Newsgroups: comp.os.linux,comp.os.coherent
Path: sparky!uunet!think.com!cass.ma02.bull.com!mips2!bubba!sje
From: s...@xylos.ma30.bull.com (Steven J. Edwards)
Subject: Are Linux executables compatable with Coherent 4.0?
Reply-To: s...@xylos.ma30.bull.com
Organization: Bull HN, Worldwide Information Systems, Billerica, Mass., USA
Distribution: comp
Date: 16 Jul 92 14:27:50
Message-ID: <SJE.92Jul16142750@xylos.ma30.bull.com>
Sender: n...@mips2.ma30.bull.com (Usenet News Manager)
Lines: 21

The beta version of MWC Coherent 4.0 (32 bit flat addressing for the
386+ CPU family) claims that it has SCO executable compatability for
character I/O programs at the Intel Binary Interoperatibility Level
(or whatever).  MWC has gotten gcc to run allowing the production of
ASNI C applications.  However, there are only a limited number (less
than 10) of officially converted applications.  Given the apparently
large number of programs now working under Linux, I was wondering if
any of the Linux binaries, particularly gcc, may be run under Coherent
4.0 without modification.  Also, it would be interesting if the
reverse was true.

Is there anyone out there with definitive information about this?  If
the two operating systems had compatable executable formats, then it
seems that we could all save some time as long porting candidates did
not use OS specific functions.

 [The above opinions expressed are my own; not necessarily held by others.]
      == Steven J. Edwards           Bull HN Information Systems Inc. ==
      == (508) 294-3484              300 Concord Road         MS 820A ==
      == s...@xylos.ma30.bull.com     Billerica, MA 01821          USA ==
"That Government which Governs the Least, Governs Best." -- Thomas Jefferson

From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroups: comp.os.linux,comp.os.coherent
Subject: Re: Are Linux executables compatable with Coherent 4.0?
Date: 16 Jul 92 22:25:59 GMT
Distribution: comp
Organization: University of Helsinki

In article < SJE.92Jul16142750@xylos.ma30.bull.com> sje@xylos.ma30.bull.com writes:
>The beta version of MWC Coherent 4.0 (32 bit flat addressing for the
>386+ CPU family) claims that it has SCO executable compatability for
>character I/O programs at the Intel Binary Interoperatibility Level
>(or whatever).  MWC has gotten gcc to run allowing the production of
>ASNI C applications.  However, there are only a limited number (less
>than 10) of officially converted applications.  Given the apparently
>large number of programs now working under Linux, I was wondering if
>any of the Linux binaries, particularly gcc, may be run under Coherent
>4.0 without modification.  Also, it would be interesting if the
>reverse was true.

No, linux binaries won't work under Coh4.0 nor vice versa.  I don't know
if the actual header is a problem (linux uses the standard a.out header
that gcc produces), but system calls aren't handled the same way.  I
personally think binary compatability is evil (or at least unnecessary)
and in most cases just forces old mistakes on a new product etc (just
look at DOS).  And as there aren't any binaries available with the
standard i386 ABI anyway that I could afford and want to run, I saw no
reason to even try. 

[ Not to mention the fact that I haven't got any information at all on
the "standard" binary interface - which makes things a bit hard to
program :-) ]

Of course, somebody might try to write a system call emulator that does
the necessary translations, but it would probably be pretty ugly.  I
don't even know how a system call is handled under normal i386 unices:
linux uses "int $0x80" with all the necessary info in the registers, but
there are several other possibilities available (jumping through a
trap-gate with or without stack copying etc), and the chances that I
would hit on the same interface as other 386-unices are pretty slim. 

		Linus