x64 File System Redirector

NTDEV
1

I have ported my kernel driver to the x64 platform and it is working fine.
The application, for now, will remain as a 32-bit app. The 32-bit app, and
the 64-bit driver, on the x64 platform are both working well. I have one
issue, however. The SDK states the following:

“The %systemroot%\System32 directory is reserved for 64-bit applications”
“Whenever a 32-bit application attempts to access %systemroot%\System32, the
access is redirected to a new directory, %systemroot%\SysWOW64”

My 32-bit app has a need to enumerate the drivers in the “true”
system32/drivers folder. The file system redirector doesn’t allow my app
access to this folder. In order to make this work, I would have to write a
64-bit app, have it retrieve the information, and pass it to my 32-bit app.
I can also think of several other methods to accomplish this.

It would be FAR easier for me to simply tell the OS that I am an x64 aware
32-bit app and to turn off the file system redirector for my process. Since
the file system redirector is only there to protect the OS from non-64-bit
aware apps, I was hoping there would be a method for me to let the OS know
that my 32-bit app is x64 aware.

I couldn’t find any such API in the Platform SDK. Is there any such method
available or planned prior to the x64 release? Thanks in advance.

Mike Berhan
busTRACE Technologies

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2

How about this API - Wow64EnableWow64FsRedirection() ?

http://msdn.microsoft.com/library/en-us/sysinfo/base/wow64EnableWow64FsRedir
ection.asp

Gary.

“Mike Berhan” wrote in message news:xxxxx@ntdev…
> I have ported my kernel driver to the x64 platform and it is working fine.
> The application, for now, will remain as a 32-bit app. The 32-bit app,
and
> the 64-bit driver, on the x64 platform are both working well. I have one
> issue, however. The SDK states the following:
>
> “The %systemroot%\System32 directory is reserved for 64-bit applications”
> “Whenever a 32-bit application attempts to access %systemroot%\System32,
the
> access is redirected to a new directory, %systemroot%\SysWOW64”
>
> My 32-bit app has a need to enumerate the drivers in the “true”
> system32/drivers folder. The file system redirector doesn’t allow my app
> access to this folder. In order to make this work, I would have to write
a
> 64-bit app, have it retrieve the information, and pass it to my 32-bit
app.
> I can also think of several other methods to accomplish this.
>
> It would be FAR easier for me to simply tell the OS that I am an x64 aware
> 32-bit app and to turn off the file system redirector for my process.
Since
> the file system redirector is only there to protect the OS from non-64-bit
> aware apps, I was hoping there would be a method for me to let the OS know
> that my 32-bit app is x64 aware.
>
> I couldn’t find any such API in the Platform SDK. Is there any such method
> available or planned prior to the x64 release? Thanks in advance.
>
> Mike Berhan
> busTRACE Technologies
>
> _________________________________________________________________
> Express yourself instantly with MSN Messenger! Download today - it’s FREE!
> http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
>
>
>

3

Thanks Gary. I thought it strange that I couldn’t find such an API. This
is going to save me some time :-).

Mike

----Original Message Follows----
From: “Gary”
Reply-To: “Windows System Software Devs Interest List”
To: “Windows System Software Devs Interest List”
Subject: Re:[ntdev] x64 File System Redirector
Date: Mon, 25 Oct 2004 14:02:07 -0400

How about this API - Wow64EnableWow64FsRedirection() ?

http://msdn.microsoft.com/library/en-us/sysinfo/base/wow64EnableWow64FsRedir
ection.asp

Gary.

_________________________________________________________________
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