Mail Archives: djgpp/1996/02/10/18:36:50
Xref: | news2.mv.net comp.os.msdos.djgpp:940
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From: | ulfg AT groundhog DOT phy DOT nist DOT gov (Ulf Griesmann)
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | how to allocate DMA pages ?
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Date: | 10 Feb 1996 20:59:53 GMT
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Organization: | NIST
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Lines: | 18
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Message-ID: | <4fj109$o5f@dove.nist.gov>
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NNTP-Posting-Host: | groundhog.phy.nist.gov
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Summary: | [Q] allocating DMA pages with DJGPP
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Keywords: | DMA pages and DJGPP
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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Hello All,
The 8237 DMA controllers in a PC can only perform DMA transfers to the
lower 16MB of physical memory. This makes it awkward to allocate
buffers for DMA transfers on machines with >16MB of memory because a
simple 'malloc' is no longer guaranteed to allocate DMAable memory.
Does anyone out there know of a good strategy for allocating DMA buffers
which works on large memory machines ? (Will take source code...)
Thank you,
Ulf
--
Ulf Griesmann \\\ Tel.: (301) 975 3212 (x73220)
National Institute of \\\ Fax.: (301) 990 1350
Standards & Technology \\\ e-mail:
Atomic Physics Division, Bld. 221/A167 \\\ ulfg AT groundhog DOT phy DOT nist DOT gov
Gaithersburg MD 20899, U.S.A. \\\ ulfg AT aeldata DOT phy DOT nist DOT gov
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