From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_FONT_LOW_CONTRAST,HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 28887 invoked from network); 25 Feb 2023 15:31:10 -0000 Received: from minnie.tuhs.org (50.116.15.146) by inbox.vuxu.org with ESMTPUTF8; 25 Feb 2023 15:31:10 -0000 Received: from minnie.tuhs.org (localhost [IPv6:::1]) by minnie.tuhs.org (Postfix) with ESMTP id 60E8C4228E; Sun, 26 Feb 2023 01:31:01 +1000 (AEST) Received: from mail-vs1-xe2c.google.com (mail-vs1-xe2c.google.com [IPv6:2607:f8b0:4864:20::e2c]) by minnie.tuhs.org (Postfix) with ESMTPS id 134C34228B for ; Sun, 26 Feb 2023 01:30:53 +1000 (AEST) Received: by mail-vs1-xe2c.google.com with SMTP id df20so4211208vsb.3 for ; Sat, 25 Feb 2023 07:30:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ccc.com; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=M42mo69miYA4d9xePfl1vHaVuOA3Z74dzfQZkyix8wY=; b=D8mr7n7ad0z/iDdblFPuhvTLCZsgWdrlsom0CxelXbix2YulKVi68EJJRAyinnGyLH iAuLOWisu6h28iJvg7ISZXPXqsAPH2QQ9vuDyf6DyZtIMNnQfCu6XlhUUgFuUPtq27JX FSRHW18KzZsGMUuJZ+vxHl39YHi/fF5rb74gE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=M42mo69miYA4d9xePfl1vHaVuOA3Z74dzfQZkyix8wY=; b=uElZLL8s4Vqd9S4H29kYzdo7l6Q3G3lj4jrmgEhUy8Oa//78owx33i6N8YKpPyrqku nScEijDUHKuMhjEKQWZ2xlLyvXPeEWNp+pJhOIwKGXvxdVfj/9h9ovaIyqaAj4gcpqKG M2yztxw1jjLhv+vNAO/6Rstzf/IxTeJXU4w4B36P/aiD7ZnzkDgSpF5cf1TwIvORmM3R G3iZb8xrJ9MDUtXIcXtsH3M5TNBbx2Y8epzD1JS7+Z+0CcXVsILNtgGfByC1G7ZID+P9 ObqRzXRBrDg9etwJ0H6P1F96GfHjS4h2FJziHc/VPSbN77u+R0+Iw/GMKXbqXDsNQAAr JLxw== X-Gm-Message-State: AO0yUKVomVLfAUGpXBUxuTfscMSTIyrwHUOooE0B/Jh5IyDvbyUFjqaV L2w/5TJiHwoWK0NpX0iEtfZvlH/Ti9lINdIOJyaMtVaJPIR+uZIkASU= X-Google-Smtp-Source: AK7set+eQ2StTk/rB8rOlZAiMZ7z2k2u/g+rHFOWedeXfljLr1fzIQr4QvuOFFEGWvtl3v17CuUxZZ86NJ5ZVffk5xo= X-Received: by 2002:a05:6122:b74:b0:40c:4d1:b550 with SMTP id h20-20020a0561220b7400b0040c04d1b550mr4381917vkf.0.1677339051574; Sat, 25 Feb 2023 07:30:51 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Clem Cole Date: Sat, 25 Feb 2023 10:30:25 -0500 Message-ID: To: Dave Horsfall Content-Type: multipart/alternative; boundary="000000000000565e0105f587eecc" Message-ID-Hash: KFD6KDR7V5FUIIAMZTCQDDIG72DUZAOJ X-Message-ID-Hash: KFD6KDR7V5FUIIAMZTCQDDIG72DUZAOJ X-MailFrom: clemc@ccc.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: The Eunuchs Hysterical Society X-Mailman-Version: 3.3.6b1 Precedence: list Subject: [TUHS] Re: Origins of the SGS (System Generation Software) and COFF (Common Object File Format) List-Id: The Unix Heritage Society mailing list Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --000000000000565e0105f587eecc Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, Feb 24, 2023 at 9:07 PM Dave Horsfall wrote: > On Thu, 23 Feb 2023, Paul Winalski wrote: > > > a.out was, as object file formats go, a throwback to the stone age from > > the get-go. Even the most primitive of IBM's link editors for > > System/360 supported arbitrary naming of object file sections and the > > ability for the programmer to arrange them in whatever order they > > wished. a.out's restriction to three sections (.text, .data, .bss) did > > manage to get the job done, and even (with ZMAGIC) could support > > demand-paged virtual memory, but only just. > > That may be so, but those guys didn't exactly have the resources of > IBM behind them... > A reasonable point, but it was more Ken, Dennis, and the team did what >>they needed<< and it was good enough for a long time. The IBM link editors needed all that back in the day. As more and more "modern" languages came into being, it was not until about 6th editions that difficulties of not having an expandable object format and better linker began to show, and as Paul says, until the support for demand paging that a.out was really stressed. Please correct me if I'm misinformed, but Paul, of course, had to support the DEC language tools on Unix, which had come from systems that had a more flexible format (the solution for Ultrix IICR was to move a flavor of the VMS linker to UNIX for object file and just a.out for execution). So he lived the difficulties/shortcomings. A valid argument is Tanndenbaum's compiler toolkit survived with a.out, and he supported many of the same language targets that DEC did. Andy and crew did their own assemblers, does anyone remember if they supplied a new linker and object format? That would make Paul's point more powerful -> the languages people wanted something more. My point, the UNIX developers built what they needed and built that well. Their format worked with their development primary language/tool (a.k.a. C) and they even made it work with an f77 implementation. So it is a little hard to knock them too much -- it was not part of the original design spec. But as Matt has discussed in his digging through things, it does look like as the AT&T languages team started to run into some of the same barriers, they started to move to a new format. And I wonder how many people here know the significance of the "407" magic > number? > Today, few and fewer I fear. For those do not, please see page 4-33 of the 1975/76 DEC PDP-11 Processor Handbook and think about boot blocks. =F0=9F= =8D=BA =E1=90=A7 --000000000000565e0105f587eecc Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On F= ri, Feb 24, 2023 at 9:07 PM Dave Horsfall <dave@horsfall.org> wrote:
On Thu, 23 Feb 202= 3, Paul Winalski wrote:

> a.out was, as object file formats go, a throwback to the stone age fro= m
> the get-go.=C2=A0 Even the most primitive of IBM's link editors fo= r
> System/360 supported arbitrary naming of object file sections and the =
> ability for the programmer to arrange them in whatever order they
> wished.=C2=A0 a.out's restriction to three sections (.text, .data,= .bss) did
> manage to get the job done, and even (with ZMAGIC) could support
> demand-paged virtual memory, but only just.

That may be so, but those guys didn't exactly have the resources of
IBM behind them...
A reasonable point, but = it was more Ken, Dennis, and the team did what >>they needed<< = and it was good enough for a long time.=C2=A0 The IBM link edito= rs needed all that back in the day.=C2=A0=C2=A0As more and more "modern&= quot; languages=C2=A0came into being, it was not until about 6th editions tha= t difficulties of not having an expandable object format and better linker = began to show, and as Paul says, until the support for demand paging th= at a.out was really stressed.

Please correct me if I&#= 39;m misinformed, but Paul, of course, had to support the DEC language tool= s on Unix, which had come from systems that had a more flexible format (the= solution for Ultrix IICR was to move a flavor of the VMS linker to UNIX fo= r object file and just a.out for execution).=C2=A0 =C2=A0So he lived the di= fficulties/shortcomings.=C2=A0 A valid argument is Tanndenbaum's compil= er toolkit survived with=C2=A0a.out, and he supported many of the same lang= uage targets that DEC did.=C2=A0 Andy and crew did their own assemblers, do= es anyone remember if they supplied a new linker and object format? That wo= uld make Paul's point more powerful -> the languages people wanted s= omething more.

My point, the UNIX developers built wha= t they needed and built that well.=C2=A0 Their=C2=A0format worked with thei= r development primary language/tool (a.k.a. C) and they even made it work w= ith an f77 implementation. So it is a little hard to knock them too much --= it was not part of the original design spec.

But as = Matt has discussed in his digging through things, it does look like as the = AT&T languages team started to run into some of the same barriers, they= started to move to a new format.


=
And I wonder how many people here know the significance of the "407&qu= ot; magic
number?
Today, few and fewer I fear.=C2=A0 = For those do not, please see page 4-33 of the 1975/76 DEC PDP-11 Processor = Handbook=C2=A0and think about boot blocks.=C2=A0=C2=A0=F0= =9F=8D=BA
3D""=E1=90=A7
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