1. Making Windows CE.net Work With Custom Platforms James Y. Wilson

2. Brief Biography
Lead software engineer for integration of CE on various custom platforms
Various publications on Windows CE system development
Coauthor of “Building Powerful Platforms With Windows CE” published by Addison-Wesley in Q4 1999
Microsoft Embedded MVP
Developer of Windows 3.x/9x/NT device drivers

3. Agenda Introduction to CE OS Architecture
Steps to adaptation for custom platforms
Tool-chain
Real-time capabilities and limitations
Licensing options

4. Windows CE (In a Nut Shell)
32 bit, preemptive, multithreaded
“Real-Time”
Used for implementation of PocketPC devices (PDAs, Phone Edition, SmartPhone devices)
Platform configurations for:
Industrial controllers
Web pads
Gateways
Internet appliances
PDAs
Mobile/IP Phones
Set top boxes

5. Available Apps and Services
End user apps
Viewers (Excel, Word, PowerPoint, Image, and PDF)
Inbox
Pocket Internet Explorer (PIE)
Internet Explorer (based on IE 6.0)
Remote Desktop
Terminal Emulation
VoIP
Windows Messenger
WordPad
MediaPlayer
Installers
More!
Service components
C/C++ libraries and runtime (exception handling, RTTI)
COM/DCOM
Active Template Library
.NET CF
SNMP
LDAP
Microsoft Message Queuing
MFC
OBEX
SOAP, XML (HTTP, XQL, XSLT, SAX)
SQL Server CE
Shells (console, graphical, skinnable, speech)

6. Windows CE Versions Windows CE 1.0 Windows CE 2.0
Released fall 1996
Windows CE 2.0
Released 1997
2.01 (service pack for 2.0)
Windows CE 2.1 Upgrade from Windows CE 2.0
2.11 Introduced in 1998
Windows CE 3.0
Released 2000
Windows CE.net 4.0
Released 2002
Windows CE.net 4.2
Released 2003

7. Target Hardware Minimum hardware requirements Reference Platforms
Memory Management Unit for paged virtual memory
Timer
Certified 32 bit processor (ARM cores, MIPS, PPC, SH, x86)
Reference Platforms
Priced from $200 for x86 platform
Provides “Board Support Package”
Many single board computers and reference designs

8. OS Architecture Microsoft OEM ISV, OEM Applications WIN32 APIs
COREDLL, WINSOCK, OLE, COMMCTRL, COMMDLG, WININET, TAPI
Windows CE Shell Services
Remote Connectivity
Embedded Shell
Kernel
IrDA
GWES
Device Manager
File
Manager
TCP/IP
OAL
Bootloader
Drivers
Device drivers
File drivers
OEM Hardware

9. Modular OS OS divided into .exe/.dll modules (NK.exe contains kernel)
Modules further divided using .lib files
Modules run in Flash (uncompressed) or RAM (compressed in Flash, uncompressed in RAM)
ROM image sizes:
400K minimum: executive and file system
1200K: networking (IPv6, RTP, SMB/CIFS, RAS/PPP, WLAN, BT), no graphics
4MB: +graphics, basic shell
6MB: +hand writing recognition, etc.

10. Stack (reserved space)
Virtual Address Space
FFFF FFFF
03FF FFFF
COREDLL.DLL
Other ROM DLLs
NK “Slot” C
Kernel Space
XIP DLL space
Large Memory Area
(memory mapped files)
non-ROM DLLs
Slot 32
Process 32
Slot 31
Process 31 3E .
Free virtual space
Stack (reserved space)
Heap (reserved space)
Resources
Read write data
Slot 3
Process 3
Read only data
Slot 2
Process 2
Code
Slot 1
Slot 0
DLLs
Act. Process
reserved

11. Steps for Adaptation to a Custom Platform
Boot loader development
OEM Adaptation Layer (OAL)
Device driver development
Selection/development of application suite
Test and validation
Platform SDK generation

12. Bootloader Technically not required for production build
Performs minimal processor and memory initialization
Configures debug ports
Downloads OS image into RAM if debug (from TFTP server, serial, or parallel ports)
Vector to ROM if production or disconnected, otherwise RAM
Optionally provide OS update utility
Many examples provided in Platform Builder (dialup bootloader with security)

13. OEM Adaptation Layer Contains platform specific code
Performs platform initialization
ISR (support for nested interrupts)
Implements power management
Provides specified services called by Kernel
Statically linked at build time to kernel (NK.exe)

14. OEM Adaptation Layer (2/2)
Source examples provided for various reference platforms
Available from 3rd parties in Board Support Package (BSP)

15. Device Classes
Defined: Devices which share common attributes grouped to form a category or “class”
Enables congregation of common driver code (class/miniport model)
New device classes defined by Microsoft
Because primary calling module, GWES, not provided in source form

16. Device Classes (continued)

17. Device Driver Models
Defined: Common mechanism for constructing interfaces between identified driver layers
Not an API, but a mechanism supported by a defined API
CE supports certain Windows 9x/NT driver models, other driver models unique to CE
ISV’s and IHV’s may define new driver models

18. Device Driver Models (continued)
Windows CE supported driver models
Stream-interface
NDIS 4.0
Printer Miniport (partial)
Native
Windows NT ACM
USB

19. Device Driver Architecture
Device Manager
Stream-interface
Stream-interface
Stream-interface Driver
MDD
Native Driver
DDSI
Card Services
PDD
Stream-interface
NDIS Wrapper
Stream-interface
USB Interface
NDIS
NDIS Miniport
USBD
USB Driver
Card Services
NDIS Wrapper
HCD

20. Device Driver Architecture (Continued)
GWE Subsystem
DDI
DDI
Monolithic Device Driver
MDD
Native Driver
Defined by Microsoft
DDSI
PDD

21. Device Driver Architecture (Continued)
Consists of DLL’s and object module libraries
Drivers run in user mode
Allows access to application level resources (MFC, COM, ATL, etc.)
Prevents kernel crashes due to driver exceptions
Supports software assisted driver debugging

22. Device Manager Primarily dedicated to Stream-interface Drivers
Loading and unloading
Translation of application level calls
Power management notifications
Enumeration of PC Card devices
Exists in a separate process space
Implications for buffer pointers
Single driver instance shared by all calling applications

23. Stream-interface Driver Model
Used most commonly
Basis of certain driver models (ex.: USB and NDIS)
Supports installable devices
Standard Win32 file I/O interface
Exposed only through the Device Manager
Often used in combination with the Native Driver Model

24. Stream-interface Driver Model (Continued)
Required entry points (XXX = Device File Name) in approximate order of initialization:
XXX_Init
XXX_IoControl
XXX_Open
XXX_Read
XXX_Write
XXX_Seek
XXX_PowerUp
XXX_Deinit
XXX_Close
XXX_PowerDown

25. Native Driver Model Supports onboard devices only
Provides class/miniport layering
Model Device Driver (MDD) layer
Provided by Microsoft
Communicates with GWES and kernel
Handles interrupts
Platform Dependent Driver (PDD) layer
Contains code to access the hardware
Focus of changes for integration of CE with a custom platform

26. Other Device Driver Models
Services.exe, intended for non-device related modules
USB Driver Model
NDIS 4.0 miniport
Printer miniport
Audio Compression Manager
Many drivers implemented using a hybrid driver model (ex.: RS-232 serial driver)
Implementation of custom driver models possible
Driver Control Program (DCP) must be defined (ex.: USBD.dll)

27. Processing Interrupts
Different for installable devices (ex.: PC Card and USB)
For onboard devices, first processed by an ISR in the OAL
Lower priority interrupts disabled while in ISR, with nesting of higher priority interrupts
Interrupt Service Thread (IST) is signaled
IST generally running at high priority, do not block on resources in lower priority threads

28. Processing Interrupts

29. Accessing Physical Resources
Must request user mode address mapped to physical memory
May use functions available in CEDDK.LIB
Other driver models provide similar functions
Example source...

30. Accessing Physical Resources
#define UNCACHED_OFFSET 0x
#define UNCACHEDMEMORY(address) (address |\
UNCACHED_OFFSET)
#define MY_DEVICE_FRAME_BUFFER xB0000
#define MY_DEVICE_FRAME_BUFFER_LENGTH 0x20000
PVOID pMappedMemory = MmMapIoSpace((PHYSICAL_ADDRESS)
UNCACHEDOFFSET(MY_DEVICE_FRAME_BUFFER),
(ULONG)MY_DEVICE_FRAME_BUFFER_LENGTH,
FALSE);
ASSERT(pMappedMemory != NULL);
...
MmUnmapIoSpace(pMappedMemory,
(ULONG)MY_DEVICE_FRAME_BUFFER_LENGTH);

31. Platform Builder Platform Configuration Module Development
Used to select modules in OS image
Configures link and locate
Wizard provided to begin with reference platform
Module Development
Supports device driver and application development
Built separately from OS image

32. Platform Builder (2/3) Debugging
Configurable connections to platform (TCP/IP, ActiveSync, Serial, or custom)
Single step and conditional break points
Support for hardware-assisted debugging (useful for OAL)
Process, thread, module, and memory windows
Tracking of kernel state
Call profiling

33. Platform Builder (3/3) Builds ROMable OS image
Provides emulation to load and test OS image
Supports creation of custom “Platform SDK”
Demo: Emulator, Break point, process viewer, Kernel Tracker, call profiling

34. Platform Builder Demo

35. Other Tools eMbedded Visual C++ 3.0 eMbedded Visual C++ 4.0
Used for Pocket PC 2002 (CE 3.0 devices) and earlier
eMbedded Visual C++ 4.0
Used for Pocket PC 2003 (CE 4.0 devices) and later
Visual Studio.net
Used for managed code development (.net Compact Framework)
Both eVC products to be merged with Visual Studio
Free download status of eVC in question
Windows CE Test Kit (CETK, see downloads) for scriptable application and system testing

36. Real Time Capabilities
256 priority levels
Scheduler granularity of 1 millisecond
Thread Quantum defined independent of timer tick (set to 0 for run to completion)
Decouples thread quantum (time slice) from timer tick
Nested interrupts
ROM compression optional (avoids page faults)
Multiple XIP regions
Full kernel mode supported
Priority Boosting

37. Real-Time Capabilities* (2/2)
SH4 198MHz Windows CE 3.0
Pentium 100 MHz Windows CE 3.0
Pentium 100 MHz Windows CE 3.0+QFE
ISR Min [us]
0.9
1.9
ISR Max
9.1
5.7
ISR Average
2.9
2.8
IST Min
14.8
12.9
9.6
IST Max
54.3
163.3
55.6
IST Average
38.2
28.7
26.4
Jitter Max 40
150 46
*Source:

38. Licensing Options Platform Builder cost $995/seat
Windows CE Royalty begins at $3
Shared Source Licensing
Allows non commercial derivatives
Allows debugging commercial products
Redistribution program available CE devices
See “Web Sites” for additional reference

39. Downloads
Platform Builder Evaluation Kit
eMbedded Visual C eMbedded Visual C
All other downloads (including CETK)

40. Documents CE Real Time research docs
Real-Time Evaluation by Dedicated Systems:
Real-Time and Windows Embedded:
Windows Embedded Real-Time:
Performance Test Methodologies for Windows CE .NET
Designing and Optimizing Microsoft Windows CE .NET for Real-Time Performance

41. Web Sites Product Overview Shared Source License Information
Shared Source License Information
Runtime Licensing Model for CE .NET 4.2
Development Community Web Sites
WindowsForDevices.com:
Pocket PC Developer Network:
The Code Project:
Evangelist Web Sites
Pocket PC Passion:
CE Windows.NET:

42. Conclusion Modular operating system
Various driver models with nested interrupts
Custom Kernel Image through PB
Flexible Real-Time performance characteristics
Low cost licensing
CE’s total integration advantage