Date: Thu, 2 Dec 1999 13:25:08 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender: eliz AT is
To: Prashant TR <prashant_news AT yahoo DOT com>
cc: Gareth Williams <ghw2002tii AT hotmail DOT com>,
        DJGPP Mailing list <djgpp AT delorie DOT com>
Subject: Re: Setting a variable's selector?
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On Thu, 2 Dec 1999, Prashant TR wrote:

> >This is not necessarily true: in protected mode, at least in
> >principle, you can set up a selector to span any range of addresses in
> >the 4GB address space.  The code in ROM does have an address, so it
> >can be inluded.
> 
> I meant that you cannot write something there in the ROM.

I understood the original message to mean that some chunk of writable 
memory should be set up to be part of the same selector as the read-only 
code in ROM.

> And btw, Eli, are you talking about are the .text, .data and .bss
> segments (or sections).

What I said is true for any segment in protected mode.

But note that I was talking about segments and selectors, not about
sections.  .text, .data and .bss are sections, not segments.  In the 
DJGPP run-time memory layout, .data and .bss (and also the stack and the 
heap) are accessed via one selector, and .text via another.  (However, 
both these selectors have the same base address and the same limit, so 
they basically point to the same memory, albeit with different access 
rights.)