| COMPAT_FREEBSD(8) | System Manager's Manual | COMPAT_FREEBSD(8) | 
compat_freebsd —
NetBSD supports running
    FreeBSD binaries. Most binaries should work, except
    programs that use FreeBSD-specific features. These
    include i386-specific calls, such as syscons utilities. 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 naming 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.
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:
Note that if you already have a
        FreeBSD shared library with a matching 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 system:
and you find that the ldd output for a new binary you want to install 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, because 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:
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):
Retrieve the following files (from _one_ ftp site to avoid any version mismatches), and install them under /emul/freebsd (i.e. foo/bar is installed as /emul/freebsd/foo/bar):
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 existing
        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 library.
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” instead of <fullname> it means that you need an extra library. Which library this is, is shown in <majorname>, 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 advised to take the most recent version.
options WSDISPLAY_COMPAT_SYSCONS and probably also
      options WSDISPLAY_COMPAT_USL in your kernel (see
      options(4) and
      wscons(4)).The 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 subdirectories with gzipped tar files in them. The ftp site for the distributions is: ftp://ftp.FreeBSD.org/pub/FreeBSD
This distribution consists of a number of tar-ed and gzipped files, Normally, 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 directory (possibly omitting or afterwards removing files you don't need), and you are done.
| February 10, 2018 | NetBSD 10.1 |