Bruce Eitman

Windows CE Chat Transcript (November 24, 2009)

2009-11-24T13:40:18-12:00:00

For those of you who missed the chat today, here is the raw transcript. By raw, I mean that I copied and pasted the discussion without any edits. This is divided into two parts, the top part is the answers from the Microsoft Experts and the bottom part is the questions from the audience.

Answers from Microsoft:

msft_davbo (Moderator): Our chat today covers the topic of Windows Embedded CE!

1. This chat will last for one hour. During this hour, our Experts will respond to as many questions as they can. Please understand that there may be some questions we cannot respond to due to lack of information or because the information is not yet public.

2. We encourage you to submit questions for our Experts. To do so, type your questions in the send box, select the “ask the Experts” box and click SEND. Questions sent directly to the Guest Chat room will not be answered by the Experts, but we encourage other community members to assist.

3. We ask that you stay on topic for the duration of the chat. This helps the Guests and Experts follow the conversation more easily. We invite you to ask off topic questions after this chat is over, but not during.

4. Please abide by the Chat Code of Conduct.

Chat code of conduct: <http://msdn.microsoft.com/chats/chatroom.aspx?ctl=hlp#Conduct>;

msft_davbo (Moderator): We are pleased to welcome our Experts for today’s chat. I will have them introduce themselves now.

Chat will begin in a couple of minutes.

<http://www.Microsoft.com/Embedded>;

mskim_MSFT (Expert)[12:01]: Hello, this is mskim from Windows CE JDP team.

RajeevDubey[MS] (Expert)[12:01]: Hi, this is Rajeev Dubey, Program Manager for Bluetooth.

mikehall_ms (Moderator)[12:02]: Hi, I'm Mike Hall, Software Architect

Sing Wee [MS] (Expert)[12:05]: Hello, I'm Sing Wee, member of the CoreOS/BSP Test Team.

FBlanq_MSFT (Expert)[12:05]: Hi, I'm Francisco Blanquicet, SDET with CoreOS/WinCE

msft_davbo (Moderator)[12:05]: Chat is started so ask any questions you may have about Windows CE.

rajran[MSFT] (Expert)[12:06]: Hi , I'm Rajeev Rangappa, PM in Core Team

kurtken_msft (Expert)[12:09]:

Q: [1] hi experts, is there any way to provide debug information for assembler files (.s) to the debugger so that i can step through the sources? currently only exported symbols are visible to the debugger

A: As far as I know, the only way to step into and through assembler sources is to either (1) first switch to the 'disassembly' pane of the debugger, then either set a breakpoint on a CPU instruction, or (2) switch to the disassembly view in the source view and "step into" a function call. (bl on ARM, call on X86)

kurtken_msft (Expert)[12:13]:

Q: [6] [1] so there is no way to get debug info for assembler files into the pdb files?

A: What kind of info are you wanting to get into the PDB files? What is missing and what way are you accessing information?

kurtken_msft (Expert)[12:16]:

Q: [11] [6] i know i can step i the disassembler view, but it is somewhat painful without the coments of the sourcefile. So I would like to see and step in the assembler sourcefile while debugging like when debugging c or cpp files

A: ah, so what you're wanting is a mixed assembler/code bytes view. I do not thing our tools currently have such a view for the Windows CE debugger. You would have to open a source code window side-by-side in platform builder to see the comments.

kurtken_msft (Expert)[12:17]:

Q: [12] [6] also local (not exported] labels are not known to the debugger

A: No, unfortunately local assembler labels are not accounted for in the debugging information.

kurtken_msft (Expert)[12:17]:

Q: [13] [11] well thats the way i spend most of my time

A: We can give this feedback to our tool chain developers. Thanks for the input.

mskim_MSFT (Expert)[12:22]:

Q: [15] XAML + Other Windows: I have an MFC app which contains window based user draw controls (caches and draws bitmaps and overlays data on them). I want to update the UI to use XAML. How can I embed some of these existing controls in the XAML app?

A: Here is MSDN link regarding Win32Control in Silverlight for Windows Embedded.

mskim_MSFT (Expert)[12:23]:

A: http://msdn.microsoft.com/en-us/library/ee502772.aspx

mskim_MSFT (Expert)[12:24]:

A: Yes, you can use Win32Control in Silverlight for Windows Embedded. Here is the link on msdn regarding Win32Contro. http://msdn.microsoft.com/en-us/library/ee502772.aspx

Travis Hobrla [MS] (Expert)[12:25]:

Q: [2] hi experts, i have integrated lint in the build prrocess. to see the output i have used the build_markers for C files, so they are also shown as c files in the summary. is there any way to show them with the "other files", in other words which build marker

A: Drivers should get notifications when suspend is happening if there's a driver that's not responding to a notification properly (in this case the driver for the RAM file system), you can definitely expect resource leaks or other bad behavior. Since this problem occurs only after a few suspends/resumes, I suspect that a very large amount of memory is being leaked - much more than the size of the file you're opening and closing. To debug this, I think you will want to instrument your app. As a next step, can you track the available object store space in your thread and try to understand more deeply how the memory is being used? See GetStoreInformation (http://msdn.microsoft.com/en-us/library/aa916952.aspx). After that, it may be worthwhile to turn on DEBUGZONEs in filesys.dll to see if there are any useful messages that can help you understand the situation.

Travis Hobrla [MS] (Expert)[12:25]: Ack

Travis Hobrla [MS] (Expert)[12:25]: Answered the wrong question, one moment!

Travis Hobrla [MS] (Expert)[12:26]:

Q: [10] I'm creating the file in RAMFS, and I don't believe my thread can have any leak considering it's just opening and closing the same file. Do you have any idea what could go wrong ? Thank you.

Sing Wee [MS] (Expert)[12:26]:

Q: [13] [11] well thats the way i spend most of my time

A: I just tried something similar to this. In a debug build, I break into my C code, and go to disassembly view. I see the assembly code inline with my C code and my comments, so I would expect you should be able to see your assembly code inline with your comments as well.

mskim_MSFT (Expert)[12:26]:

Q: [16] XAML + Other Windows: Effectively I want to skin the current app using XAML. Maybe there are some examples shipped with R3?

A: In R3, there is a IEsample_exr in public\ie\oak you can reference. How to skin the existing application with Silverlight for Windows Embedded.

Travis Hobrla [MS] (Expert)[12:27]: @winceLover: use "Ask the Experts"

Travis Hobrla [MS] (Expert)[12:29]:

Q: [18] hi experts, is there an easy way to enable debug zones in advance for dlls that haven't been loaded yet? Some dlls only get loaded while an application is running and by the time I get to click on Target->CE Debug Zones-><module name> it's already too late

A: I would recommend the "Host side (desktop) registry" method outlined here: http://blogs.msdn.com/ce_base/archive/2006/12/18/debug-messages-and-debug-zones-in-windows-ce.aspx

Travis Hobrla [MS] (Expert)[12:32]:

Q: [20] [10] - I will try to track the memory used in my thread more thoroughly. It's too bad I can't use KITL at that point as I'm doing suspend/resumes tests. So Travis, you're saying that there might be a leak in the RAM file system (which is public code) ?

A: It's certainly possible, but there is more investigation which is required before you can be sure.

Travis Hobrla [MS] (Expert)[12:33]:

Q: [19] Sing Wee [13] well that doesn't work for assembler files, at least in my environment, although I have to say I use trace32 vom lauterbach most of the time. But this is the behaviour i would wish for .s files.

A: It's a good feature request for the tools but I don't think we have any support for it right now. Sorry!

Travis Hobrla [MS] (Expert)[12:37]:

Q: [17] hi experts, is there a way to put additional items to the clean target without modifying makefile.def?

A: I believe the only way is during the WINCETARGETFILES or WINCETARGETFILES0 phase, you could completely override the clean rule in your own makefile.inc.

Sing Wee [MS] (Expert)[12:37]:

A: I haven't tried this over suspend/resume cycles, but have you by any chance tried using AppVerifier to see if you can catch where memory may be leaking from?

Sing Wee [MS] (Expert)[12:39]:

Q: [23] Sing Wee [19] well, perhaps there are not much assembler junkies out there , thank you any way

A: No worries. Out of curiosity, are you doing this in CE6 or CE5? My observations were based on CE6.

msft_davbo (Moderator)[12:40]:

Q: [22] We need to give camera data to the appln for displaying it on the WINCE 6.0 device LCD or we need to send the camera frames to the device USB video class for displaying at the desktop PC app.IS both my requirement will be acheived by DSHOW camera driver?

A: Yes DirectShow is the best place to build your camera application. Check Mike Hall's blog for a USB Camera Driver download http://blogs.msdn.com/mikehall/archive/2007/06/07/download-ce-6-0-usb-camera-driver.aspx. This driver allows you to pull in frames into DirectShow from a USB attached camera on Windows CE. For communicating to a Desktop you'd need to build a custom communication sink filter to send the frames from Windows CE to a corresponding custom source filter on the Desktop. If interested can post a sample on codeplex w/ details on setting up the filters send email to davbo@microsoft.com.

kurtken_msft (Expert)[12:40]:

Q: [21] What is the best way to setup a filesystem storing hive registry ? In our system, the SD card will be the storage holding it. Should we setup the SD card as MountPermanent, and are there other registry keys worth setting ?

A: Is the SD card fixed in place in your unit? If so, you should be safe to mount the card permanently. Also, make sure it is set to mount at boot time. For reference, examine some existing drivers that use persistent store for their registry

mskim_MSFT (Expert)[12:40]:

Q: Prabu, what's UVC stack?

ks [MS] (Expert)[12:40]:

A: And which public code RAMFS driver are you using? The RAMDISK, RAMFMD or?

Travis Hobrla [MS] (Expert)[12:40]:

A: In addition to what Kurt said, http://msdn.microsoft.com/en-us/library/aa914710.aspx gives you a good introduction. Basically you need to make sure the registry for your SD driver is wrapped in ;HIVE BOOT SECTION tags, as well as anything that driver depends on, so that it can get loaded in phase 0.

Sing Wee [MS] (Expert)[12:44]:

Q: [27] Sing Wee [23] i am doing CE6, porting to a OMAP platform, currently working on the bootloader, but work is proceeded to jump to BootloaderMain

A: Understood - thanks.

Sing Wee [MS] (Expert)[12:47]:

Q: [26] [20] Sing Wee : I haven't tried using AppVerifier, does it support well checking leaks while suspending/resuming the system ?

A: That's the part I haven't tried. AppVerifier keeps track of memory by monitoring calls to allocate/deallocate memory on processes/DLLs you point it at. *If* it works over suspend/resume, the checkpoint/delta feature might help you narrow down the problem more quickly. I'm having difficulty finding my original posting, but a copy of it has apparently made it here: http://www.pocketpcjunkies.com/Uwe/Forum.aspx/wince-test/481/Can-app-verifier-detect-memory-leak-in-a-driver

Travis Hobrla [MS] (Expert)[12:49]:

Q: [28] [21] - yes, this is setup correctly and works fine, until going to suspend/resume, where the SD gets unmounted and remounted. My question is : should we absolutely keep the power on to the SD card (it's never removed), and set it as MountPermanent ?

A: You should be able to call RegFlushKey (http://msdn.microsoft.com/en-us/library/aa917036.aspx) during your power-down code and unmount / remount.

msft_davbo (Moderator)[12:49]:

Q: [24] Using DSHOW layer can we give the camera frames to the client UVC stack?

A: Is you question about around if you have a Windows CE Web Camera and plug into a Desktop Machine how to provide the frames from Windows CE to the Desktop UVC Stack? Desktop MSDN info for UVC Stack http://msdn.microsoft.com/en-us/library/ee349147.aspx.

ks [MS] (Expert)[12:50]:

A: In addtion to keep the power (or handle the power cycle correctly), MountPermanent , you SD Host controller driver should never simulate a card replug after suspend/resume.

Travis Hobrla [MS] (Expert)[12:51]:

Q: [30] Travis [17] I am not sure if i understand you right, the WINCETARGETFILES targets are executed after building so not really good for cleaning, WINCETARGETFILE0 are executed before compiling, but what if only the clean target is performed?

A: Do you mean by calling 'nmake clean' ?

Travis Hobrla [MS] (Expert)[12:53]:

Q: [33] Travis [17] yes, for example, or clicking Build - Clean in VS2005

A: Unforunately I don't think there is a way to handle 'nmake clean' without modifying makefile.def. Build - Clean I believe executes "build -c" which would execute the WINCETARGETFILES0 pass - you could do cleanup at that point, before things get compiled.

Travis Hobrla [MS] (Expert)[12:56]:

Q: [34] Travis [33] ok, are there "best practices" for modifying makefile.def?

A: The 'best practice' is to make a backup, change as little as possible, and do so at your own risk! What exactly are you trying to accomplish?

Sing Wee [MS] (Expert)[12:56]:

Q: [31, 29] Can you point me to the KB entry or tell us what exactly has to be adapted in the OAL Cache routine?
In a previous QFE adressing the L2 cache it is documented that one has to adapt the OAL Cache routines. To found out how we were hoping for more information from the KB entry which however does not seem to exist. Question following.

A: Title: FIX: Kernel does not properly handle BSPs that distinguish between L1 and L2 cache flushing in Windows Embedded CE 6.0.

Symptoms:
A performance problem was found in Cortex-A8 based processors due to excessive PSL API call overhead caused by unnecessary L2 cache flush operations.

With the code changes included in this QFE, the kernel now maintains proper L2 cache coherence so that the system can benefit from performance enhancements obtained by separating L1/L2 cache flushing in the OAL. To take advantage of this performance improvement, the OAL should be modified to flush L1 and L2 cache only when necessary.

This QFE may also address L2 caching issues in other CPU architectures whose OEMCacheRangeFlush implementations properly respect L2 cache flags:
• CACHE_SYNC_WRITEBACK: write back L1 data cache to L2 data cache
• CACHE_SYNC_DISCARD: write back L1 data cache to L2 data cache and discard L1 data cache
• CACHE_SYNC_L2_WRITEBACK: write back L2 data cache to memory
• CACHE_SYNC_L2_DISCARD: write

msft_davbo (Moderator)[12:56]:

Q: [32] Multiple Displays: One of our projects requires two displays with independent content. Under CE6 is it possible using direct show to display different media (ie. different videos) on each of the display and two channels of Audio? We will write custom app.

A: Check out Microsoft Embedded Automotive who has support for up to 10 zones of AV content: http://www.microsoft.com/auto/ma.mspx. Typically they are just using 1-2 zones for front and rear AV zone control in the vehicle.

Sing Wee [MS] (Expert)[12:57]:

Q: [31] Can you point me to the KB entry or tell us what exactly has to be adapted in the OAL Cache routine?

A: Damian, can you please send me your email in a private message? I'll see if I can dig up the KB number for you.

Sing Wee [MS] (Expert)[12:58]:

Q: [31] Can you point me to the KB entry or tell us what exactly has to be adapted in the OAL Cache routine?

A: Looks like there was a limit to how much I could put in my response. Here's the final line in it's entirety:
• CACHE_SYNC_L2_DISCARD: write back L2 data cache to memory and discard L2 data cache

Travis Hobrla [MS] (Expert)[12:59]:

Q: [35] Travis [33] i am integrating lint, doxygen and some other tools (see previous question about build marker). so there are some non standard files to clean

A: I see. Well, the clean rules in makefile.def are pretty straightforward, so you should be able to alter them without affecting too much. I'd recommend adding a 'cleanlint' target to the clean rule, and implementing that.

ks [MS] (Expert)[12:59]:

Q: [31] Can you point me to the KB entry or tell us what exactly has to be adapted in the OAL Cache routine?

A: Basically, the OAL's OEMCacheRangeFlush implmentation needs to follow the guideline in http://msdn.microsoft.com/en-us/library/ee478186.aspx

msft_davbo (Moderator)[13:00]: Hello everyone, we are just about out of time.

Thank you for joining us for our Windows Embedded CE 6.0 chat today!

<http://www.Microsoft.com/Embedded>;

A special thank you to the product group members for coming out.

The transcript of today’s chat will be posted online as soon as possible, to <http://msdn.microsoft.com/en-us/chats>;. We’ll see you again for another chat next month. Please check <http://msdn.microsoft.com/en-us/chats>; for the list of upcoming chats.

If you still have unanswered questions, let me suggest that you post them on one of our newsgroups on
<http://msdn.microsoft.com/en-us/windowsembedded/ce/default.aspx>

-Windows Embedded CE 6.0 R3 Now Available! <http://msdn.microsoft.com/windowsembedded/ce/dd630616.aspx>;

The Questions

msft_davbo (Moderator)[12:05]: Chat is now started.

Andrew Scholan MCTS[12:05]: Hello, this is Andrew Scholan from Plextek in Cambridge, UK.

wolfelectronic[12:06] asked the experts: hi experts, is there any way to provide debug information for assembler files (.s) to the debugger so that i can step through the sources? currently only exported symbols are visible to the debugger

wolfelectronic[12:09] asked the experts: hi experts, i have integrated lint in the build prrocess. to see the output i have used the build_markers for C files, so they are also shown as c files in the summary. is there any way to show them with the "other files", in other words which build marker

wolfelectronic[12:09] asked the experts: should i use for other files?

Sebastien[12:11] asked the experts: Hello everyone, I am currently testing my WinCE 6 iMX31 based platform and doing automated suspend/resume stress testing. My application first sends a message to a PIC to ask the PIC to resume the processor later, then my application goes to suspend.

Sebastien[12:12] asked the experts: After ten seconds, the PIC wakes up the system and the process repeats.

wolfelectronic[12:12] asked the experts: [1] so there is no way to get debug info for assembler files into the pdb files?

Sebastien[12:12] asked the experts: After making this work properly, I added a thread in my test application which does nothing more than opening a file and closing it in a loop.

Sebastien[12:12] asked the experts: After a few suspend/resumes, a message box appears in CE telling me that the program memory is very low and the system becomes unresponsive.

Sebastien[12:12] asked the experts: When I'm not executing this thread, my system can suspend/resume up to a thousand times or more.

Sebastien[12:13] asked the experts: I'm creating the file in RAMFS, and I don't believe my thread can have any leak considering it's just opening and closing the same file. Do you have any idea what could go wrong ? Thank you.

wolfelectronic[12:15] asked the experts: [6] i know i can step i the disassembler view, but it is somewhat painful without the coments of the sourcefile. So I would like to see and step in the assembler sourcefile while debugging like when debugging c or cpp files

wolfelectronic[12:16] asked the experts: [6] also local (not exported] labels are not known to the debugger

wolfelectronic[12:17] asked the experts: [11] well thats the way i spend most of my time

Bruce Eitman[12:17]: Sebastian - does your question have anything to do with the suspend/resume? What happens if you just run your file access thread without suspending?

wolfelectronic[12:18] asked the experts: [12] ok, thankyou kurtken

Andrew Scholan MCTS[12:19] asked the experts: XAML + Other Windows: I have an MFC app which contains window based user draw controls (caches and draws bitmaps and overlays data on them). I want to update the UI to use XAML. How can I embed some of these existing controls in the XAML app?

Andrew Scholan MCTS[12:22] asked the experts: XAML + Other Windows: Effectively I want to skin the current app using XAML. Maybe there are some examples shipped with R3?

wolfelectronic[12:23] asked the experts: hi experts, is there a way to put additional items to the clean target without modifying makefile.def?

Sebastien[12:23]: Bruce: sorry I didn't see you message until now. If I don't suspend/resume, I don't have this problem

winceLover[12:26]: hi experts, is there an easy way to enable debug zones in advance for dlls that hasn't been loaded yet? Some dlls only get loaded while an application is running and by the time I get to click on Target->CE Debug Zones-><module name> it's already too late

PaulT[12:27]: winceLover: Don't forget to check the Ask the Experts checkbox. This puts your question in a queue from which it is answered...

winceLover[12:28] asked the experts: hi experts, is there an easy way to enable debug zones in advance for dlls that haven't been loaded yet? Some dlls only get loaded while an application is running and by the time I get to click on Target->CE Debug Zones-><module name> it's already too late

wolfelectronic[12:29] asked the experts: Sing Wee [13] well that doesn't work for assembler files, at least in my environment, although I have to say I use trace32 vom lauterbach most of the time. But this is the behaviour i would wish for .s files.

Sebastien[12:30] asked the experts: [10] - I will try to track the memory used in my thread more thoroughly. It's too bad I can't use KITL at that point as I'm doing suspend/resumes tests. So Travis, you're saying that there might be a leak in the RAM file system (which is public code) ?

Andrew Scholan MCTS[12:31]: XAML + Other Windows: Thanks.

Sebastien[12:32] asked the experts: What is the best way to setup a filesystem storing hive registry ? In our system, the SD card will be the storage holding it. Should we setup the SD card as MountPermanent, and are there other registry keys worth setting ?

Prabu[12:33] asked the experts: We need to give camera data to the appln for displaying it on the WINCE 6.0 device LCD or we need to send the camera frames to the device USB video class for displaying at the desktop PC app.IS both my requirement will be acheived by DSHOW camera driver?

Sebastien[12:33]: Thanks Travis

wolfelectronic[12:36] asked the experts: Sing Wee [19] well, perhaps there are not much assembler junkies out there , thank you any way

Prabu[12:37] asked the experts: Using DSHOW layer can we give the camera frames to the client UVC stack?

Sebastien[12:40]: [20] Sing Wee : I haven't tried using AppVerifier, does it support well checking leaks while suspending/resuming the system ?

Prabu[12:41] asked the experts: USB Video Class

Sebastien[12:41] asked the experts: [20] Sing Wee : I haven't tried using AppVerifier, does it support well checking leaks while suspending/resuming the system ?

wolfelectronic[12:41] asked the experts: Sing Wee [23] i am doing CE6, porting to a OMAP platform, currently working on the bootloader, but work is proceeded to jump to BootloaderMain

Sebastien[12:43] asked the experts: [21] - yes, this is setup correctly and works fine, until going to suspend/resume, where the SD gets unmounted and remounted. My question is : should we absolutely keep the power on to the SD card (it's never removed), and set it as MountPermanent ?

Damian Barnett[12:46] asked the experts: In a previous QFE adressing the L2 cache it is documented that one has to adapt the OAL Cache routines. To found out how we were hoping for more information from the KB entry which however does not seem to exist. Question following.

wolfelectronic[12:46] asked the experts: Travis [17] I am not sure if i understand you right, the WINCETARGETFILES targets are executed after building so not really good for cleaning, WINCETARGETFILE0 are executed before compiling, but what if only the clean target is performed?

Damian Barnett[12:47]: Can you point me to the KB entry or tell us what has to be adapted in OAL Cache routine?

Damian Barnett[12:47] asked the experts: Can you point me to the KB entry or tell us what exactly has to be adapted in the OAL Cache routine?

Sebastien[12:49]: [26] Thank you Sing

Andrew Scholan MCTS[12:51] asked the experts: Multiple Displays: One of our projects requires two displays with independent content. Under CE6 is it possible using direct show to display different media (ie. different videos) on each of the display and two channels of Audio? We will write custom app.

Sebastien[12:51]: [28] - Thank you Travis

wolfelectronic[12:51] asked the experts: Travis [17] yes, for example, or clicking Build - Clean in VS2005

wolfelectronic[12:55] asked the experts: Travis [33] ok, are there "best practices" for modifying makefile.def?

wolfelectronic[12:57] asked the experts: Travis [33] i am integrating lint, doxygen and some other tools (see previous question about build marker). so there are some non standard files to clean

Damian Barnett[12:59]: Thanks Sing!

Chat Topic: Open Peer-to-Peer Technical Chat in Progress

Platform Builder: Cleaning Non-Standard Files

2009-11-24T13:34:51-12:00:00

During today’s chat with Microsoft’s Windows CE Team, someone asked “is there a way to put additional items to the clean target without modifying makefile.def?” So I decided to see if I could come up with a way.

It can’t be done using a sources file. Sources files are only used to set environment variable prior to nmake being called and we need a target named “clean” to handle cleaning the additional files.

That leaves makefile.inc and makefile. I tried it in makefile.inc with a WINCETARGETFILES set for a different target than clean. It didn’t work.

I added a clean as a target in the makefile after including makefile.def, that didn’t work either. On a whim, I put it before including makefile.def and it worked. The following is my test makefile.

clean:

-@del /q file.txt

!INCLUDE $(_MAKEENVROOT)\makefile.def

This successfully deletes file.txt and the clean target in makefile.def is still functioning to clean obj and cod files.

An alternative to this would be to create your own makefile.def and include it. For this, I put a makefile.def in the root of my platform (_TARGETPLATROOT) which is an exact copy of the makefile above. Then I modified my makefile to be:

!INCLUDE $(_TARGETPLATROOT)\makefile.def

This method allow me to have a common makefile.def for my platform which will make maintenance easier in the future.

Windows CE Chat November 24, 2009

2009-11-23T06:01:45-12:00:00

Another great opportunity to ask Microsoft engineers your technical questions is coming up on Tuesday, November 24th. These chats are your opportunity to get advice and answers from the engineers at Microsoft. You may want to review the transcript from previous monthsto get an idea about what kind of topics are discussed.

Title: Windows CE Live Chat

When: Tuesday, November 24, 2009 9:00 - 10:00 A.M. Pacific Time

Add to Calendar

Description: Do you have tough technical questions regarding Windows CE or Windows Mobile for which you're seeking answers? Do you want to tap into the deep knowledge of the talented Microsoft Embedded Devices Group members? If so, please join us for a live Windows CE chat and bring on the questions! Windows CE is the operating system that is powering the next generation of 32-bit, small-footprint and mobile devices. This chat will cover the tools and technologies used to develop devices using the Windows CE operating system.

To join this chat, please log on via the main MSDN chat page at: http://msdn.microsoft.com/chats/

Join the chat room on the day of the chat: www.microsoft.com/communities/chats/chatrooms/msdn.aspx

Windows CE: Using RAPI to Run Applications (Part 2)

2009-10-30T15:24:04-12:00:00

The CERunApp application can be downloaded from:

Download CERunApp.exe

The CERunApp source code can be downloaded from:

Download CERunApp source code

In Windows CE: Using RAPI to Run Applications (Part 1) I wrote about starting this project to create a copy of the Windows Mobile Developer Power Toys application RAPIStart. In this article I will continue by creating an slight twist on RAPIStart.

As I discussed in Part 1, I decided that simply reproducing RAPIStart wasn’t all that exciting, since the source code for a similar app is available in the Windows Mobile SDK. So in this article I will develop a GUI based application that not only starts an app on a Windows CE device from a connected workstation, but will also transfer the app to the device before running it. I will show the interesting code here, but the link at the top of this page leads you to the download of the code and the app itself.

Since this is a GUI based app, I developed it using C#. This choice meant that I spent very little effort on the GUI and was able to focus on the RAPI pieces.

The user interface looks like this:

This simple dialog contains:

1. A text box to enter the application to run on the Windows CE device

2. A browse button that opens a System.Windows.Forms.OpenFileDialog to select a file

3. A text box to enter command line options

4. A button to request that the app be downloaded to and run on the Windows CE device

Simple enough, and it requires very little code to back it up if we ignore the RAPI bits. Basically there are two functions, one each for the buttons. That code is:

private void FileBrowseButton_Click(object sender, EventArgs e)

{

if (DialogResult.OK == openFileDialog1.ShowDialog())

{

AppName.Text = openFileDialog1.FileName;

}

private void RunApplicationButton_Click(object sender, EventArgs e)

{

CRapi RAPI = new CRapi();

if(RAPI.CeCopyToDevice(AppName.Text, "\\" + openFileDialog1.SafeFileName))

RAPI.CeRunApplication("\\" + openFileDialog1.SafeFileName, CommandLineOptions.Text);

else

System.Windows.Forms.MessageBox.Show("Unable to copy file to the Windows CE");

}

The browse button handler, FileBrowseButton_Click(), simply calls on the OpenFileDialog class to show the dialog. If it succeeds, then fill in the text box with the file path and name.

The run applciation handler, RunApplicationButton_Click() uses a CRapi class that I will show next to copy the file to the Windows CE Device and then start the application.

The CRapi class is the meat of this application. It knows how to make a connection to the Windows CE device and then uses the connection to perform actions. To make a connection, I ported the code from the MSDN documentation for CeRapiInitEx(). The MSDN example includes a function named TryRapiConnect()which attempts to make a connection to the device. The ported code is:

// Code from MSDN

// Copied from C++ examle and converted to C#

private uint TryRapiConnect(uint dwTimeOut)

{

uint hr = E_FAIL;

bool fInitialized = false;

RAPIINIT riCopy = new RAPIINIT();

riCopy.cbsize = Marshal.SizeOf(riCopy);

hr = CeRapiInitEx(ref riCopy);

if (SUCCEEDED(hr))

{

uint dwRapiInit = 0;

fInitialized = true;

dwRapiInit = WaitForSingleObject(

riCopy.heRapiInit,

dwTimeOut);

if (WAIT_OBJECT_0 == dwRapiInit)

{

// heRapiInit signaled:

// set return error code to return value of RAPI Init function

hr = riCopy.hrRapiInit;

}

else if (WAIT_TIMEOUT == dwRapiInit)

{

// timed out: device is probably not connected

// or not responding

hr = ERROR_TIMEOUT;

}

else

{

// WaitForSingleObject failed

hr = (uint)Marshal.GetLastWin32Error();

}

if (fInitialized && FAILED(hr))

{

CeRapiUninit();

}

if (!fInitialized || FAILED(hr))

System.Windows.Forms.MessageBox.Show("Windows CE device does not appear to be connected");

return hr;

}

This function is a attempts to make a connection. It may not be able to because it either times out or an error occurs.

The code for copying the file uses the System.IO.BinaryReader class to read the application on the device and copies it to the device using CeCreateFile() and CeWriteFile().

public bool CeCopyToDevice(string AppName, string FileName)

{

bool ReturnValue = false;

uint RapiResult;

if (!File.Exists(AppName))

return false;

RapiResult = TryRapiConnect(5000);

if (SUCCEEDED(RapiResult))

{

BinaryReader DTFile =

new BinaryReader(File.Open(AppName, FileMode.Open));

System.IntPtr RemoteFile = CeCreateFile(FileName, GENERIC_READ | GENERIC_WRITE, 0, 0, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, 0);

try

{

byte[] Buffer = new byte[1024];

bool Done = false;

int BytesWritten;

int BytesRead;

while (!Done)

{

BytesRead = DTFile.Read(Buffer, 0, 1024);

if (BytesRead == 0)

Done = true;

else

{

CeWriteFile(RemoteFile, Buffer, BytesRead, out BytesWritten, 0);

}

ReturnValue = true;

}

finally

{

CeCloseHandle(RemoteFile);

DTFile.Close();

}

CeRapiUninit();

}

return ReturnValue;

}

You will notice that I chose to call TryRapiConnect()from this function rather than from the CRapi constructor. I can’t say that it is absolutely the right choice, but I did it because I didn’t want to hold the connection open any longer than necessary. ActiveSync connects can come and go, so my thinking here is the minimize the risk of lost connecting by just having it open when it is being used. This choice means that the code will need to open it again to start the application.

CeRunApplication()is used to start the application on the device. This function also calls TryRapiConnect()to make the connection, then uses CeCreateProcess() to start the application and pass in the command line parameters.

public bool CeRunApplication(string AppName, string CommandLine)

{

bool ReturnValue = true;

uint RapiResult;

RapiResult = TryRapiConnect(5000);

if (SUCCEEDED(RapiResult))

{

PROCESS_INFORMATION pi = new PROCESS_INFORMATION();

if(CeCreateProcess(AppName, CommandLine, IntPtr.Zero, IntPtr.Zero, false, 0, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, ref pi))

{

CeCloseHandle(pi.hProcess);

CeCloseHandle(pi.hThread);

}

else

{

System.Windows.Forms.MessageBox.Show("Failed to start application. Errorcode = " + CeGetLastError());

}

CeRapiUninit();

}

return ReturnValue;

}

That’s it, well not completely because there are some supporting functions, data and structures. The rest of the code can be found in the code download at the top of this page.

This app does have some downsides. To use it to run an app on the device, the app must be on your workstation and must be downloaded first. As you can see in the picture of the dialog, I used it to run ipconfig within cmd.exe. Cmd.exe had to be downloaded. The workaround for this is to use RAPIStart, or one of you enterprising developers may want to extend this to select an application that exists on the device instead of the workstation.

NOTE

There seems to be some question about how to run this application. If you download the executable file, you will run it on your Windows XP/Vista/7 computer. To do so, you will need the .NET Framework 2.0 or newer and have ActiveSync running and connected to your device.

If you download the source, you can of course change the .NET Framework version, but you will still run the app on your Windows XP/Vista/7 computer.

Windows CE: Using RAPI to Run Applications (Part 1)

2009-10-29T14:48:48-12:00:00

A few months ago I downloaded the Windows Mobile Developer Power Toys (Download details: Windows Mobile Developer Power Toys) because I had a need for CERDISP, the Windows CE Remote Display tool. At that time, I looked around at the other tools that were installed and played with RAPIStart.exe. RAPIStart.exe is a command line tool that lets you start applications on your device from your workstation using ActiveSync. A handy little tool, so I made a note to try to reproduce it and write a little about RAPI.

I finally got to that point on my list and started writing my version of RAPIStart. Did a little research and started writing a command line tool using C. My research told me that to start an app on the device from a workstation I would need to call CeCreateProcess(). To call CeCreateProcess() we first need to call CeRapiInit() or CeRapiInitEx() to establish a connection to the device.

My research also told me that CeRapiInit() has a tendency to hang if the connection isn’t established, but CeRapiInitEx() is a little friendlier to use because it times out. MSDN even has some sample code for establishing the connection, so I used it. The example function is TryRapiConnect() and since it is available on MSDN, I won’t reproduce it here.

So I created a Visual Studio command line application project and pasted TryRapiConnect() into the file and called it from _tmain(). Being impatient, I tried to compile knowing that I hadn’t done anything to ensure that it compiles like including rapi.h. or set it to link with rapi.h. So it failed. Now the adventure begins. Where do I get rapi.h and rapi.lib. A little searching on my hard disk and I found rapi.h in the Platform Builder files, but no rapi.lib. I thought that it must be available someplace other than the Windows Mobile SDK, but I didn’t find it anyplace else, so I downloaded the SDK and installed it. Then set the includes and lib paths correctly and it builds.

The next step is to create a little test to start a hardcoded application, in this case my registry editor from Windows CE: Simple Little Registry Editor. Here is the code:

int _tmain(int argc, _TCHAR* argv[])

{

HRESULT hr;

PROCESS_INFORMATION pi;

hr = TryRapiConnect(5000);

if( SUCCEEDED(hr) )

{

if (!CeCreateProcess(_T("regedit.exe"), NULL, NULL, NULL, FALSE, 0, NULL, NULL, NULL, &pi))

{

_tprintf( TEXT("Failed to start application (%d)\n"), CeGetLastError());

}

else

{

CeCloseHandle( pi.hProcess);

CeCloseHandle( pi.hThread);

}

CeRapiUninit();

}

return 0;

}

Simple enough and it starts my registry editor when it runs. The next step is to handle the command line arguments for the application name and parameters.

But wait a minute, why am I wasting time developing a command line tool? Did I mention that the source code for a similar tool is available in the Windows Mobile SDK? Why start an app that is already on the device, RAPIStart does that already?

Why write a blog about this? Well it answers a few questions on how to get started, and it shows some C code for using RAPI.

Next step, write a C# GUI app – See Part 2 at Windows CE: Using RAPI to Run Applications (Part 2)

Windows CE Chat Transcript (October 27, 2009)

2009-10-27T13:02:51-12:00:00

Answers from Microsoft:

KarelD_MSFT (Expert)[2009-10-27 11:58]: Karel Danihelka - Developer in Partner Response Team.

davbo_msft (Moderator)[2009-10-27 11:59]: Our chat today covers the topic of Windows Embedded CE & Windows Mobile!

1. This chat will last for one hour. During this hour, our Experts will respond to as many questions as they can. Please understand that there may be some questions we cannot respond to due to lack of information or because the information is not yet public.

2. We encourage you to submit questions for our Experts. To do so, type your questions in the send box, select the “ask the Experts” box and click SEND. Questions sent directly to the Guest Chat room will not be answered by the Experts, but we encourage other community members to assist.

3. We ask that you stay on topic for the duration of the chat. This helps the Guests and Experts follow the conversation more easily. We invite you to ask off topic questions after this chat is over, but not during.

4. Please abide by the Chat Code of Conduct.
Chat code of conduct: <http://msdn.microsoft.com/chats/chatroom.aspx?ctl=hlp#Conduct><BR< a>>

davbo_msft (Moderator)[2009-10-27 11:59]: We are pleased to welcome our Experts for today’s chat. I will have them introduce themselves now.

Sing Wee[MS] (Expert)[2009-10-27 12:0]: Hi, I'm Sing Wee, part of the CoreOS/BSP Test Team.

rajran[MS] (Expert)[2009-10-27 12:1]: Hi , I am Rajeev Rangappa, PM in CoreOS team.

RajeevDubey[MS] (Expert)[2009-10-27 12:3]: Hi, I am Rajeev Dubey, Bluetooth Program Manager.

MariNe_MSFT (Expert)[2009-10-27 12:3]: My name is Mariana Nenova - SDET in the Shell team.

MikeThom [MS] (Expert)[2009-10-27 12:3]: Hi I am Mike Thomson, Group Manager from Windows Embedded CE

Sue Loh [MS] (Moderator)[2009-10-27 12:3]: Hi, I'm Sue Loh, a developer on the Windows Mobile tools team (with past experience on the kernel and file system). I hope we can answer some of your questions today!

FBLANQ_MSFT (Expert)[2009-10-27 12:3]: Hi, I'm Francisco Blanquicet, part of the CoreOS/BSP team.

mskim_MS (Expert)[2009-10-27 12:4]:

Q: Regarding Silverlight Runtime in R3 and Expression Blend 2 - Expression Blend 2 appears to be unable to cope with the CacheMode="BitmapCache" tag that's needed for off-screen rendering in the silverlight runtime. Am I doing something wrong?

A: Andrew, CacheMode is from Silverlight3, we added this feature into Cashemere for a better performance but Expression Blend2 doesn't know about this SL3 property.

GLanger_MS (Expert)[2009-10-27 12:5]: Hi, I'm Glen Langer, lead PM for Core and BSPs.

kurtken_msft (Expert)[2009-10-27 12:6]:

Q: Can you point me to any documentation on the "threaded" SMS-message view in tmail.exe; I am having trouble adding my custom context-menu extension to it

A: Are your referring to the Windows Mobile SMS application? This chat is for Windows CE.

MS_Dinglu (Expert)[2009-10-27 12:7]: Hi, I am Dingding Lu, I am in CoreOS/BSP test team

mskim_MS (Expert)[2009-10-27 12:7]:

Q: So if I use Blend 3 will this help or just cause more problems?

A: You can't use Expression 3 with Cashmere, please use Blend2. You will need to add CacheMode only for the device XAML not in Blend2 XAML.

kurtken_msft (Expert)[2009-10-27 12:8]:

Q: Regarding mdd/pdd flash driver. There is some blocks that the MDD allocates for managing the data. Is it save to backup and recover those blocks? Where can we get info about them?

A: Can you give more information on what it is you are trying to do? The MDD's management of blocks is opaque because if it ever changes the only updates will be internal. is there a reason you need to access the internal structures?

Sue Loh [MS] (Moderator)[2009-10-27 12:8]:

Q: Hi! We are developing an app for a new handset running WM6.5 and are having problems when starting up first time. We are built into image and start up at boot since we have set correct reg keys in HKLM\Init. But one test case fails, namely to get reg notif

A: Can you explain a bit better what you mean by your test case fails to get reg notif? Who is supposed to change the registry key, when? Who is waiting on it, when?

kurtken_msft (Expert)[2009-10-27 12:9]:

A: Hi Simon. This chat is for windows CE, and does not cover windows Mobile. The best thing for you to do is contact your WM representative that licenses WM to you to get support.

MikeThom [MS] (Expert)[2009-10-27 12:9]:

Q: Does Wince6.0 R3 include iPOD support?

A: No. There is no integrated support in Windows Embedded CE. There is an automative kit that does supply support for head-units.