+// --- private ---
+// ===================================================================
+
+//
+// Insert an Interface descriptor into the descriptor array at the appropriate index.
+//
+void TUsbcDescriptorPool::InsertIfcDesc(TUsbcDescriptorBase* aDesc)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::InsertIfcDesc()"));
+
+    const TInt count = iDescriptors.Count();
+    TBool ifc_exists = EFalse;                                // set to 'true' if we're adding an alternate
+                                                            // setting to an already existing interface
+    TInt i = KDescPosition_FirstAvailable;
+    while (i < count)
+        {
+        __KTRACE_OPT(KUSB, Kern::Printf("  already descriptors there (%d)...", count));
+        if (iDescriptors[i]->Type() == KUsbDescType_Interface)
+            {
+            if (iDescriptors[i]->Byte(2) > aDesc->Byte(2))
+                {
+                // our interface number is less than the one's just found => insert before it (= here)
+                break;
+                }
+            else if (iDescriptors[i]->Byte(2) == aDesc->Byte(2))
+                {
+                ifc_exists = ETrue;
+                // same interface number => look at settings number
+                if (iDescriptors[i]->Byte(3) > aDesc->Byte(3))
+                    {
+                    // our setting number is less than the one's found => insert before (= here)
+                    break;
+                    }
+                else if (iDescriptors[i]->Byte(3) == aDesc->Byte(3))
+                    {
+                    __KTRACE_OPT(KPANIC, Kern::Printf("  Error: first delete old desc "
+                                                      "(TUsbcDescriptorPool::InsertIfcDesc)"));
+                    return;
+                    }
+                }
+            }
+        ++i;
+        }
+    // In any case: put the new descriptor at position i.
+    __KTRACE_OPT(KUSB, Kern::Printf("  inserting descriptor at position %d", i));
+    iDescriptors.Insert(aDesc, i);
+
+    // Update the config descriptor's wTotalLength field.
+    UpdateConfigDescriptorLength(KUsbDescSize_Interface);
+
+    if (!ifc_exists)
+        {
+        // If this is the first setting for the interface, increment bNumInterfaces.
+        UpdateConfigDescriptorNumIfcs(1);
+        }
+
+    iIfcIdx = i;
+    }
+
+
+//
+// Insert an Endpoint descriptor into the descriptor array at the appropriate index.
+//
+void TUsbcDescriptorPool::InsertEpDesc(TUsbcDescriptorBase* aDesc)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::InsertEpDesc()"));
+    if (iIfcIdx == 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: only after interface "
+                                          "(TUsbcDescriptorPool::InsertEpDesc)"));
+        return;
+        }
+    const TInt count = iDescriptors.Count();
+    TInt i = iIfcIdx + 1;
+    while (i < count)
+        {
+        if (iDescriptors[i]->Type() != KUsbDescType_Endpoint)
+            break;
+        ++i;
+        }
+    // put the new descriptor at position i
+    iDescriptors.Insert(aDesc, i);
+    // update the config descriptor's wTotalLength field
+    UpdateConfigDescriptorLength(aDesc->Size());
+    }
+
+
+//
+// Find the index of the Interface descriptor for a given interface setting.
+//
+TInt TUsbcDescriptorPool::FindIfcDescriptor(TInt aIfcNumber, TInt aIfcSetting) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::FindIfcDescriptor(%d, %d)",
+                                    aIfcNumber, aIfcSetting));
+    const TInt count = iDescriptors.Count();
+    for (TInt i = KDescPosition_FirstAvailable; i < count; i++)
+        {
+        if ((iDescriptors[i]->Type() == KUsbDescType_Interface) &&
+            (iDescriptors[i]->Byte(2) == aIfcNumber) &&
+            (iDescriptors[i]->Byte(3) == aIfcSetting))
+            {
+            return i;
+            }
+        }
+    __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such interface"));
+    return -1;
+    }
+
+
+//
+// Find the index of the Endpoint descriptor for a given endpoint on a given interface setting.
+//
+TInt TUsbcDescriptorPool::FindEpDescriptor(TInt aIfcNumber, TInt aIfcSetting, TUint8 aEpAddress) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::FindEpDescriptor(%d, %d, 0x%02x)",
+                                    aIfcNumber, aIfcSetting, aEpAddress));
+    // first find the interface
+    const TInt ifc = FindIfcDescriptor(aIfcNumber, aIfcSetting);
+    if (ifc < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such interface"));
+        return ifc;
+        }
+    const TInt count = iDescriptors.Count();
+    // then, before the next interface, try to locate the endpoint
+    for (TInt i = ifc + 1; i < count; i++)
+        {
+        if (iDescriptors[i]->Type() == KUsbDescType_Interface)
+            {
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint before next interface"));
+            return -1;
+            }
+        else if ((iDescriptors[i]->Type() == KUsbDescType_Endpoint) &&
+                 (iDescriptors[i]->Byte(2) == aEpAddress))
+            {
+            // found
+            return i;
+            }
+        }
+    __KTRACE_OPT(KPANIC, Kern::Printf("  Error: no such endpoint"));
+    return -1;
+    }
+
+
+//
+// Delete n descriptors starting from aIndex and remove their pointers from the array.
+//
+void TUsbcDescriptorPool::DeleteDescriptors(TInt aIndex, TInt aCount)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::DeleteDescriptors()"));
+    if (aIndex < KDescPosition_FirstAvailable)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: aIndex < KDescPosition_FirstAvailable"));
+        return;
+        }
+    if (aCount <= 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: aCount <= 0"));
+        return;
+        }
+    __KTRACE_OPT(KUSB, Kern::Printf("  Removing descriptors at index %d:", aIndex));
+    // Try to update wTotalLength field in Config descriptor
+    while (aCount--)
+        {
+        // In this loop we don't decrement aIndex, because after deleting an element
+        // aIndex is already indexing the next one.
+        TUsbcDescriptorBase* const ptr = iDescriptors[aIndex];
+        switch (ptr->Type())
+            {
+        case KUsbDescType_Interface:
+            __KTRACE_OPT(KUSB, Kern::Printf("  - an interface descriptor"));
+            UpdateConfigDescriptorLength(-KUsbDescSize_Interface);
+            break;
+        case KUsbDescType_Endpoint:
+            __KTRACE_OPT(KUSB, Kern::Printf("  - an endpoint descriptor"));
+            UpdateConfigDescriptorLength(-ptr->Size());
+            break;
+        case KUsbDescType_CS_Interface:
+            /* fall through */
+        case KUsbDescType_CS_Endpoint:
+            __KTRACE_OPT(KUSB, Kern::Printf("  - a class specific descriptor"));
+            UpdateConfigDescriptorLength(-ptr->Size());
+            break;
+        default:
+            __KTRACE_OPT(KUSB, Kern::Printf("  - an unknown descriptor"));
+            __KTRACE_OPT(KPANIC, Kern::Printf("  Error: unknown descriptor type"));
+            }
+        iDescriptors.Remove(aIndex);
+        delete ptr;
+        }
+    }
+
+
+//
+// Update the wTotalLength field in the Configuration descriptor (aLength can be negative).
+//
+void TUsbcDescriptorPool::UpdateConfigDescriptorLength(TInt aLength)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::UpdateConfigDescriptorLength(%d)", aLength));
+    TUsbcDescriptorBase* const cnf = iDescriptors[KDescPosition_Config];
+    __KTRACE_OPT(KUSB, Kern::Printf("  wTotalLength old: %d", cnf->Word(2)));
+    // Update Config descriptor
+    cnf->SetWord(2, cnf->Word(2) + aLength);
+    __KTRACE_OPT(KUSB, Kern::Printf("  wTotalLength new: %d", cnf->Word(2)));
+    // Update Other_Speed_Config descriptor as well, if applicable
+    if (iDescriptors[KDescPosition_OtherSpeedConfig])
+        iDescriptors[KDescPosition_OtherSpeedConfig]->SetWord(2, cnf->Word(2));
+    }
+
+
+//
+// Update the bNumInterfaces field in the Configuration descriptor (aNumber can be negative).
+//
+void TUsbcDescriptorPool::UpdateConfigDescriptorNumIfcs(TInt aNumber)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::UpdateConfigDescriptorNumIfcs(%d)", aNumber));
+    TUsbcDescriptorBase* const cnf = iDescriptors[KDescPosition_Config];
+    __KTRACE_OPT(KUSB, Kern::Printf("  bNumInterfaces old: %d", cnf->Byte(4)));
+    const TInt n = cnf->Byte(4) + aNumber;
+    if (n < 0)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: bNumInterfaces + aNumber < 0"));
+        return;
+        }
+    // Update Config descriptor
+    cnf->SetByte(4, n);
+    __KTRACE_OPT(KUSB, Kern::Printf("  bNumInterfaces new: %d", cnf->Byte(4)));
+    // Update Other_Speed_Config descriptor as well, if applicable
+    if (iDescriptors[KDescPosition_OtherSpeedConfig])
+        iDescriptors[KDescPosition_OtherSpeedConfig]->SetByte(4, n);
+    }
+
+
+//
+// Update the bNumInterfaces field in the Configuration descriptor if necessary.
+//
+void TUsbcDescriptorPool::UpdateIfcNumbers(TInt aNumber)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::UpdateIfcNumbers(%d)", aNumber));
+    const TInt count = iDescriptors.Count();
+    for (TInt i = KDescPosition_FirstAvailable; i < count; i++)
+        {
+        if ((iDescriptors[i]->Type() == KUsbDescType_Interface) &&
+            (iDescriptors[i]->Byte(2) == aNumber))
+            {
+            // there's still an interface with 'number' so we don't need to update anything
+            return;
+            }
+        }
+    // if we haven't returned yet, we decrement bNumInterfaces
+    UpdateConfigDescriptorNumIfcs(-1);
+    }
+
+
+//
+// Put the current Device or Device_Qualifier descriptor in the Ep0 Tx buffer.
+// Only used for Ep0 standard requests, so target buffer can be hard-wired.
+//
+TInt TUsbcDescriptorPool::GetDeviceDescriptor(TInt aIndex) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetDeviceDescriptor()"));
+    __ASSERT_DEBUG((aIndex == KDescPosition_Device) || (aIndex == KDescPosition_DeviceQualifier),
+                   Kern::Printf("  Error: invalid descriptor index: %d", aIndex));
+    if (iDescriptors[aIndex] == NULL)
+        {
+        // This doesn't have to be an error - we might get asked here for the Device_Qualifier descriptor
+        // on a FS-only device.
+        __KTRACE_OPT(KUSB, Kern::Printf("  Descriptor #%d requested but not available", aIndex));
+        return 0;
+        }
+    return iDescriptors[aIndex]->GetDescriptorData(iEp0_TxBuf, KUsbcBufSz_Ep0Tx);
+    }
+
+
+//
+// Put the current Configuration or Other_Speed_Configuration descriptor + all the following
+// descriptors in the Ep0 Tx buffer.
+// Only used for Ep0 standard requests, so target buffer can be hard-wired.
+//
+TInt TUsbcDescriptorPool::GetConfigurationDescriptor(TInt aIndex) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetConfigDescriptor(%d)", aIndex));
+    __ASSERT_DEBUG((aIndex == KDescPosition_Config) || (aIndex == KDescPosition_OtherSpeedConfig),
+                   Kern::Printf("  Error: invalid descriptor index: %d", aIndex));
+    if (iDescriptors[aIndex] == NULL)
+        {
+        // This is always an error: We should always have a Configuration descriptor and we should never
+        // get asked for the Other_Speed_Configuration descriptor if we don't have one (9.6.2).
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: Descriptor %d requested but not available", aIndex));
+        return 0;
+        }
+    const TInt count = iDescriptors.Count();
+    TInt copied = 0;
+    TUint8* buf = iEp0_TxBuf;
+    for (TInt i = aIndex; i < count; i++)
+        {
+        TUsbcDescriptorBase* const ptr = iDescriptors[i];
+        if ((aIndex == KDescPosition_OtherSpeedConfig) && (i == KDescPosition_Config))
+            {
+            // Skip Config descriptor when returning Other_Speed_Config
+            continue;
+            }
+        if ((i == KDescPosition_Otg) && (iDescriptors[i] == NULL))
+            {
+            __KTRACE_OPT(KUSB, Kern::Printf("  no OTG descriptor -> next"));
+            continue;
+            }
+        // We need to edit endpoint descriptors on the fly because we have only one copy
+        // of each and that copy has to contain different information, depending on the
+        // current speed and the type of descriptor requested.
+        if (ptr->Type() == KUsbDescType_Endpoint)
+            {
+            if ((iHighSpeed && (aIndex == KDescPosition_Config)) ||
+                (!iHighSpeed && (aIndex == KDescPosition_OtherSpeedConfig)))
+                {
+                ptr->UpdateHs();
+                }
+            else
+                {
+                ptr->UpdateFs();
+                }
+            }
+        __KTRACE_OPT(KUSB, Kern::Printf("  desc[%02d]: type = 0x%02x size = %d ",
+                                        i, ptr->Type(), ptr->Size()));
+        const TInt size = ptr->GetDescriptorData(buf, KUsbcBufSz_Ep0Tx - copied);
+        if (size == 0)
+            {
+            __KTRACE_OPT(KPANIC,
+                         Kern::Printf("  Error: No Tx buffer space to copy this descriptor -> exiting"));
+            break;
+            }
+        copied += size;
+        if (copied >= KUsbcBufSz_Ep0Tx)
+            {
+            __KTRACE_OPT(KPANIC,
+                         Kern::Printf("  Error: No Tx buffer space left -> stopping here"));
+            break;
+            }
+        buf += size;
+        }
+    __KTRACE_OPT(KUSB, Kern::Printf("  copied %d bytes", copied));
+    return copied;
+    }
+
+
+//
+// Put the current OTG descriptor in the Ep0 Tx buffer.
+// Only used for Ep0 standard requests, so target buffer can be hard-wired.
+//
+TInt TUsbcDescriptorPool::GetOtgDescriptor() const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetOtgDescriptor()"));
+    if (iDescriptors[KDescPosition_Otg] == NULL)
+        {
+        __KTRACE_OPT(KUSB, Kern::Printf("  OTG Descriptor not set"));
+        return 0;
+        }
+    return iDescriptors[KDescPosition_Otg]->GetDescriptorData(iEp0_TxBuf, KUsbcBufSz_Ep0Tx);
+    }
+
+
+//
+// Put a specific String descriptor in the Ep0 Tx buffer.
+// Only used for Ep0 standard requests, so target buffer can be hard-wired.
+//
+TInt TUsbcDescriptorPool::GetStringDescriptor(TInt aIndex) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetStringDescriptor(%d)", aIndex));
+    // I really would have liked to display the descriptor contents here, but without trailing zero
+    // we got a problem: how can we tell printf where the string ends? We would have to
+    // dynamically allocate memory (since we don't know the size in advance), copy the descriptor
+    // contents there, append a zero, and give this to printf. That's a bit too much effort...
+    if (!StringDescriptorExists(aIndex))
+        {
+        return 0;
+        }
+    return iStrings[aIndex]->GetDescriptorData(iEp0_TxBuf, KUsbcBufSz_Ep0Tx);
+    }
+
+
+//
+// Write a String descriptor pointed to by the Device descriptor to the user side
+// (one of Manufacturer, Product, SerialNumber).
+//
+TInt TUsbcDescriptorPool::GetDeviceStringDescriptorTC(DThread* aThread, TDes8& aString,
+                                                      TInt aIndex, TInt aPosition) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::GetDeviceStringDescriptorTC()"));
+    const TInt str_idx = iDescriptors[KDescPosition_Device]->Byte(aIndex);
+    if (str_idx)
+        {
+        __ASSERT_ALWAYS((str_idx == aPosition), Kern::Fault(KUsbPanicCat, __LINE__));
+        __KTRACE_OPT(KUSB, Kern::Printf("  String @ pos %d (device $): \"%S\"",
+                                        str_idx, &iStrings[str_idx]->StringData()));
+        return Kern::ThreadDesWrite(aThread, &aString,
+                                    iStrings[str_idx]->StringData(), 0);
+        }
+    else
+        {
+        __KTRACE_OPT(KUSB, Kern::Printf("  No string descriptor @ pos %d", aIndex));
+        return KErrNotFound;
+        }
+    }
+
+
+//
+// Read a Device String descriptor from the user side and put in the descriptor arrays
+// (one of Manufacturer, Product, SerialNumber).
+//
+TInt TUsbcDescriptorPool::SetDeviceStringDescriptorTC(DThread* aThread, const TDes8& aString,
+                                                      TInt aIndex, TInt aPosition)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::SetDeviceStringDescriptorTC()"));
+    // we don't know the length of the string, so we have to allocate memory dynamically
+    TUint strlen = Kern::ThreadGetDesLength(aThread, &aString);
+    if (strlen > KUsbStringDescStringMaxSize)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Warning: $ descriptor too long - will be truncated"));
+        strlen = KUsbStringDescStringMaxSize;
+        }
+    HBuf8* const strbuf = HBuf8::New(strlen);
+    if (!strbuf)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Memory allocation for dev $ desc string failed (1)"));
+        return KErrNoMemory;
+        }
+    strbuf->SetMax();
+    // the aString points to data that lives in user memory, so we have to copy it:
+    const TInt r = Kern::ThreadDesRead(aThread, &aString, *strbuf, 0);
+    if (r != KErrNone)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Thread read error"));
+        delete strbuf;
+        return r;
+        }
+    TUsbcStringDescriptor* const sd = TUsbcStringDescriptor::New(*strbuf);
+    if (!sd)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Memory allocation for dev $ desc failed (2)"));
+        delete strbuf;
+        return KErrNoMemory;
+        }
+    ExchangeStringDescriptor(aPosition, sd);
+    iDescriptors[KDescPosition_Device]->SetByte(aIndex, aPosition);
+    delete strbuf;
+    return r;
+    }
+
+
+//
+// Remove a Device String descriptor from the descriptor arrays
+// (one of Manufacturer, Product, SerialNumber).
+//
+TInt TUsbcDescriptorPool::RemoveDeviceStringDescriptor(TInt aIndex, TInt aPosition)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::RemoveDeviceStringDescriptor()"));
+    if (iDescriptors[KDescPosition_Device]->Byte(aIndex) == 0)
+        {
+        __KTRACE_OPT(KUSB, Kern::Printf("  RemoveDeviceStringDescriptor: no $ desc @ index %d", aIndex));
+        return KErrNotFound;
+        }
+    ExchangeStringDescriptor(aPosition, NULL);
+    iDescriptors[KDescPosition_Device]->SetByte(aIndex, 0);
+    return KErrNone;
+    }
+
+
+//
+// Puts aDesc at postion aIndex in the string descriptor array, after deleting what was (possibly) there.
+//
+void TUsbcDescriptorPool::ExchangeStringDescriptor(TInt aIndex, const TUsbcStringDescriptor* aDesc)
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::ExchangeStringDescriptor()"));
+    TUsbcStringDescriptorBase* const ptr = iStrings[aIndex];
+    __KTRACE_OPT(KUSB, Kern::Printf("  Deleting string descriptor at index %d: 0x%x", aIndex, ptr));
+    iStrings.Remove(aIndex);
+    delete ptr;
+    __KTRACE_OPT(KUSB, Kern::Printf("  Inserting string descriptor at index %d: 0x%x", aIndex, aDesc));
+    iStrings.Insert(aDesc, aIndex);
+    }
+
+
+//
+// Checks whether there are any string descriptors in the array (apart from LangID).
+//
+TBool TUsbcDescriptorPool::AnyStringDescriptors() const
+    {
+    const TInt n = iStrings.Count();
+    for (TInt i = 1; i < n; i++)
+        {
+        if (iStrings[i] != NULL)
+            return ETrue;
+        }
+    return EFalse;
+    }
+
+
+//
+// Returns true if aIndex exists and what is at that positition is not a NULL pointer.
+//
+TBool TUsbcDescriptorPool::StringDescriptorExists(TInt aIndex) const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::StringDescriptorExists()"));
+    if (aIndex >= iStrings.Count())
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: Bad string index: %d", aIndex));
+        return EFalse;
+        }
+    else if (iStrings[aIndex] == NULL)
+        {
+        __KTRACE_OPT(KPANIC, Kern::Printf("  Error: No $ descriptor @ pos %d", aIndex));
+        return EFalse;
+        }
+    return ETrue;
+    }
+
+
+//
+//
+//
+TInt TUsbcDescriptorPool::FindAvailableStringPos() const
+    {
+    __KTRACE_OPT(KUSB, Kern::Printf("TUsbcDescriptorPool::FindAvailableStringPos()"));
+    const TInt n = iStrings.Count();
+    // We don't start from 0 because the first few locations are 'reserved'.
+    for (TInt i = KStringPosition_FirstAvailable; i < n; i++)
+        {
+        if (iStrings[i] == NULL)
+            {
+            __KTRACE_OPT(KUSB, Kern::Printf(" Found available NULL position: %d", i));
+            return i;
+            }
+        }
+    return -1;
+    }
+
+
+// -eof-