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RE: Question about output data streaming
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RE: Question about output data streaming


  • Subject: RE: Question about output data streaming
  • From: "David Tan" <email@hidden>
  • Date: Thu, 8 Jan 2009 14:21:51 +0800

Hi Jeff,

 

Thanks for your confirmation!

 

The reason why I asked this question is that: After calling Float32ToNativeInt32(), I cannot see continuous integer in the conversion result. The result seems very discrete and I cannot see any pattern.

Do you have any idea of it?

 

Here I want to ask another question:

 

I’m working on a FireWire audio driver and have some source code of a user-mode driver. I inherited most of the logic of the DCL program from the user-mode driver. However I often encountered odd issues while debugging the kernel driver. Some pointer variables will be changed to obvious protected memory (e.g. 0x01, 0x40) and calling these pointers again will cause the OS panic. However, I don’t there’s any code to change them to such odd address.

 

The only clue I can get now is that:

To setup DCL program, the user-mode driver will allocate some memory about 200 pages (4096 bytes / page). I’m not sure if it’s too big for kernel memory. If the kernel doesn’t like such a large memory allocation, it might be a mess while it does some memory duplication. And that’s why some pointer variables will get weird address. I’m suspicious of it because the fist allocation of 200 pages seems OK, but the second time always fails.

 

Could you give me some clarification about it? Thanks a lot!

 

Sincerely yours,

David Tan

Dextrys Co., Ltd.

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