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Mail Archives: djgpp/1993/09/14/20:45:54

From: "Rodney W. Grimes" <rgrimes AT gndrsh DOT cdrom DOT com>
Subject: Re: Accessing real memory (ie, below 1MB) under go32
To: dj AT ctron DOT com (DJ Delorie)
Date: Tue, 14 Sep 1993 17:18:43 -0700 (PDT)
Cc: sandmann AT clio DOT rice DOT edu, djgpp AT sun DOT soe DOT clarkson DOT edu

> 
> 
> > There is a 4K buffer in low memory (___transfer_buffer contains the 
> > 32 bit address in .s gas code).  This value is currently only set for non-DPMI
> > mode (and is NULL for DPMI).  This area can be used if you understand the
> > GO32 extender calls which use it and don't interfere with them.
> 
> As of 1.11 this area is available in all modes.

And I was hacking on using this now for my work, but see below...

> > If you are willing to do DPMI only, you can call the Int 31h call to allocate
> > low memory under DPMI.  This is probably better, since I believe V1.11
> > emulates this DPMI function for non-DPMI, so you would have future
> > compatibility built in (is this correct DJ?)
> 
> Correct.
> 
> > Finally, I know that for one commercial software project that has
> > been recently done with DJGPP they needed to add Int 13 support to the
> > extender.  Maybe it's time to put that in the release?
> 
> 1.11's DPMIsim makes that kind of change to go32.exe obsolete.  I have
> yet to work in extension mechanisms for int86() though.

Perhaps we are duplicating work here... I also saw in another note that
some one had int 13 stuff working for some commercial application that
required it (my work is also commercial) and was wondering if said work
was availiable as patches?

I really hate to reinvent the wheel!

On a side note, I noted that most of your c library is based up on the
Net/2  release, a lot of that code has since been updated and is now
availiable from ftp.uu.net and was wondering if you plan to upgrade the
libraries at any time.  (Reason I ask is that I cross compile under
FreeBSD which has a lot of the new 4.4 library code and I have to keep
2 sets of the headers around and be real carefull :-()

-- 
Rod Grimes						     rgrimes AT cdrom DOT com

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