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From: Michael Graff <explorer@flame.org>
Newsgroups: comp.unix.bsd.netbsd.misc
Subject: Re: COMPAT_FREEBSD
Date: 10 Aug 1996 23:45:22 -0400
Organization: flame.org: yes, we do know everything
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banshee@cats.ucsc.edu (Wailer at the Gates of Dawn) writes:
> There is no COMPAT_FREEBSD man page so what are the issues involved in
> running freebsd binaries under netbsd? The general problem I've had
> involves (no surprise here) dynamic libraries and the desire of freebsd
> binaries to look for and try to load the netbsd libraries.
>
> Is there a foolproof way, given a whole set of freebsd libs, to get
> netbsd to run dynamic freebsd binaries? How about the other way round?
> /emul/NetBSD under freebsd?
Here is the man page I just committed a few days ago. It's older than
it should be, but better than nothing, which was what was there.
COMPAT_FREEBSD(8) NetBSD System Manager's Manual COMPAT_FREEBSD(8)
NAME
COMPAT_FREEBSD - setup procedure for running FreeBSD binaries
DESCRIPTION
NetBSD supports running FreeBSD binaries. Most binaries should work, ex-
cept programs that use FreeBSD-specific features. These include
i386-specific calls, such as syscons utilities, and audio devices. The
FreeBSD compatibility feature is active for kernels compiled with the
COMPAT_FREEBSD option enabled.
A lot of programs are dynamically linked. This means, that you will also
need the FreeBSD shared libraries that the program depends on, and the
runtime linker. Also, you will need to create a "shadow root" directory
for FreeBSD binaries on your NetBSD system. This directory is named
/emul/freebsd. Any file operations done by FreeBSD programs run under
NetBSD will look in this directory first. So, if a FreeBSD program opens,
for example, /etc/passwd, NetBSD will first try to open
/emul/freebsd/etc/passwd, and if that does not exist open the 'real'
/etc/passwd file. It is recommended that you install FreeBSD packages
that include configuration files, etc under /emul/freebsd, to avoid nam-
ing conflicts with possible NetBSD counterparts. Shared libraries should
also be installed in the shadow tree.
Generally, you will need to look for the shared libraries that FreeBSD
binaries depend on only the first few times that you install a FreeBSD
program on your NetBSD system. After a while, you will have a sufficient
set of FreeBSD shared libraries on your system to be able to run newly
imported FreeBSD binaries without any extra work.
Setting up shared libraries
How to get to know which shared libraries FreeBSD binaries need, and
where to get them? Basically, there are 2 possibilities (when following
these instructions: you will need to be root on your NetBSD system to do
the necessary installation steps).
1. You have access to a FreeBSD system. In this case you can temporari-
ly install the binary there, see what shared libraries it needs, and
copy them to your NetBSD system. Example: you have just ftp-ed the
FreeBSD binary of SimCity. Put it on the FreeBSD system you have ac-
cess to, and check which shared libraries it needs by running `ldd
sim':
me@freebsd% ldd /usr/local/lib/SimCity/res/sim
/usr/local/lib/SimCity/res/sim:
-lXext.6 => /usr/X11R6/lib/libXext.so.6.0 (0x100c1000)
-lX11.6 => /usr/X11R6/lib/libX11.so.6.0 (0x100c9000)
-lc.2 => /usr/lib/libc.so.2.1 (0x10144000)
-lm.2 => /usr/lib/libm.so.2.0 (0x101a7000)
-lgcc.261 => /usr/lib/libgcc.so.261.0 (0x101bf000)
You would need go get all the files from the last column, and put
them under /emul/freebsd. This means you eventually have these files
on your NetBSD system:
/emul/freebsd/usr/X11R6/lib/libXext.so.6.0
/emul/freebsd/usr/X11R6/lib/libX11.so.6.0
/emul/freebsd/usr/lib/libc.so.2.1
/emul/freebsd/usr/lib/libm.so.2.0
/emul/freebsd/usr/lib/libgcc.so.261.0
Note that if you already have a FreeBSD shared library with a match-
ing major revision number to the first column of the 'ldd' output,
you won't need to copy the file named in the last column to your
system, the one you already have should work. It is advisable to
copy the shared library anyway if it is a newer version, though. You
can remove the old one. So, if you have these libraries on your sys-
tem:
/emul/freebsd/usr/lib/libc.so.2.0
and you find that the ldd output for a new binary you want to in-
stall is:
-lc.2 => /usr/lib/libc.so.2.1 (0x10144000)
you won't need to worry about copying /usr/lib/libc.so.2.1 too, be-
cause the program should work fine with the slightly older version.
You can decide to replace the libc.so anyway, and that should leave
you with:
/emul/freebsd/usr/lib/libc.so.2.1
Finally, you must make sure that you have the FreeBSD runtime linker
and its config files on your system. You should copy these files
from the FreeBSD system to their appropriate place on your NetBSD
system (in the /emul/freebsd tree):
usr/libexec/ld.so
var/run/ld.so.hints
2. You don't have access to a FreeBSD system. In that case, you should
get the extra files you need from various ftp sites. Information on
where to look for the various files is appended below. For now,
let's assume you know where to get the files.
Retrieve the following files (from _one_ ftp site to avoid any ver-
sion mismatches), and install them under /emul/freebsd (i.e. foo/bar
is installed as /emul/freebsd/foo/bar):
sbin/ldconfig
usr/bin/ldd
usr/lib/libc.so.x.y.z
usr/libexec/ld.so
ldconfig and ldd don't necessarily need to be under /emul/freebsd,
you can install them elsewhere in the system too. Just make sure
they don't conflict with their NetBSD counterparts. A good idea
would be to install them in /usr/local/bin as ldconfig-freebsd and
ldd-freebsd.
Run the FreeBSD ldconfig program with directory arguments in which
the FreeBSD runtime linker should look for shared libs. /usr/lib
are standard, you could run like the following:
me@netbsd% mkdir -p /emul/freebsd/var/run
me@netbsd% touch /emul/freebsd/var/run/ld.so.hints
me@netbsd% ldconfig-freebsd /usr/X11R6/lib /usr/local/lib
Note that argument directories of ldconfig are mapped to
/emul/freebsd/XXXX by NetBSD's compat code, and should exist as such
on your system. Make sure /emul/freebsd/var/run/ld.so.hints is ex-
ist when you run FreeBSD's ldconfig, if not, you may lose NetBSD's
/var/run/ld.so.hints.
FreeBSD ldconfig should be statically linked, so it doesn't need any
shared libraries by itself. It will create the file
/emul/freebsd/var/run/ld.so.hints. You should rerun the FreeBSD
version of the ldconfig program each time you add a new shared li-
brary.
You should now be set up for FreeBSD binaries which only need a
shared libc. You can test this by running the FreeBSD ldd on itself.
Suppose that you have it installed as ldd-freebsd, it should produce
something like:
me@netbsd% ldd-freebsd `which ldd-freebsd`
/usr/local/bin/ldd-freebsd:
-lc.2 => /usr/lib/libc.so.2.1 (0x1001a000)
This being done, you are ready to install new FreeBSD binaries.
Whenever you install a new FreeBSD program, you should check if it
needs shared libraries, and if so, whether you have them installed
in the /emul/freebsd tree. To do this, you run the FreeBSD version
ldd on the new program, and watch its output. ldd (see also the
manual page for ldd(1)) will print a list of shared libraries that
the program depends on, in the form -l<majorname> => <fullname>.
If it prints "not found" in stead of <fullname> it means that you
need an extra library. Which library this is, is shown in <major-
name>, which will be of the form XXXX.<N> You will need to find a
libXXXX.so.<N>.<mm> on a FreeBSD ftp site, and install it on your
system. The XXXX (name) and <N> (major revision number) should
match; the minor number(s) <mm> are less important, though it is ad-
vised to take the most recent version.
Finding the necessary files.
Note: the information below is valid as of the ime this document was
written (Jun, 1995), but certain details such as names of ftp sites, di-
rectories and distribution names may have changed by the time you read
this.
FreeBSD distribution is available on a lot of ftp sites. Sometimes the
files are unpacked, and you can get the individual files you need, but
mostly they are stored in distribution sets, usually consisting of subdi-
rectories with gzipped tar files in them. The primary ftp sites for the
distributions are:
ftp.freebsd.org:/pub/FreeBSD
Mirror sites are described on:
ftp.freebsd.org:/pub/FreeBSD/MIRROR.SITES
This distribution consists of a number of tar-ed and gzipped files, Nor-
mally, they're controlled by an install program, but you can retrieve
files "by hand" too. The way to look something up is to retrieve all the
files in the distribution, and ``tar ztvf'' through them for the file you
need. Here is an example of a list of files that you might need.
Needed Files
ld.so 2.0-RELEASE/bindist/bindist.??
ldconfig 2.0-RELEASE/bindist/bindist.??
ldd 2.0-RELEASE/bindist/bindist.??
libc.so.2 2.0-RELEASE/bindist/bindist.??
libX11.so.6.0 2.0-RELEASE/XFree86-3.1/XFree86-3.1-bin.tar.gz
libX11.so.6.0 XFree86-3.1.1/X311bin.tgz
libXt.so.6.0 2.0-RELEASE/XFree86-3.1/XFree86-3.1-bin.tar.gz
libXt.so.6.0 XFree86-3.1.1/X311bin.tgz
The Files called ``bindist.??'' are tar-ed, gzipped and split, so you can
extract contents by ``cat bindist.?? | tar zpxf -''.
Extract the files from these gzipped tarfiles in your /emul/freebsd di-
rectory (possibly omitting or afterwards removing files you don't need),
and you are done.
BUGS
The information about FreeBSD distributions may become outdated.
NetBSD August 10, 1996 4