.\"	$NetBSD: compat_svr4.8,v 1.26.32.1 2019/09/02 16:39:21 martin Exp $
.\"
.\" Copyright (c) 1996 Christos Zoulas
.\" 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.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\"
.\"	Stolen from compat_linux.8,v 1.2 1995/10/16 20:17:59 fvdl
.\"
.Dd April 19, 1999
.Dt COMPAT_SVR4 8
.Os
.Sh NAME
.Nm compat_svr4
.Nd setup procedure for running SVR4/iBCS2 binaries
.Nm compat_svr4_32
.Nd setup procedure for running 32-bit SVR4/iBCS2 binaries
.Sh DESCRIPTION
.Nx
supports running SVR4/iBCS2 binaries.
This code has been tested on
i386 (with binaries from SCO OpenServer and XENIX), m68k (with binaries from
.Tn AMIX )
and sparc (with binaries from Solaris) systems.
Most programs should work, but not ones that use or depend on:
.sp
.Bl -item -compact -offset indent
.It
kernel internal data structures
.It
the
.Pa /proc
filesystem
.It
the ticotsord loopback RPC mechanism (NIS uses this)
.It
sound and video interfaces
.It
threads (ttsession uses threads)
.It
the streams administrative driver
.El
.sp
The SVR4 compatibility feature is active
for kernels compiled with the
.Dv COMPAT_SVR4
option enabled.
Since support for ELF executables is included
only if the kernel is compiled with the
.Dv EXEC_ELF32
or
.Dv EXEC_ELF64
options enabled, kernels which include
.Dv COMPAT_SVR4
should also typically include
.Dv EXEC_ELF32
(for 32-bit ELF support)
and/or
.Dv EXEC_ELF64
(for 64-bit ELF support).
.Pp
Another compatibility feature is
.Dv COMPAT_SVR4_32 ,
which allows the execution of 32-bit SVR4 binaries on a machine
with a 64-bit kernel.
This requires
.Dv EXEC_ELF32
and
.Dv COMPAT_NETBSD32
options as well as
.Dv COMPAT_SVR4 .
It is configured the same way as
.Dv COMPAT_SVR4
but uses the
.Pa /emul/svr4_32
directory instead of
.Pa /emul/svr4 .
But typically,
.Pa /emul/svr4_32
can be made to point to
.Pa /emul/svr4
if the
operating system donating the libraries has support for both 32-bit
and 64-bit binaries.
.Pp
Execution of 32-bit SVR4 binaries on a machine with a 32-bit kernel uses
.Dv COMPAT_SVR4 ,
not
.Dv COMPAT_SVR4_32 .
.Pp
Most SVR4 programs are dynamically linked.
This means that you will also need the shared libraries that the
program depends on and the runtime linker.
Also, you will need to create a
.Dq shadow root
directory for SVR4 binaries on your
.Nx
system.
This directory is named
.Pa /emul/svr4 .
Any file operations done by SVR4 programs run under
.Nx
will look in this directory first.
So, if a SVR4 program opens, for example,
.Pa /etc/passwd ,
.Nx
will
first try to open
.Pa /emul/svr4/etc/passwd ,
and if that does not exist open the
.Sq real
.Pa /etc/passwd
file.
It is recommended that you install
SVR4 packages that include configuration files, etc under
.Pa /emul/svr4 ,
to avoid naming conflicts with possible
.Nx
counterparts.
Shared libraries should also be installed in the shadow tree.
.Pp
The simplest way to set up your system for SVR4 binaries is:
.Bl -enum -compact
.It
Make the necessary directories:
.Pp
.Bl -tag -width 123 -compact -offset indent
.It (me@netbsd) mkdir -p /emul/svr4/{dev,etc}
.br
.It (me@netbsd) mkdir -p /emul/svr4/usr/{bin,lib,ucblib}
.br
.It (me@netbsd) mkdir -p /emul/svr4/usr/openwin/{bin,lib}
.br
.It (me@netbsd) mkdir -p /emul/svr4/usr/dt/{bin,lib}
.El
.Pp
.It
Copy files from an svr4 system:
.Pp
.Bl -tag -width 123 -compact -offset indent
.It (me@svr4) cd /usr/lib
.br
.It (me@svr4) tar -cf -\ . | \e
.in +5
.It rsh netbsd 'cd /emul/svr4/usr/lib && tar -xpf -'
.in -5
.El
.Pp
.Bl -tag -width 123 -compact -offset indent
.It (me@svr4) cd /usr/ucblib
.br
.It (me@svr4) tar -cf -\ . | \e
.in +5
.It rsh netbsd 'cd /emul/svr4/usr/ucblib && tar -xpf -'
.in -5
.El
.Pp
If you are running openwindows:
.Pp
.Bl -tag -width 123 -compact -offset indent
.It (me@svr4) cd /usr/openwin/lib
.br
.It (me@svr4) tar -cf -\ . | \e
.in +5
.It rsh netbsd 'cd /emul/svr4/usr/openwin/lib && tar -xpf -'
.in -5
.It (me@svr4) cd /usr/dt/lib
.br
.It (me@svr4) tar -cf -\ . | \e
.in +5
.It rsh netbsd 'cd /emul/svr4/usr/dt/lib && tar -xpf -'
.in -5
.El
.It
You will also probably need the timezone files from your Solaris
system, otherwise emulated binaries will run on UTC time.
.Pp
.Bl -tag -width 123 -compact -offset indent
.It (me@netbsd) mkdir -p /emul/svr4/usr/share/lib/zoneinfo
.br
.It (me@netbsd) mkdir -p /emul/svr4/etc/default
.br
.It (me@svr4) cd /usr/share/lib/zoneinfo
.br
.It (me@solaris) tar -cf - . | \e
.in +5
.It rsh netbsd 'cd /emul/svr4/usr/share/lib/zoneinfo &&
.It tar -xpf -'
.in -5
.br
.It (me@netbsd) echo TZ=US/Pacific > /emul/svr4/etc/default/init
.br
.El
.It
Set up the configuration files and devices:
.Pp
.Bl -tag -width 123 -compact -offset indent
.It (me@netbsd) cd /usr/share/examples/emul/svr4/etc
.br
.It (me@netbsd) cp netconfig nsswitch.conf /emul/svr4/etc
.br
.It (me@netbsd) cp SVR4_MAKEDEV /emul/svr4/dev
.br
.It (me@netbsd) cd /emul/svr4/dev && sh SVR4_MAKEDEV all
.El
.Pp
As the major number allocated for emulation of SVR4 devices may vary between
.Nx
platforms, the SVR4_MAKEDEV script uses the
.Xr uname 1
command to determine the architecture the devices nodes are being created for;
this can be overridden by setting the
.Ev MACHINE
environment variable accordingly.
.El
.Pp
An alternative method is to mount a whole SVR4 partition in
.Pa /emul/svr4
and then override with other mounts
.Pa /emul/svr4/etc
and
.Pa /emul/svr4/dev .
.Sh BUGS
Many system calls are still not emulated.
The streams emulation is
incomplete (socketpair does not work yet).
.Pp
Most SVR4 executables can not handle directory offset cookies > 32
bits.
More recent ones, compiled for large file support (Solaris 2.6 and up) can.
With older programs, you will see the message
.Dq svr4_getdents: dir offset too large for emulated program
when this happens.
Currently, this can only happen on NFS mounted filesystems, mounted
from servers that return offsets with information in the upper 32 bits.
These errors should rarely happen, but can be avoided by mounting
this filesystem with offset translation enabled.
See the
.Fl X
option to
.Xr mount_nfs 8 .
The
.Fl 2
option to
.Xr mount_nfs 8
will also have the desired effect, but is less preferable.