path: root/share/man/man8/compat_ibcs2.8

.\"	$OpenBSD: compat_ibcs2.8,v 1.1 1998/02/09 21:58:21 deraadt Exp $
.\"
.\" Copyright (c) 1998 Scott Bartram
.\" Copyright (c) 1995 Frank van der Linden
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"      This product includes software developed for the NetBSD Project
.\"      by Scott Bartram and Frank van der Linden
.\" 4. The name of the author may not be used to endorse or promote products
.\"    derived from this software without specific prior written permission
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.\"
.\" Based on compat_linux.8
.\"
.Dd February 8, 1998
.Dt COMPAT_IBCS2 8
.Os OpenBSD
.Sh NAME
.Nm compat_ibcs2
.Nd setup procedure for running iBCS2 binaries
.Sh DESCRIPTION
.Nx
supports running Intel Binary Compatibilty Standard 2 (iBCS2)
binaries.  This only applies to i386 systems for now.  Binaries
are suported from SCO UNIX and other systems derived from UNIX
System V Release 3. iBCS2 support is only well tested using SCO
binaries. XENIX binaries are also supported although not as well
tested.  SVR4 binaries are supported by the
.Dv COMPAT_SVR4
option.
.Pp
iBCS2 supports COFF, ELF, and x.out (XENIX) binary formats. Binaries
from SCO OpenServer (version 5.x) are the only ELF binaries that have
been tested.  Most programs should work, but not ones that use or
depend on:
.sp
.Bl -tag -width 123 -compact -offset indent
.It kernel internal data structures
.br
.It STREAMS drivers (other than TCP/IP sockets)
.br
.It local X displays (uses a STREAMS pipe)
.br
.It virtual 8086 mode
.El
.sp
The iBCS2 compatibility feature is active for kernels compiled with
the
.Dv COMPAT_IBCS2
option enabled.  If support for iBCS2 ELF executables is desired,
the
.Dv EXEC_ELF32
option should be enabled in addition to
.Dv COMPAT_IBCS2 .
.Pp
Many COFF-format programs and most ELF-format programs are dynamically
linked. This means that you will also need the shared libraries that
the program depends on.  Also, you will need to create a "shadow root"
directory for iBCS2 binaries on your OpenBSD system. This directory is
named /emul/ibcs2.  Any file operations done by iBCS2 programs run
under OpenBSD will look in this directory first. So, if an iBCS2
program opens, for example, /etc/passwd, OpenBSD will first try to open
/emul/ibcs2/etc/passwd, and if that does not exist open the 'real'
/etc/passwd file. It is recommended that you install iBCS2 packages
that include configuration files, etc. under /emul/ibcs2, to avoid
naming conflicts with possible OpenBSD counterparts. Shared libraries
should also be installed in the shadow tree.
.Pp
Generally, you will need to look for the shared libraries that
iBCS2 binaries depend on only the first few times that you install
an iBCS2 program on your OpenBSD system. After a while, you will
have a sufficient set of iBCS2 shared libraries on your system to
be able to run newly imported iBCS2 binaries without any extra
work.

.Ss Setting up shared libraries
How to get to know which shared libraries iBCS2 binaries need, and
where to get them? Depending on the file type of the executable, there
are different possibilities (when following these instructions: you
will need to be root on your OpenBSD system to do the necessary
installation steps).

.Bl -tag -width 123 -compact
.It 1. COFF binaries
You can simply copy all of the available shared libraries since they
are fairly small in size. The COFF shared libraries are typically
found in /shlib and can be obtained from the following sources:
.sp
.nf
SCO UNIX version 3.x (aka ODT)
SCO UNIX version 5.x (aka OpenServer)
SCO UnixWare
Many versions of SVR4.2/x86
.fi
.sp
After copying the shared libraries, you should have at least the
following files on your system:
.Pp
.nf
/emul/ibcs2/shlib/libc_s
/emul/ibcs2/shlib/libnsl_s
/emul/ibcs2/shlib/protlib_s
.fi
.Pp
.It 2. ELF binaries
You can simply copy all of the available shared libraries from the
source system or distribution or use the `ldd-elf' program (in
development) to determine the libraries required by a specific binary.
.Pp
After copying the shared libraries, you should have at least the
following files on your system:
.Pp
.nf
/emul/ibcs2/usr/lib/libc.so.1
/emul/ibcs2/usr/lib/libcrypt.so
/emul/ibcs2/usr/lib/libndbm.so
/emul/ibcs2/usr/lib/libsocket.so.1
.fi
.Pp
.El
If you don't have access to a SCO system, you will need to get the
extra files you need from a SCO distribution. As of January 1998, SCO
sells a copy of SCO OpenServer (iBCS2) and/or SCO UnixWare (SVR4) for
personal/non-commercial use for only the cost of shipping (about
$20US). The distribution comes on an ISO9660-format CDROM which can be
mounted and used to copy the necessary files.
.Pp
Run the following script to copy the basic set of files from a SCO
distribution directory mounted somewhere locally:
.Pp
.nf
/usr/share/examples/emul/ibcs2/ibcs2-setup [directory]
.fi
.Pp
You should now be set up for SCO binaries which only need standard
shared libs.
.Sh BUGS
The information about SCO distributions may become outdated.
.Pp
Attempting to a use a nameserver on the local host does not currently
work due to an absurd shortcut taken by the iBCS2 network code
(remember that there are no kernel sockets).
.Pp
16/32/64 bit offsets may not be handled correctly in all cases.