diff -r 89d6a7a84779 -r 25a17d01db0c Symbian3/PDK/Source/GUID-D207C135-EF02-4D1A-A48C-4AB8C6703496-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1.dita
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Symbian3/PDK/Source/GUID-D207C135-EF02-4D1A-A48C-4AB8C6703496-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1.dita	Fri Jan 22 18:26:19 2010 +0000
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+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (c) 2007-2010 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: 
+-->
+<!DOCTYPE concept
+  PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="GUID-D207C135-EF02-4D1A-A48C-4AB8C6703496-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1" xml:lang="en"><title>Device
+Driver Structure</title><shortdesc>This document describes the structures used to implement device
+drivers as LDDs and PDDs.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>
+<p>Both LDDs and PDDs are DLLs. </p>
+<p>They implement a specific interface that allows the kernel to initialise
+them, and for user-side code to communicate with them. </p>
+<p>An LDD must implement: </p>
+<ul>
+<li id="GUID-A57D8838-EF0B-5096-99EC-D9197C58EE35-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1-3-4-1"><p>A <codeph>DLogicalChannel</codeph> or <codeph>DLogicalChannelBase</codeph> derived
+class, representing the logical channel, which handles user requests. </p> </li>
+<li id="GUID-1E3CD4B7-15BC-59B1-939B-2AF34F0438BB-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1-3-4-2"><p>A <codeph>DLogicalDevice</codeph> derived
+class, which provides a factory for the logical channel objects, called the
+LDD factory. </p> </li>
+<li id="GUID-2342FF0C-4CC0-561F-81CB-2643E09351B4-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1-3-4-3"><p>A DLL entry point function
+at ordinal 1, which constructs the LDD factory object. </p> <p>It is possible
+that a device driver is also an extension, in which case the entry point will
+also be used for extension initialisation. </p> </li>
+</ul>
+<p>A PDD must implement: </p>
+<ul>
+<li id="GUID-0D5220C0-764F-5711-970F-60D19AD21320-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1-3-6-1"><p>A <codeph>DBase</codeph> derived
+class representing the physical channel, which is the interface between the
+logical device and the physical device. </p> </li>
+<li id="GUID-BEC551B8-AED6-5EEC-8FDA-C742B4C1F7DC-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1-3-6-2"><p>A <codeph>DPhysicalDevice</codeph> derived
+class, which provides a factory for the physical channel objects, called the
+PDD factory. </p> </li>
+<li id="GUID-9D72BF3C-6D13-5D9F-A8E3-D376D445AC08-GENID-1-7-1-14-1-1-7-1-4-1-1-4-1-4-1-3-6-3"><p>A DLL entry point function
+at ordinal 1, which constructs the PDD factory object. </p> </li>
+</ul>
+</conbody></concept>
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