From: sandmann AT clio DOT rice DOT edu (Charles Sandmann)
Message-Id: <10105261727.AA13828@clio.rice.edu>
Subject: Re: SRAM chip access problem
To: eliz AT is DOT elta DOT co DOT il
Date: Sat, 26 May 2001 12:27:33 -0500 (CDT)
Cc: alex AT compuweigh DOT com (Alex Oleynikov), djgpp AT delorie DOT com
In-Reply-To: <2593-Sat26May2001100124+0300-eliz@is.elta.co.il> from "Eli Zaretskii" at May 26, 2001 10:01:24 AM
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> > (BTW, how do you know whether it is code or data segment just by looking at
> > the selector's value? Isn't this information available only from the
> > descriptor to which this selector points in the LDT?).
> 
> The selector itself (c7) looked to me like a code selector.  Charles,
> did I miss something?

You can't tell the selector information from the number, only it's
ring-protection status.  You would have to use LAR to get the code/data
status.  Selectors in DJGPP are 7/f/7/f alternating returned end nibble
values when the DPMI provider returns them sequentially.  The low 2
bits show requested priv, the next bit (0x4) ldt/gdt status.