Mailing-List: contact cygwin-developers-help AT sourceware DOT cygnus DOT com; run by ezmlm
List-Subscribe: <mailto:cygwin-developers-subscribe AT sourceware DOT cygnus DOT com>
List-Archive: <http://sourceware.cygnus.com/ml/cygwin-developers/>
List-Post: <mailto:cygwin-developers AT sourceware DOT cygnus DOT com>
List-Help: <mailto:cygwin-developers-help AT sourceware DOT cygnus DOT com>, <http://sourceware.cygnus.com/ml/#faqs>
Sender: cygwin-developers-owner AT sourceware DOT cygnus DOT com
Delivered-To: mailing list cygwin-developers AT sourceware DOT cygnus DOT com
Message-Id: <200001221656.KAA20887@ares.xraylith.wisc.edu>
To: cgf AT cygnus DOT com
Cc: cygwin-developers AT sourceware DOT cygnus DOT com
Subject: Re: binmode idea 
In-Reply-To: Your message of "Sat, 22 Jan 2000 11:35:36 EST."
             <20000122113536 DOT A18995 AT cygnus DOT com> 
Date: Sat, 22 Jan 2000 10:56:36 -0600
From: Mumit Khan <khan AT NanoTech DOT Wisc DOT EDU>

Chris Faylor <cgf AT cygnus DOT com> writes:
> Is there anywhere in an executable header where we could commandeer a 32
> bit word for cygwin's use?  I was thinking that we could write a utility
> that could set bits in this word which would indicate whether the
> default mode was "binmode" for file opens and maybe even other "CYGWIN"
> defaults.
> 
> This is not a replacement for DJ's capability idea but it would allow us
> to create executables that could be copied from system to system with
> no extra setup.
> 
> Mumit, do you know if there is something in an executable that could be
> used like this?
> 
> Alternatively, we could add a linker section for this, but that would
> require relinking an exeutable to gain the benefit.

I looked into this issue for a different purpose a while ago, and came
to the conclusion (now I can't remember why of course ;-) that it's
better and safer to use a separate section that use one of the unused
flags. Of course, I was looking at completely different application, so
the conclusion probably doesn't apply here.

One option is to add a new data directory item, and use that. See the
reference cited below for optional header items in the image files.

The other is of course the section idea, which is a very simple one
to implement.

The third option is to add symbol (ala .gcc_compiled)  that is not to
be stripped away.

The PE-COFF specs are online if you have MSDN (or from MS web site).
Search for "Microsoft Portable Executable and Common Object File Format
Specification". On the net:
  http://msdn.microsoft.com/library/specs/msdn_pecoff.htm

Disclaimer -- I looked into this issue a long time ago, and for a very
different purpose, so there is always the possibility that my conclusion
doesn't apply in this case.

I seem to have missed DJ's capability idea. References?

Regards,
Mumit