Article View: comp.lang.asm.x86
Article #56Re: Absolute addresses, relative addresses
From: hp
Date: Wed, 27 Aug 2003 08:07
Date: Wed, 27 Aug 2003 08:07
41 lines
3480 bytes
3480 bytes
Jeff wrote:
>
> "hp" <phpr@snafu.de> wrote in message
> news:bifme4$fh$1@news.eusc.inter.net...
>
>> > I have read that Windows DLL have a relocation table : this table is
>>
>> quite common, other dll models have those tables,too.
>> they are required because i86 cpu-s (and others) do not provide a
> sufficient
>> set of operations to efficiently supporting relocatable code w.o. those
>> tables (as for instance, the 680xx processors do).
>
> Which 680xx instructions support this mechanism?
right. you'd put me back to reality...:
all op-s which access memory have a PC-relative referencing mode plus, BSR
which is a PC-rel subroutine call which is not limited by disp. figure.
thus no need to any absolute reference but memory mapped i/o (no 'port's
exist) or special purpose addresses which are known by convention.
some kind of a starter program (e.g. linux 'execve') would always need to
'know' the entry point by it's true (whatever access mode) address, but the
program itself won't need a single one absolute reference.
besides, talking about a program's own memory; ref to others' or to external
library code would be different. though the 680xx cpu-s have more gp regs,
which makes rel. ref to the 'outer world' easier but not different wrt i86.
and, detailed analysis of (imho, fairly poor) run-time efficiency is another
point which would belong to another discussion, though.
regards,
hp
--
>>> (hp)at(lxhp)dot(in-berlin)dot(de) <<<
linux,asm,forth http.//www.lxhp.in-berlin.de
Technical Details
Message-ID:
<bihlck$ne6$1@news.eusc.inter.net>Path:
arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-06!sn-post-01!supernews.com!corp.supernews.com!news.crayne.org!clax86!robomod!not-for-mailReferences:
<7db38e60.0308250121.6135ebc1@posting.google.com> <bifme4$fh$1@news.eusc.inter.net> <3f4c1c51@nocnews001.allthesites.org>Show Full Headers
Complete Article Headers
X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: feaef,44f17f79ebe31523 X-Google-Attributes: gidfeaef,public X-Google-Thread: f7d8d,44f17f79ebe31523 X-Google-Attributes: gidf7d8d,public X-Google-Thread: 114917,44f17f79ebe31523 X-Google-Attributes: gid114917,public X-Google-Thread: 1093da,44f17f79ebe31523 X-Google-Attributes: gid1093da,public X-Google-ArrivalTime: 2003-08-27 02:56:56 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!sn-xit-02!sn-xit-06!sn-post-01!supernews.com!corp.supernews.com!news.crayne.org!clax86!robomod!not-for-mail From: hp <phpr@snafu.de> Newsgroups: comp.lang.asm.x86,alt.lang.asm,alt.os.assembly,borland.public.tasm Subject: Re: Absolute addresses, relative addresses Approved: CLAX86 Moderators <ccrayne@crayne.org> Followup-To: comp.lang.asm.x86 Date: Wed, 27 Aug 2003 09:07:26 +0100 Organization: Lux1 Message-ID: <bihlck$ne6$1@news.eusc.inter.net> X-CLAX86-Policy: http://www.pacificsites.com/~ccrayne/clax86.html X-CLAX86-Faq: http://www.faqs.org/faqs/by-newsgroup/comp/comp.lang.asm.x86.html X-CLAX86-Info-1: Send submissions to comp-lang-asm-x86@moderators.isc.org X-CLAX86-Info-2: Send technical complaints to ccrayne@crayne.org X-CLAX86-Info-3: Send complaints about policy to ccrayne@crayne.org X-Comment: moderators do not necessarily agree or disagree with this article. References: <7db38e60.0308250121.6135ebc1@posting.google.com> <bifme4$fh$1@news.eusc.inter.net> <3f4c1c51@nocnews001.allthesites.org> Reply-To: phpr@snafu.de Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit X-MailScanner-Information: Please contact the ISP for more information X-MailScanner: Found to be clean X-MailScanner-SpamCheck: not spam (whitelisted), SpamAssassin (score=-1, required 4, QUOTED_EMAIL_TEXT -0.48, REFERENCES -0.50) X-UIDL: lm&#!FLF"!Vhh!!$a3"! X-Complaints-To: abuse@supernews.com Lines: 42