NAME
compat_svr4 —
setup procedure for
running SVR4/iBCS2 binaries compat_svr4_32 —
setup procedure for running 32-bit SVR4/iBCS2 binaries
DESCRIPTION
NetBSD supports running SVR4/iBCS2 binaries. This code
has been tested on i386 (with binaries from SCO OpenServer and XENIX), m68k
(with binaries from AMIX) and sparc (with binaries from Solaris) systems. Most
programs should work, but not ones that use or depend on:
- kernel internal data
structures
- the /proc
filesystem
- the ticotsord loopback RPC
mechanism (NIS uses this)
- sound and video
interfaces
- threads (ttsession uses
threads)
- the streams administrative
driver
The SVR4 compatibility feature is active for kernels compiled with the
COMPAT_SVR4
option enabled. Since support for ELF
executables is included only if the kernel is compiled with the
EXEC_ELF32
or
EXEC_ELF64
options enabled, kernels which include
COMPAT_SVR4
should also typically include
EXEC_ELF32
(for 32-bit
ELF support) and/or
EXEC_ELF64
(for 64-bit ELF
support).
Another compatibility feature is
COMPAT_SVR4_32
, which
allows the execution of 32-bit SVR4 binaries on a machine with a 64-bit
kernel. This requires
EXEC_ELF32
and
COMPAT_NETBSD32
options as well as
COMPAT_SVR4
. It is configured the same way as
COMPAT_SVR4
but uses the
/emul/svr4_32 directory instead of
/emul/svr4. But typically,
/emul/svr4_32
can be made to point to
/emul/svr4 if the operating system
donating the libraries has support for both 32-bit and 64-bit binaries.
Execution of 32-bit SVR4 binaries on a machine with a 32-bit kernel uses
COMPAT_SVR4
, not
COMPAT_SVR4_32
.
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 “shadow root” directory for SVR4
binaries on your
NetBSD system. This directory is
named
/emul/svr4. Any file operations done by SVR4 programs
run under
NetBSD will look in this directory first.
So, if a SVR4 program opens, for example,
/etc/passwd,
NetBSD will first try to open
/emul/svr4/etc/passwd, and if that does not exist open the
‘real’
/etc/passwd file. It is recommended that
you install SVR4 packages that include configuration files, etc under
/emul/svr4, to avoid naming conflicts with possible
NetBSD counterparts. Shared libraries should also be
installed in the shadow tree.
The simplest way to set up your system for SVR4 binaries is:
- Make the necessary
directories:
- (me@netbsd) mkdir -p
/emul/svr4/{dev,etc}
-
- (me@netbsd) mkdir -p
/emul/svr4/usr/{bin,lib,ucblib}
-
- (me@netbsd) mkdir -p
/emul/svr4/usr/openwin/{bin,lib}
-
- (me@netbsd) mkdir -p
/emul/svr4/usr/dt/{bin,lib}
-
- Copy files from an svr4
system:
- (me@svr4) cd
/usr/lib
-
- (me@svr4) tar -cf
- . | \
-
- rsh netbsd 'cd
/emul/svr4/usr/lib && tar -xpf -'
-
- (me@svr4) cd
/usr/ucblib
-
- (me@svr4) tar -cf
- . | \
-
- rsh netbsd 'cd
/emul/svr4/usr/ucblib && tar -xpf -'
-
If you are running openwindows:
- (me@svr4) cd
/usr/openwin/lib
-
- (me@svr4) tar -cf
- . | \
-
- rsh netbsd 'cd
/emul/svr4/usr/openwin/lib && tar -xpf -'
-
- (me@svr4) cd
/usr/dt/lib
-
- (me@svr4) tar -cf
- . | \
-
- rsh netbsd 'cd
/emul/svr4/usr/dt/lib && tar -xpf -'
-
- You will also probably need
the timezone files from your Solaris system, otherwise emulated binaries
will run on UTC time.
- (me@netbsd) mkdir -p
/emul/svr4/usr/share/lib/zoneinfo
-
- (me@netbsd) mkdir -p
/emul/svr4/etc/default
-
- (me@svr4) cd
/usr/share/lib/zoneinfo
-
- (me@solaris) tar -cf -. |
\
-
- rsh netbsd 'cd
/emul/svr4/usr/share/lib/zoneinfo &&
-
- tar -xpf -'
-
- (me@netbsd) echo
TZ=US/Pacific > /emul/svr4/etc/default/init
-
- Set up the configuration files
and devices:
- (me@netbsd) cd
/usr/share/examples/emul/svr4/etc
-
- (me@netbsd) cp netconfig
nsswitch.conf /emul/svr4/etc
-
- (me@netbsd) cp
SVR4_MAKEDEV /emul/svr4/dev
-
- (me@netbsd) cd
/emul/svr4/dev && sh SVR4_MAKEDEV all
-
As the major number allocated for emulation of SVR4 devices may vary between
NetBSD platforms, the SVR4_MAKEDEV script uses the
uname(1) command to determine
the architecture the devices nodes are being created for; this can be
overridden by setting the MACHINE
environment
variable accordingly.
An alternative method is to mount a whole SVR4 partition in
/emul/svr4 and then override with other mounts
/emul/svr4/etc and
/emul/svr4/dev.
BUGS
Many system calls are still not emulated. The streams emulation is incomplete
(socketpair does not work yet).
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 “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
-X option to
mount_nfs(8). The
-2 option to
mount_nfs(8) will also have
the desired effect, but is less preferable.