Absolute addresses, relative addresses

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Article #48

#48

From: Eric Minso
Date: Mon, 25 Aug 2003 09:21

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Hello,

I would like to know a bit more about the use of absolute addresses
and relative addresses.

I have read that Windows DLL have a relocation table : this table is
needed to correct each absolute addresse in the DLL file because you
can't assume the memory location where DLL while be loaded. But, why
don't only use relative addresses ? (because it's not possible, I
guess)

In fact, my questions are :

In which cases can you use relative addresses ?
In which cases must you use absolute addresses ?
In which cases can you choose ? (and which choice is better ? (i.e.
for speed...))

Tell me if I am wrong : you can use relative addresses only inside a
code section, and each time you reference another section, you must
use absolute addresses. Is it right ?

A last question before leaving :-)

This instruction :
mov [ ebp + cst ], val
(with 'ebp' initialised with loading address, and 'cst' initialised
with offset) can solve the absolute addresses problem, so where is the
trap ?

Thank you !

Eric.

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From: minso@altern.org (Eric Minso)
Newsgroups: comp.lang.asm.x86,alt.lang.asm,alt.os.assembly,borland.public.tasm
Subject: Absolute addresses, relative addresses
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