NAME
compat_freebsd —
setup procedure for
running FreeBSD binaries
DESCRIPTION
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.
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).
- You have access to a
FreeBSD system. In this case you can temporarily
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 access 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 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:
- /emul/freebsd/usr/lib/libc.so.2.0
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:
- /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
- 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 version
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 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.
- In some cases,
FreeBSD binary needs access to certain device
file. For example, FreeBSD X server software needs
FreeBSD /dev/ttyv0 for ioctls.
In this case, create a symbolic link from
/emul/freebsd/dev/ttyv0 to a
wscons(4) device file like
/dev/ttyE0. You will need to have at least
options WSDISPLAY_COMPAT_SYSCONS and probably also
options WSDISPLAY_COMPAT_USL in your kernel (see
options(4) and
wscons(4)).
Finding the necessary files
Note: the information below is valid as of the time this
document was written (June, 1995), but certain details such as names of ftp
sites, directories and distribution names may have changed by the time you
read this.
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.
BUGS
The information about
FreeBSD distributions may become
outdated.