Windows Driver Foundation

Posted August 13, 2004

Chat Date: July 27, 2004

Please note: Portions of this transcript have been edited for clarity

Introduction

Moderator: AndyQ (Microsoft)
Welcome to today's MSDN chat. Our topic is Windows Driver Foundation. Questions, comments, and suggestions are welcome.

Moderator: AndyQ (Microsoft)
I'll now have the hosts introduce themselves.

Host: JohnR (Microsoft)
Hi, I am the Development Lead for Windows Driver Foundation, Kernel Mode. I also developed the I/O Queuing, locking, and baseline object model.

Host: Eliyas (Microsoft)
My name is Eliyas Yakub. I'm a software design engineer in the Windows Driver Foundation(Kernel Mode) team.

Host: Johan (Microsoft)
I'm a Program Manager with the Windows Device Experience Group (WDEG) responsible for the Windows Driver Foundation

Host: Nar (Microsoft)
Hi, I am Nar Ganapathy. I am the development manager for the Windows Driver Foundation team responsible for kernel and user mode frameworks, Prefast and other tools.

Host: Doron (Microsoft)
My name is Doron Holan, I am a developer in Windows Driver Foundation. My main responsibilities include pnp, power management, power policy, wmi, and i/o targets.

Host: Ravi (Microsoft)
Hi, I am Ravi Gollapudi. I am the test lead on the Windows Driver Foundation (Kernel Mode) team.

Start of Chat

Host: Johan (Microsoft)
We are still in the early stages of development for the UMDF, and hence little documentation has been made available externally.

Host: Nar (Microsoft)
Q: What functionality will be available with the User-mode framework? I don't recall seeing much documentation about the user-mode functionality. Any examples?
A: The user mode framework project is still in the early stages of design and implementation. Our goal is to enable drivers for most protocol bus based devices (USB, 1394, Bluetooth etc.) to be written in user mode. There is a WINHEC presentation (WDF-Introduction) that briefly describes the architecture of UMDF. The presentation should be available at https://www.microsoft.com/whdc

Host: Ravi (Microsoft)
Q: How stable is the WDF; ie is it too early to develop production drivers using the WDF?
A: WDF is stable enough to develop drivers and investigate at this point of time. It is not stable enough to ship, though.

Host: Johan (Microsoft)
Q: Is there a beta program, and how do I I sign up?
A: Go to https://Beta.Microsoft.com and log on using this special Guest Account (Guest ID: Guest4WDF) to access a nomination survey. Once you fill out the survey and your data is validated/approved you will be enrolled in the beta program.

Host: JohnR (Microsoft)
Q: Will there be any support for setting up a mapped DMA transfer fro bidirectional operation? Current API requires the developer to specify read or write. I would like to setup a single mapping that will stick around a while for reading AND... ...writin
A: Are you doing this today with WDM? If so, what API's are you using to accomplish this?

Host: Johan (Microsoft)
Q: Do I need the DDK to use WDF?
A: Yes you do. So if you enroll in the WDF Beta Program you will automatically be enrolled in the DDK program that is needed to support WDF.

Host: JohnR (Microsoft)
**Q:**Instead of using the DMA API, I am just getting the phys addr using MmGetPhysicalAddress. I know that won't work on all platforms (espeically moving forward) so I'd like to use the DMA API, but it doesn't support this functionality.
A: Yes, this won't work on all platforms, esp. ones with inward maps, and non-unity mappings between bus and logical addresses. Currently, WDF is focused on platform transparency, and works completely through the HAL API's. If we can better understand what you are trying to accomplish, we may be able to come up with some recommendations for you.

Host: Johan (Microsoft)
Q: May be this was already, asked but I am joining the chat late, sorry. When can we expect WDF to be released ? Currently I had to develop an in-house WDF replacement for a simple driver which I wrote with WDF and we have to ship.
A: That date has not yet been made public at this time, however preliminary dates have been made available through the beta program. I would encourage you to join the beta program to stay up to date on the latest WDF developments.

Host: JohnR (Microsoft)
Q: Actually, that's not quite accurate. I was doing that in a previous version. Now I allocate physical pages only with MmAllocatePagesForMdl and sort them so that they are physically contiguous. I then use the PFN to form the phys addr.
A: We need to drill down on what you are trying to accomplish, and the current technique to see if the pattern makes sense for base WDF functionality. As I mentioned, WDF must offer abstractions that fit within the currently defined WDM model for mapped memory and the HAL.

Host: Johan (Microsoft)
Q: I am in the beta program, damn it, and am not aware of any date ...
A: This was posted earlier today.

Host: Johan (Microsoft)
Q: I am looking at the newsgroup and the beta site - I can't find any date. Please, give me at least some indication - this year, next year?
A: microsoft.beta.windows.driverfoundation.announcements

Host: Nar (Microsoft)
Q: I am looking at the newsgroup and the beta site - I can't find any date. Please, give me at least some indication - this year, next year?
A: We can't post a date in the chat room as we are only allowed to reveal this date to customers who have agreed to an NDA. As a valued beta customer you can get this information from the beta newsgroup.If you have not seen the posting, you will see it soon.

Host: Johan (Microsoft)
Q: Will the source be made available at the release?
A: MS is considering making source code available in the interest of raising the level of understanding of the inner workings of WDF. While there has not been a final decision on this, it is a topic dear to our heart which we continue to pursue.

Host: Johan (Microsoft)
Q: Last year MS announced the Windows Driver Framework. How is that different from the Windows Driver Foundation?
A: The Windows Driver Framework was the name for what is now the Kernel-Mode Driver Framework portion of the Windows Driver Foundation. The Windows Driver Foundation includes the Kernel-Mode Driver Framework, the User-Mode Driver Framework and validation tools such as PREFast for Drivers.

Moderator: AndyQ (Microsoft)
For the duration of this event chat, we ask that all text posted in this room remain on topic (Windows Driver Foundation). We welcome you to stick around after to discuss other topics.

Host: Johan (Microsoft)
Q: What is the OS that WDF will be available for?
A: The Kernel-Mode Driver Framework will be available for platforms from Win2K onward.

Host: Eliyas (Microsoft)
Q: What sort of drivers can I write with WDF today?
A: Generic WDM function and filter drivers, ndis-wdm miniports, ndis protocol drivers, non-pnp drivers, USB client drivers, monotlithic storage drivers, 1394 client drivers, smartcard drivers.

Host: Johan (Microsoft)
Q: Do I need to know WDM in order to use WDF?
A: While WDF simplifies and abstracts the driver concepts, some understanding of the underlying concepts is necessary.

Host: Eliyas (Microsoft)
Eliyas_MS: Smartcard drivers may not be supported in the first version. Generic drivers for PCI, PCMCIA, ISAPNP, etc can also be written using framework.

Host: Doron (Microsoft)
Q: Anything special in WDF for bus drivers?
A: Yes, WDF has alot of functionality that makes building a bus driver much easier then before.

Moderator: AndyQ (Microsoft)
Well it's time for us to go now, sorry if we missed your question.

Moderator: AndyQ (Microsoft)
Thanks for joining us today and thanks for the questions. You'll be able to find the transcript of this chat soon at https://msdn.microsoft.com/chats/. Please see the chats schedule for upcoming topics.

Moderator: AndyQ (Microsoft)
you can find more information about upcoming chats at: https://www.microsoft.com/communities/chats/default.mspx and https://msdn.microsoft.com/chats/

Moderator: AndyQ (Microsoft)
Thanks!

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