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Windows XP Embedded Chat: EWF and El-Torito

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Posted August 25, 2003

Chat Date: August 7, 2003

Chat Participants:

  • Mike Hall, Product Manager in the Embedded Devices Group
  • Andy Allred, Software Tester in the Embedded Devices Group
  • Bill Moxley, Software Design Engineer on the Embedded Enabling Features (EEF) test team
  • Anil Ingle, Development Manager in the Embedded Devices Group
  • Lynda Allen, Test Engineer for Component Integration in the Embedded Devices Group
  • Ravi Gopal, Product Manager, Windows XP Embedded
  • Dan Simpson, Windows XP Embedded Documentation team
  • James Tallman, Software Test Engineer on Windows XP Embedded focused on EEFs

Moderator: Mikefos (Microsoft)
Welcome to today's Chat. Our topic is Windows XP Embedded, focusing on Enhanced Write Filter (EWF) and El-Torito. Questions, comments, and suggestions are welcome.

Moderator: Mikefos (Microsoft)
Let’s introduce our hosts for today.

Host: Mikehall (Microsoft)
Hi, I'm Mike Hall, a Product Manager in the Embedded Devices Group

Host: Andy (Microsoft)
Andy Allred - Software Tester for Windows Embedded

Host: Bill (Microsoft)
Hi, I’m Bill, I’m a Software Design Engineer on the Embedded Enabling Features (EEF) test team.

Host: Anil (Microsoft)
Hi, I'm Anil, Development Manager for Windows Embedded.

Host: Lynda (Microsoft)
Lynda Allen, Test Engineer for Component Integration

Host: Ravi (Microsoft)
Ravi Gopal -- Product Manager, XP Embedded

Host: dansimp (Microsoft)
Dan Simpson, XPE Documentation

Host: JamesT (Microsoft)
Hello, my name is James Tallman. I am a Software Test Engineer on XP Embedded focused on EEFs.

Host: Stephen (Microsoft)
Program Manager - Windows Embedded Customer Strike Team

Moderator: Mikefos (Microsoft)
Welcome everyone, let’s get started!

Host: Jon (Microsoft)
Jon Fincher, Program Manager, Customer Strike Team

Moderator: Mikefos (Microsoft)
For those that posted questions earlier, if you could re-post them, I'd be appreciative. Many were posted before all of our hosts joined.

Host: Anil (Microsoft)
Q: Is it possible to use EWF with removable media which has more than one partition?
A: Yes. But you will have to find a way to report the removable media as non-removable. The problem here is that Windows will not recognize anything other than the first partition on removable media.

Host: dansimp (Microsoft)
Q: How much memory is recommended to user with an El Torito image (that has about 200 MB)? Is there a rule to calculate it?
A: Depends on the applications you want to run. EWF protects a volume at the sector level, so the *maximum* size of an overlay equals the size of the volume. A 200 MB volume would max out at a 200 MB RAM overlay. You can use less RAM, depending on how resource intensive your applications are. There isn't a straightforward rule of thumb as to how much RAM is require. Test the performance of your device with different RAM amounts to see what works best for you.

Moderator: Mikefos (Microsoft)
Q: I want to know is there any way to boot pre FBA image from read only medium and then to make fba to go in the hard disk overlay. Can this be done?
A: Anything pre-FBA must be from writable media.

Host: Lynda (Microsoft)
Q: When I prepare a component for any special applications, I include the files and registries, but I had to go in to each file and give source path of file. I had one component from web and there source path was not given and it was working fine. If I don’t include the source path for files, it gives error while building. Any ideas?
A: You need to include all the files your component needs in a repository that gets imported into your Database Manager along with your component.

Host: Anil (Microsoft)
Q: Is it possible to make an EL Torito-based XPE image?
A: Short Answer Yes. You can change the shell (i.e. use any program as a shell) for any embedded image. IT would help if you could provide more details on what you are trying to do.

Host: Andy (Microsoft)
Q: Are there any plans from MS to open documentation on CMI, CMI Explorer ?
A: As for CMI documentation, there is no immediate plan to supply this, however I'll forward your request to be considered. With respect to CMI Explorer, there is extensive help via comments within the WSF, please take a look at it. If you need more help with the explorer wsf, please ask us in the newsgroup.

Host: Anil (Microsoft)
Q: I want to know is there any way to boot pre FBA image from read only medium and then to make FBA to go in the hard disk overlay. Are there any plans to make EWF support disk overlays before FBA start executing?
A: Not at the present time. Could you post more details as to why you need this?

Host: Ravi (Microsoft)
Q: Any plans for an MSDE component?
A: We are working on this but unfortunately we have no ETA.

Host: Mikehall (Microsoft)
Q: Anybody knows how to redirect a portion of the registry to another drive? And, of course, how to say to XPE to read from there at the boot time?
A: Tools such as Regmon from https://www.sysinternals.com monitor changes to the registry real-time, you could use the same techniques to monitor changes to the registry, hive this to a file on a net share or other drive - you will need to look at when the calibration information read back from the registry ? - you would need to load your registry hook before the driver loaded it's calibration data.

Host: Mikehall (Microsoft)
Q: This is my problem, I already know the registry changes that calibration do, but I don’t know how to load this from a hive before the ELO driver load in the boot time. Any suggestions?
A: Windows has 4 distinct load phases,

  1. Kernel load,

  2. Kernel Initialization (loads drivers),

  3. Services load,

  4. Win32 Subsystem load

Any registry load mechanism you create would need to load the registry information before the touch driver gets loaded - perhaps a small dummy driver might be the solution.

Host: Mikehall (Microsoft)
Q: But, I believe that this is not the best solution ... Probably, the ELO Developers will have to change their driver to predict this.
A: The O/S registry will need to be loaded for the ELO driver to query it's touch calibration information - drivers get loaded before applications, so you cannot write an application to read/write the information to the registry, the only other option is to create a dummy driver that loads the registry information for you.

Host: Bill (Microsoft)
Q: Is there any fix (QFE plan) to known issue with Component Designer .reg import that looses spaces from registry paths?
A: Currently a fix is not in the works for that issue.

Host: Bill (Microsoft)
Q: I'm starting to work with an XPe image that is using El-Torito and residing in a Native Mode AD domain. This was addressed earlier this week in the newsgroup, and I wanted to bring it up again. Since 2000/2003 server is constantly changing the access token to connect to network shares is there a workaround that you guys can see?
A: No we do not have a workaround on this issue yet. The problem is that we will loose the token after every reboot.

Host: Anil (Microsoft)
Q: Is there a tutorial/white paper on creating a bootable WINPE CD with custom network drivers?
A: Searching Google Groups I found this https://groups.google.com/groups?q=WINPE\&hl=en\&lr=\&ie=UTF-8\&oe=UTF-8\&selm=ezMiYn47CHA.2984%40TK2MSFTNGP11.phx.gbl\&rnum=2 (Note: this is not a Microsoft Posting).

Host: Lynda (Microsoft)
Q: We need to support at least two different chipsets. Does this mean that we must make and maintain two different builds or it there a simpler way, like to make few profiles in TD or to somehow build all drivers together?
A: You can include all the components for the two chipsets in one configuration by importing the PMQ's from both targets. HOWEVER, both chipsets need to use the same HAL. Otherwise it will create a conflict.

Host Guest_Saad_MS says:

Q: Is there a way to load everything from El Torito XPe and put it in RAM (like a RAM Drive), and after that everything will be load from RAM and not from CD ROM?
A: Yes, you can include the ramdisk driver in your runtime and use NTLDR ramdisk support to copy the image completely into RAM. Please post this question on the newsgroups and I'll post a detailed reply.

Host: Lynda (Microsoft)
Q: Thanks, i have already tried this and had a blue screen, but i will give it another try
A: What is the bug check you are seeing? Follow up with a post in the newsgroup where we can help you further.

Host: Bill (Microsoft)
Q: I only use WinPE when testing and making a xpe xonfig Any info on WinPE/Diskpart would be useful.
A: Diskpart can be useful for skipping the need for a 9x boot disk, and totally removes the need to run bootprep. The steps would be boot WinPE, run Diskpart to partition the drive, reboot into WinPE, format and deploy your image. No need for dos disks or bootprep.

Host: Ravi (Microsoft)
Q: Is there a way to have TD automatically retrieve the latest versions of MS components from the MS site (i.e. DX9, WMP9, Internet Explorer updates)
A: No. We have a tool called Device Update Agent (DUA) that you can use to update your already deployed images w/these features.

Host: Lynda (Microsoft)
Q: Lynda Did you get my question about Add & Remove programs not Removing Items from the Registry?
A: Yes, I did. I'm investigating the issue and will follow up with you in the newsgroup. Thanks for the question.

Host: Lynda (Microsoft)
Q: Is there any way to make one universal component for intel chipsets 845, 865, 875, and others for NVIDIA graphics cards.
A: Ideally it is best if each chipset is a separate component. If you wanted, you can then create a macro component that includes all the chipset components.

Host: Bill (Microsoft)
Q: if I have a need to boot XPe image from read-only CF, there is a couple solutions for that: EWF RAM-overlay or NTLDR ramboot. What solution would be better and less resources consumable? Is there any other solution for that in XPe?
A: It depends on your application, will you need to "commit" changes? If so then Ram based EWF.... More specifically you would want to use a ram_reg ewf.

Moderator: Mikefos (Microsoft)
Q: Any plans for a DirectX 9 component ? I don’t know if it is already done.
A: It is currently in process, but we don't have an ETA yet.

Host: Lynda (Microsoft)
Q: Is there a White paper or Tech Tip on how to add Printers to your Embedded image Correctly? When you use the Add Printer in CP it looks for HLP files and *.dlls in the /windows/I386 directory?
A: This is a known bug. The workaround is to manually add the necessary files to the runtime image. Not ideal, I know.

Host: Troy (Microsoft)
Q: Is there a way to setup EWF to always commit? Now, I must manually 'ewfmgr c: -commit", or do it programmatically every time I boot.
A: No. The best suggestion I have is to have a small program call the EWFAPI EwfMgrCommit on every startup of the computer. This could be done by as simply as adding ewfmgr c: -commit to the following key in the registry: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run

Host: Bill (Microsoft)
Q: Also, Mark wants to know if a CF being removable/non-removable can be marked by the OS, but I think this is strictly a hardware limitation right?
A: No, we cannot mark it via the OS. You have to use the Sandisk or other type utility to mark the media as non-removable.

Moderator: Mikefos (Microsoft)
Q: Is there a way to remove system restore points? Is there a way to completely disable system restore points? I don't have any system restore components included, but some utilities still create restore points in the System Volume Information director
A: We're not sure how to answer this. We'll try to get the most appropriate person for the question to respond in the newsgroup, if you can post it there.

Host: Jon (Microsoft)
Announcement: There are two important new security fixes available for XPE systems.

The first is MS03-026: Buffer Overrun in RPC Interface Could Allow Code Execution (823980), which can be downloaded from https://microsoft.com/downloads/details.aspx?FamilyId=D72D0867-953D-4293-90D3-B22849D07791&displaylang=en.

The second is MS03-023: Buffer Overrun in HTML Converter Could Allow Code Execution (823559), which can downloaded from https://microsoft.com/downloads/details.aspx?FamilyId=42C61BF7-408A-4E51-9601-B0DFBD539326&displaylang=en.

To install QFE's for XPE with SP1, you must first download and install Repository look-up may cause incorrect files to be copied (Q811279) from https://microsoft.com/downloads/details.aspx?FamilyId=5C1C0AE5-8285-4AB2-B753-C624C6B622DD&displaylang=en.

Host: Ravi (Microsoft)
Announcement: We will have a Windows XP Embedded webcast on EWF in October -- more details will be forthcoming on this over the next few weeks; please check the newsgroup, our website, or the DevWire newsletter for details. Bill Moxley, Software Design

Moderator: Mikefos (Microsoft)
Thanks for joining us today and thanks for the questions. It's time for us to go now.

For further information on this topic please visit the following:

Newsgroups: Mobile and embedded application development topics

Mobile and Embedded Transcripts: Read the archive

Website: Visit the Mobile & Embedded Developer Center

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