From:	Charles Sandmann <sandmann AT clio DOT rice DOT edu>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Using UDMA with DJGPP
Date:	Sun, 29 Jun 2003 16:49:54 CDT
Organization:	Rice University, Houston, TX
Lines:	12
Message-ID:	<3eff5f02.sandmann@clio.rice.edu>
References:	<000201c33b8e$136f1e30$2810a8c0 AT epo DOT com DOT tw>
NNTP-Posting-Host:	clio.rice.edu
X-Trace:	joe.rice.edu 1056923564 26974 128.42.105.3 (29 Jun 2003 21:52:44 GMT)
X-Complaints-To:	abuse AT rice DOT edu
NNTP-Posting-Date:	Sun, 29 Jun 2003 21:52:44 +0000 (UTC)
X-NewsEditor:	ED-1.5.9
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com

> I want to use UDMA, but I don't know how to get the physical address of
> the buffer I allocate for that purpose

It all depends on the environment you plan to run with - if you are under
DOS then you can use techniques which are DPMI provider specific to get
the physical address.  Under CWSDPMI you can query the page tables, see:

  http://clio.rice.edu/djgpp/cwsdma2.zip

under PMODE, if EMM386 isn't loaded then paging isn't turned on, and it's
a really easy calculation.

- Raw text -