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ACPI In Windows Vista Allen Marshall Lead Program Manager Windows Core Platform Architecture Microsoft Corporation.

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Presentation on theme: "ACPI In Windows Vista Allen Marshall Lead Program Manager Windows Core Platform Architecture Microsoft Corporation."— Presentation transcript:

1 ACPI In Windows Vista Allen Marshall Lead Program Manager Windows Core Platform Architecture Microsoft Corporation

2 Agenda ACPI Support in Windows Vista ACPI Version support Machine Role Flags Screen Brightness _OSI Processor Power Management PCI Express ACPI Driver Interface ACPI Test and Debugging Common ACPI Errors

3 ACPI Support In Windows Overview Windows Vista requires ACPI Non-ACPI HALs are not available in Windows Vista Legacy power management and BIOS configuration implementations are no longer supported Both ACPI and Windows have seen continual advancements ACPI offers significant system advantages Close platform integration with the operating system Greatly increased reliability, diagnosability Windows ACPI support promotes faster system development Rich ACPI feature support Extensive ACPI debugging support ACPI table overload for rapid system bring-up

4 ACPI Support In Windows Microsoft ASL compiler update Updated ASL compiler now available Version 3.0.0 released Supports ACPI 2.0, 3.0 objects required for Windows Vista Provides several features to facilitate development and debugging Saves ACPI tables from firmware to disk file Un-assembling AML into ASL Loading ACPI tables from disk, bypassing BIOS ROMs See details later in this presentation Available for download from Windows Hardware and Driver Central (WHDC)

5 ACPI In Windows Vista ACPI version support Windows Vista supports select objects from ACPI 2.0, 3.0 specifications Windows operating systems typically do not support all features of any one version of the ACPI specification Key elements from ACPI are selected to support development of emerging hardware, e.g. PCI Express Mobile dual core processors High Performance Event Timers (HPET)

6 ACPI In Windows Vista Using RSDT versus XSDT In Windows Vista, if the RSDP Revision field is > 2 Windows will use the XSDT in place of the RSDT Windows will calculate the checksum of the entire RSDP Must match the Extended Checksum field Ensure your XSDT address is valid if you report Revision > 2 in the RSDP Leverage the RSDP to support both older and newer operating systems RSDT can point to tables with older version support XSDT points to newer tables

7 ACPI In Windows Vista FADT implementation details If the FADT Revision field is > 2, Windows Vista will use the extended 64-bit addresses in the FADT X_FIRMWARE_CTRL and X_DSDT Extended addresses of ACPI fixed hardware X_PM1a_EVT_BLK, etc. DSDT Revision field is used to enable ACPI 2.0 and greater interpreter support A Revision > 1 enables interpreter support for ACPI 2.0 and greater All integers are treated as 64-bit in ASL

8 ACPI In Windows Vista ACPI interpreter support The Windows Vista AML interpreter features expanded implicit source data type conversion Only enabled for a subset of opcodes Index() Two-operand logical operators Introduction of this change is constrained to limit incompatibilities with existing ASL As a best practice, leverage using explicit conversion functions in your ASL to ensure the type correctness, e.g. ToBuffer()ToInteger() See “Debugging type mismatch warnings” in the Backup section of this presentation

9 ACPI In Windows Vista Screen brightness Laptop LCD brightness controls today are often implemented with proprietary interfaces SMM, Embedded Controller firmware May required 3rd party driver to enable Fn+n hot keys Breaks on OS upgrade No in-box support after clean OS install Not easily debugged OEM code maintenance burden Leveraging ACPI makes tight integration with the operating system easy Simplifies the implementation Reduces development and support costs Enhances reliability Improves customer experience

10 ACPI In Windows Vista Screen brightness Windows Vista supports the ACPI Appendix B screen brightness objects _BCL, _BCM Screen brightness levels are controlled via Vista power policy When _BCL, _BCM are present Separate brightness levels for each power policy, and for AC and DC

11 ACPI In Windows Vista Screen brightness Vista provides a temporary override to control brightness Slider control in Windows Mobility Center WMI interface exposed to control screen brightness Get and set the current brightness level Notification on change events Allows for custom controls For details, refer to the white paper “Integrating with Windows Vista Power Management”

12 ACPI Support In Windows Machine role flags Windows Vista leverages the FADT Preferred_PM_Profile flags Allows platform firmware to indicate to OSPM if the system is mobile, desktop, server, etc. Enables Windows to accurately determine the default power policy for the system Previous Windows operating systems determine a mobile PC based on the presence of a long-term battery Vista falls back to this if Preferred_PM_Profile is 0

13 ACPI Support In Windows Machine role flags Used throughout Windows Vista to make mobile versus desktop determination e.g., disable Hybrid Sleep on mobile PCs Exposed to application software through new Win32 API PowerDeterminePlatformRole()

14 ACPI Support In Windows Operating system interface _OSI method can be used to determine the version of Windows running on the system Windows Vista string is: “Windows 2006” OS vendor is the only interface string supported by Windows Vista Windows will return “true” for all OS interface levels supported Other _OSI strings Windows 2000: “Windows 2000” Windows XP RTM: “Windows 2001” Windows XP SP1: “Windows 2001 SP1” Windows XP SP2: “Windows 2001 SP2” Windows Server 2003: “Windows 2001.1” Windows Server 2003 SP1: “Windows 2001.1 SP1”

15 ACPI In Windows Vista Processor power management ACPI 3.0 domain dependency objects For multi-processor systems, these describe any of the relationships between Physical packages Physical cores Logical cores Describes how OSPM must coordinate state transitions Performance states, idle sleep states, throttle states

16 ACPI In Windows Vista Processor power management Methods supported _PSD (CPU performance state dependency) _TSD (CPU throttle state dependency) _CSD (CPU idle state dependency) C-states on systems with more than one CPU must be hardware coordinated _CSD must report CoordType 0xFE HW_ALL Otherwise, Vista will disable all C-states deeper than C1

17 ACPI In Windows Vista Processor power management New ACPI 3.0 throttling controls Expand the control interface beyond P_BLK Allows the use of Functional Fixed Hardware address space Accommodates processor architecture-specific controls Allows dynamic throttle states Objects supported _PTC_TSS_TPC_TDC Notify (cpu, 0x82)

18 ACPI Support In Windows PCI Express Windows Vista requires _OSC on PCI Express root bridges Enables native OS control of PCI Express features Windows will first evaluate _OSC to query for supported capabilities Evaluate _OSC again to assume control Firmware must grant native OS control of all control field feature bits, otherwise Windows takes control of none ASPM Hot plug Power Management Event (PME) Advanced Error Reporting For details, see CPA070 “PCI Express In Depth for Windows Vista”

19 ACPI Support In Windows PCI Express errata flags Normally, _OSC should control these features Windows Vista will look for FADT flags to globally disable some PCI Express features Message-signaled interrupts Active State Power Management These flags are intended as a temporary, stop-gap mechanism These features are required per spec

20 ACPI Support In Windows PCI Express FADT errata flags However, as PCI Express development continues, there are a number of systems that fail to work correctly This necessitates a platform firmware override mechanism The need for these flags will diminish as PCI Express chipset development matures Future versions of Windows may require these flags to be clear

21 ACPI Support In Windows PCI Express and legacy GPE Don’t assert legacy GPE bits when Windows is granted control of PCI Express PME Firmware must not assert legacy GPE to notify OSPM of device wake Windows is granted control of PCI Express Hot Plug If system wakes from PCI Express device, set PCIEXP_WAKE_STS bit in PM1_STS register Required to accurately notify Windows Vista of platform wake source

22 ACPI Support In Windows Reporting wake sources It is important that platform firmware correctly reports wake sources ACPI Fixed Feature hardware GPE status bits PCI Express device Ensure your GPE handler issues Notify() on appropriate device Otherwise, Windows may misrepresent the system wake source

23 ACPI Support In Windows Reporting wake sources Windows Vista will log and display system wake sources Available in the system event log Can be viewed with the power command line tool powercfg.exe C:\>powercfg /lastwake Wake History Count - 1 Wake History [0] Wake Source Count - 1 Wake Source [0] Type: Device Instance Path: USB\ROOT_HUB\4&6a6c62d&0 Friendly Name: Description: USB Root Hub Manufacturer: (Standard USB Host Controller)

24 ACPI Support In Windows Reporting wake sources Example – system event log entry

25 - Data 2006-04-07T02:37:27.841Z [ Name] SleepTime - Data 2006-04-07T16:30:55.390Z [ Name] WakeTime - Data 7660 [ Name] SleepDuration - Data 595 [ Name] WakeDuration - Data 5945 [ Name] DriverInitDuration - Data 576 [ Name] BiosInitDuration - Data 147 [ Name] HiberWriteDuration - Data 0 [ Name] HiberReadDuration - Data 0 [ Name] HiberPagesWritten - Data 0 [ Name] Attributes - Data 4 [ Name] TargetState - Data 4 [ Name] EffectiveState - Data 3 [ Name] WakeSourceType - Data 17 [ Name] WakeSourceTextLength - Data ACPI Sleep Button [ Name] WakeSourceText ACPI Support In Windows Reporting wake sources Example – system event log wake details

26 ACPI Support In Windows Reporting wake sources Carefully handle unattended wake events When a machine wakes due to an PME# event or a remote event, BIOS ASL should not issue a Notify(btn, 0x02) to the fixed feature power button in order to wake the monitor This indicates User Present to Windows The power manager will Turn on the display Exit Away Mode, if enabled Apply the current power policy for system idle timeout This can break power management scenarios Consider a Media PC

27 ACPI Support in Windows ACPI Driver Interface Currently drivers can call IOCTL_ACPI_EVAL_METHODIOCTL_ACPI_ASYNC_EVAL_METHOD Requires a handle to device you want to evaluate method for No capability to enumerate or evaluate control methods of child devices Workarounds often involve redundant information in namespace

28 ACPI Support in Windows ACPI Driver Interface Windows does not allow arbitrary execution of control methods Drivers should not evaluate methods on devices they have no knowledge of Breaks rules of encapsulation Leads to system instability Compromise: Allow control method execution on child devices beneath the device handle opened Device should have knowledge of child devices Allows for cleaner BIOS code in the future No need to duplicate information in namespace

29 ACPI Support In Windows ACPI Driver Interface New IOCTLs to enumerate and evaluate child device control methods IOCTL_ACPI_EVAL_METHOD_EXIOCTL_ACPI_ASYNC_EVAL_METHOD_EX Take an additional “Name” field Relative in namespace to the device you have a handle to Can be arbitrarily deep Support passing/returning 64-bit integers

30 ACPI Support In Windows ACPI Driver Interface IOCTL_ACPI_ENUM_CHILDREN Allows enumeration of one level, or multi-level Supports passing in a filter Only return specific children e.g., return only children with _STA method Returns back an array of child nodes Flags indicate if a child has descendent

31 ACPI Support In Windows ECDT Table ECDT – EC Boot Resource Table Provides processor-relative resources of an Embedded Controller Allows EC op region access before the entire namespace has been evaluated Without this table, EC region space is not available until EC device is enumerated Verify by providing a _REG method under the EC Windows Vista will return 2 when _REV is evaluated Indicates firmware should use ECDT

32 ACPI Test And Debugging Extracting ACPI tables The Microsoft ASL compiler supports exporting ACPI tables and saving them to a disk file Extracted as ASL Tables may be modified, temporarily re-loaded on a system Facilitates development and debugging Intended only as a firmware development aid – not for deployment! Usage asl /tab=DSDT Produces DSDT.asl - or – Asl /=tab* Produces ACPI.TXT (all tables)

33 ACPI Test And Debugging Loading ACPI tables Tables may be loaded from the registry instead of from BIOS ROM Requires the checked version of acpi.sys The table to be overloaded must already be present in the system's BIOS ROM For instance, the DSDT can be overloaded If the machine does not have an SSDT, you cannot force an SSDT to be loaded from this registry override mechanism The table with the highest version number will be loaded The table loaded into the registry for testing must have a higher version number than the same table in the BIOS ROM

34 Common ACPI Errors BIOS using OS memory Windows Vista validates ACPI memory type definitions Microsoft has seen instances of firmware accessing OS memory This is a fatal error Stop 0xA5 (ACPI_BIOS_ERROR) 0x1000

Seen when additional memory added to systems Carefully design for top of memory range

35 Common ACPI Errors BIOS using OS reclaim memory Windows Vista validates ACPI memory type definitions During development, Microsoft discovered instances of table load from ACPI reclaim memory ACPI reclaim memory is available for OS use after ACPI mode has been enabled Problem is that memory operation region is mapped as ACPI reclaim This is incorrect, per the ACPI specification Load opcode was clarified in ACPI 3.0a Common error in example code for handling processor power management capabilities OEMs and system designers should obtain the latest processor power management ACPI reference code from your processor vendor

36 Common ACPI Errors GPE index out of range Windows Vista validates the index of general-purpose event bits (GPEs) GPE indexes referenced must be within the length of the GPE register blocks Validation failure results in a fatal system error Stop 0xA5 (ACPI_BIOS_ERROR) Subcode 1 = 0x17 ACPI_INVALID_GPE_INDEX Subcode 2 = GPE bit index specified

37 Common ACPI Errors Memory corruption during sleep During Vista development, BIOS corruptions of the low 1MB of memory were observed across suspend/ resume transitions BIOS developers need to ensure that their code does not have this issue Detect this problem with Driver Verifier

38 Common ACPI Errors Memory corruption during sleep This check is automatically enabled on checked builds System checksums low 1 MB of memory before, after suspend/resume Corruption results in stop error 0xC4 DRIVER_VERIFIER_DETECTED_VIOLATION Subcode 0xB7 indicates the BIOS has corrupted low physical memory Parameters 2,3,4: Number of corrupt pages, first corrupt page, last corrupt page

39 Common ACPI Errors Update table versions Be sure to update OEM Revision field in your table headers Windows applies BIOS work-arounds based on this revision Failure to update this revision may result in loss of functionality Example: BIOS known to have problems with PCI Express ASPM has this feature disabled Updated ACPI BIOS corrects the problem, but fails to update OEM Revision in description header Windows will continue to disable this feature

40 Call To Action Ensure your systems properly support ACPI for Windows Vista Leverage ACPI in place of proprietary solutions wherever possible Test your ACPI implementations using checked builds or with Driver Verifier enabled Take advantage of Microsoft’s ASL compiler and debugger extensions to facilitate ACPI development

41 Additional Resources Web Resources White papers, other resources pnppwr/powermgmt/default.mspx pnppwr/powermgmt/default.mspx pnppwr/powermgmt/default.mspx Microsoft ACPI Source Language (ASL) Compiler v3.00 ACPI Specification: Related Sessions CPA075 Power Management in Windows Vista CPA060 Kernel Plug and Play Support in Windows Vista CPA070 PCI Express in Depth for Windows Vista and Beyond For questions about ACPI in Windows, contact Microsoft at: aslhelp @

42 Backup PCI Express FADT override flags BOOT_ARCH Bit Lengt h Bit Offset Description LEGACY_DEVICES10 If set, indicates that the motherboard supports user-visible devices on the LPC or ISA bus. User-visible devices are devices that have end-user accessible connectors (for example, LPT port), or devices for which the OS must load a device driver so that an end-user application can use a device. If clear, the OS may assume there are no such devices and that all devices in the system can be detected exclusively via industry standard device enumeration mechanisms (including the ACPI namespace). 804211 If set, indicates that the motherboard contains support for a port 60 and 64 based keyboard controller, usually implemented as an 8042 or equivalent micro-controller. VGA Not Present 12 If set, indicates to OSPM that it must not blindly probe the VGA hardware (that responds to MMIO addresses A0000h-BFFFFh and IO ports 3B0h-3BBh and 3C0h-3DFh) that may cause machine check on this system. If clear, indicates to OSPM that it is safe to probe the VGA hardware. MSI Not Supported13If set, indicates to OSPM that it must not enable Message Signaled Interrupts (MSI) on this platform. PCIe ASPM Controls14If set, indicates to OSPM that it must not enable ASPM on this platform. Reserved115 Must be 0.

43 Backup ACPI Debugging Debugging Tools for Windows can be used to debug issues with ASL Microsoft provides a kernel debugger extension that enables AML debugging Included with Debugging Tools for Windows Some commands required the checked acpi.sys

44 Backup ACPI Debugging – Common Commands !amli find !amli find Finds all objects in the ACPI namespace with the specified name !amli dns /s !amli dns /s Displays the specified namespace object and all elements underneath !amli u !amli u Unassembles the corresponding ACPI method into ASL opcodes !amli lc !amli lc Lists all the AML contexts currently inside the interpreter; the running context is denoted with a “*” in the beginning of the entry line !amli ds !amli ds Displays the interpreter stack in the current running context !nsobj Displays namespace object information These commands are available in the retail (fre) version of the acpi.sys driver

45 Backup ACPI Debugging – Common Commands !amli ln | !amli ln | Unassembles the nearest method to the specified line !amli set !amli set Sets a variety of options related to ACPI debugging, such as turning spew on, break on error, break on namespace loading time, etc. !amli [bp | bl | bc | bd | be] !amli [bp | bl | bc | bd | be] Commands that work with AML Breakpoints functioning exactly like the equivalent commands inside regular kd environment !amli [p | t] !amli [p | t] Steps/traces over a line of AML code !amli r !amli r Displays the current context info, including local variables These commands require the checked version of the acpi.sys driver

46 Backup ACPI Debugging – Example 1 Determine why a device is not wake-capable 0: kd> !devstack 0x837d4b98 !DevObj !DrvObj !DevExt ObjectName !DevObj !DrvObj !DevExt ObjectName 837de020 \Driver\pci 837de0d8 837de020 \Driver\pci 837de0d8 837d55e8 \Driver\ACPI 837ceb70 837d55e8 \Driver\ACPI 837ceb70 > 837d4b98 \Driver\pci 837d4c50 NTPNP_PCI0003 !DevNode 837daa88 : DeviceInst is "PCI\VEN_xxxx&DEV_yyyy&SUBSYS_00000000&REV_xx\a&123b45cd&6&e7" DeviceInst is "PCI\VEN_xxxx&DEV_yyyy&SUBSYS_00000000&REV_xx\a&123b45cd&6&e7" ServiceName is "pci“ ServiceName is "pci“ 2. From the !devstack output we can get the ACPI device extension 0: kd> dt acpi!_DEVICE_EXTENSION 837ceb70.... +0x164 RemoveEvent : (null) +0x164 RemoveEvent : (null) +0x168 AcpiObject : 0x837c4070 _NSObj +0x168 AcpiObject : 0x837c4070 _NSObj +0x16c DeviceObject : 0x837d55e8 _DEVICE_OBJECT +0x16c DeviceObject : 0x837d55e8 _DEVICE_OBJECT.... 1. We know this device is a PCI bus, and from the output of !pcitree, we get the following !devstack

47 3. From the ACPI device extension, we can see the namespace object corresponding to it 0: kd> !nsobj 0x837c4070 nsobj: dumping object at 837c4070 NameSpace Object PCI3 (00000000837c4070) – Device ffffffff837ceb70 Flink ffffffff837c4ce8 Blink ffffffff837c33f8 Flink ffffffff837c4ce8 Blink ffffffff837c33f8 Parent ffffffff837c0920 Child ffffffff837c40bc Parent ffffffff837c0920 Child ffffffff837c40bc Value 0000000000000000 Length 0000000000000000 Value 0000000000000000 Length 0000000000000000 Buffer 0000000000000000 Flags 0000000000000000 Buffer 0000000000000000 Flags 0000000000000000 Object Data - 00000000837c4090 Type – 06 Object Data - 00000000837c4090 Type – 06 4. With the namespace object of the device, we can find all namespace objects corresponding to it 0: kd> !amli find PCI3 \_SB.PCI0.PCI3 Backup ACPI Debugging – Example 1

48 5. With the full namespace path, we can now display the actual object 0: kd> !amli dns /s \_SB.PCI0.PCI3 ACPI Name Space: \_SB.PCI0.PCI3 (ffffffff837c33f8) Device(PCI3) | Method(_S1D:Flags=0x0,CodeBuff=ffffffff837c0d6d,Len=3) | Method(_S3D:Flags=0x0,CodeBuff=ffffffff837c34ed,Len=14) | Method(_S4D:Flags=0x0,CodeBuff=ffffffff837c3565,Len=14) | Method(_S5D:Flags=0x0,CodeBuff=ffffffff837c35dd,Len=14) | Method(_ADR:Flags=0x0,CodeBuff=ffffffff837c3655,Len=9) | Integer(_UID:Value=0x0000000000000016[22]).... 6. From examining the namespace object we can see the object does not have capability to wake the system, since no _PRW package is present.

49 Backup ACPI Debugging – Example 2 The system has encountered Bug Check 0x7E in acpi.sys 1. Using the kernel debugger, we examine the stack trace : 1: kd> kn *** Stack trace for last set context -.thread/.cxr resets it *** Stack trace for last set context -.thread/.cxr resets it # ChildEBP RetAddr # ChildEBP RetAddr 00 f7936cb0 f7365bae ACPI!WriteSystemMem+0x6a 01 f7936ce0 f7365d1a ACPI!AccessBaseField+0x1f7 02 f7936d04 f7365df0 ACPI!AccessFieldData+0x15c 03 f7936d2c f7367d77 ACPI!WriteFieldObj+0xcb 04 f7936d54 f7369622 ACPI!RunContext+0x65.... 2. Since the system was running in the ACPI driver, we examine the AML context that was running: 1: kd> !amli lc *Ctxt=ffffffff865be000, ThID=ffffffff865c06a0, Flgs=A--CR----, pbOp=ffffffff865af4a5, Obj=\_SB.PCI0._INI 1: kd> !amli ds ffffffff865af65b: \_SB.MSM1() ffffffff86541627: \_SB.MSM2() 0: \_SB.PCI0._INI() 3. And we display the AML interpreter’s stack and find that it was running the method \_SB.MSM1()

50 Backup ACPI Debugging – Example 2 4. From the AML context, we can see the current opcode points at ffffffff865af4a5. However this would be the next opcode run, so we unassemble \_SB.MSM1() to examine the previous opcode 1: kd> !amli u \_SB.MSM1 ffffffff865af469 : If(LEqual(^MSTB, Ones)) ffffffff865af473 : { ffffffff865af473 : | If(CondRefOf(\_OSI, Local0)) ffffffff865af47e : | { ffffffff865af47e : | | If(\_OSI("Windows 2001.1")) ffffffff865af495 : | | { ffffffff865af495 : | | | Store(0x20, ^MSV1) ffffffff865af49d : | | | Store(0x20, ^MSV2) ffffffff865af4a5 : | | } ffffffff865af4a5 : | | Else ffffffff865af4a8 : | | { ffffffff865af4a8 : | | | If(\_OSI("Windows 2001 SP1")) ffffffff865af4c1 : | | | {....

51 Backup ACPI Debugging – Example 2 5. From the unassembled AML code, we can tell the problem is within the Store(0x20, ^MSV2) call. We can display the information for ^MSV2 1: kd> !amli dns /s \_SB.MSV2 ACPI Name Space: \_SB.MSV2 (ffffffff865af3d0) FieldUnit(TPOS:FieldParent=ffffffff865af38c,ByteOffset=0x0,StartBit=0x0,NumBits=8,FieldFlags=0x0) 1: kd> !amli dns /s ffffffff865af38c ACPI Name Space: \_SB. (ffffffff865af38c) Field(:Base=MSO1) 1: kd> !amli dns /s \_SB.MS01 ACPI Name Space: \_SB.MSO1 (ffffffff865af348) OpRegion(OSTY:RegionSpace=SystemMemory,Offset=0x0,Len=-65465) 6. \_SB.MSV2 is a field unit, which is a part of the field parent \_SB.MSO1 7. From this, we can tell there is something wrong with the object \_SB.MSO1, since it has a 0 offset and a negative length. At this point we can go back to looking at the ASL to see how it is defined.

52 Backup Additional ACPI Debugger extensions !acpicache Displays all of the ACPI tables cached by the hardware application layer (HAL) !acpiinf Displays ACPI information such as the location of system tables and the contents of the ACPI fixed feature hardware !acpiirqarb Displays the contents of the ACPI IRQ arbiter structure !fadt Displays the Fixed ACPI Description Table !mapic Displays an ACPI Multiple APIC Table !rsdt Displays the ACPI Root System Description Table

53 Backup Debugging type mismatch warnings Enable the AML interpreter to break upon error Type mismatches can be caught this way !amli set errbkon Turn on full AML debugging spew !amli set spewon

54 © 2006 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.


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