Provided by: dpkg-cross_2.6.15-3ubuntu1_all 
Name
dpkg-cross - manage libraries for cross compiling
Copyright and Licence
Copyright (C) 1997-2000 Roman Hodek <roman@hodek.net>
Copyright (C) 2000-2002 Colin Watson <cjwatson@debian.org>
Copyright (C) 2002-2004 David Schleef <ds@schleef.org>
Copyright (C) 2004 Nikita Youshchenko <yoush@cs.msu.su>
Copyright (C) 2004 Raphael Bossek <bossekr@debian.org>
Copyright (c) 2007-2011 Neil Williams <codehelp@debian.org>
Copyright (c) 2011 Wookey <wookey@debian.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
SYNOPSIS
dpkg-cross [OPTIONS] [--install|-i] <files...>
dpkg-cross [OPTIONS] [--build|-b] <files...>
dpkg-cross [OPTIONS] [--remove|--purge|-r] <packages...>
dpkg-cross [OPTIONS] [--status|-s] <packages...>
dpkg-cross [OPTIONS] [--list|-l] <packages...>
dpkg-cross [OPTIONS] [--list-files|-L] <packages...>
dpkg-cross [OPTIONS] [--query|-Q] <pkgpath>
dpkg-cross [OPTIONS] [--update|-u] <pkgpath>
OPTIONS: [ -v | --verbose ] [ -q | --quiet ]
{ [ -a | --arch ] architecture } { [ -X | --exclude ] PACKAGE }
[ -A | --convert-anyway ] [ -M | --convert-multiarch ] [ -k | --keep-temp ]
DESCRIPTION
dpkg-cross is a tool to install and manage libraries and header files for cross compiling. dpkg-cross
converts native Debian packages for the target architecture to cross compiling support packages that can
be installed on any architecture, but in different paths to avoid conflicts. It then calls dpkg to
install the converted package. The conversion step alone can be done with the --build option. Other
options are wrappers around corresponding dpkg functionality.
dpkg-cross is intended to make it easier for you to keep your cross compiling libraries up-to-date, as it
works directly on Debian packages. It saves you copying the libs and headers from a machine with your
target architecture, or extracting them via dpkg-deb --fsys-tarfile.
dpkg-cross also collects and install the .shlibs files in -dev packages, which are needed by dpkg-
shlibdeps.
CMAKE
CMake cross-building support is experimental!
CMake requires a little support from dpkg-cross to cross-build. The included cmake support file is an
example for Linux kernels. Use:
rm CMakeCache.txt
cmake -DCMAKE_TOOLCHAIN_FILE=/etc/dpkg-cross/cmake/CMakeCross.txt
The main changes involve setting PKG_CONFIG_LIBDIR within CMake an setting the include directories to
locate the cross libraries installed by dpkg-cross e.g.
#Make pkg-config look in the right place
SET(ENV{PKG_CONFIG_LIBDIR} ${CMAKE_FIND_ROOT_PATH}/lib/pkgconfig/)
ELSE (CMAKE_CROSSCOMPILING)
Packages using cmake may need some tweaks to debian/rules, e.g.
ifneq ($(DEB_HOST_GNU_TYPE),$(DEB_BUILD_GNU_TYPE))
export CC=$(DEB_HOST_GNU_TYPE)-gcc
export CXX=$(DEB_HOST_GNU_TYPE)-g++
export CMAKE_TOOLCHAIN_FILE=/etc/dpkg-cross/cmake/CMakeCross.txt
else
export CC=gcc
export CXX=g++
endif
OPTIONS
dpkg-cross follows the usual GNU command line syntax, with long options starting with two dashes ('-').
-h|--help
Show summary of options.
-v|--verbose
Be more verbose.
-q|--quiet
Be more quiet.
-a|--arch architecture
Install for architecture architecture.
-i|--install
Install Debian packages (.deb) named on the command line. Only files in the directories /lib, /usr/lib
and /usr/include are extracted, since only they can be relevant for cross compiling. In the lib
directories, also no subdirectories are extracted.
-A|--convert-anyway
Convert Debian package even if it does not provide any files useful for cross-compile environment.
-M|--convert-multiarch
Convert package even if it is a multiarch package. If the package is not a multiarch package, processing
continues as normal.
-X|--exclude PACKAGE
Removes the specified package from the dependencies of the current package. Typically used to drop
dependencies on packages that are not required within a cross-build environment, e.g. packages containing
only executables or architecture independent files.
dpkg-cross can only check the current package and information about a dependency is not available (for
that, use xapt). By default, dpkg-cross converts all dependencies to specify the cross version of the
dependency package.
If you know that a particular dependency should not be converted (it provides no useful files or is
architecture independent), that dependency can be excluded and dpkg-cross will remove that package from
the dependency information of the cross package. -X has replaced the use of keepdeps and removedeps in
/etc/dpkg-cross/cross-compile.
-X|--exclude PACKAGE needs to be repeated for each package to be excluded.
-k|--keep-temp
Keep the built and installed package instead of deleting it. Requires --install.
-b|--build
Just build the converted Debian package, but do not install it with dpkg.
-r|--remove
Remove the cross compiling packages named on the command line.
-s|--status
Print status of the named packages.
-l|--list
Print short version of status of named packages or package name patterns.
-L|--list-files
List files belonging to the named packages.
-u|--update
Update current cross-installation with Debian packages found in/under the paths given as arguments. Will
check all packages there if they are installed already as cross-compiling packages and if they are really
updates. Those packages will be installed as with -i.
-Q|--query
Much like --update, but just prints available update packages and does not install them.
FILES
/etc/dpkg-cross/cross-compile defines the default_arch for dpkg-cross:
The default architecture for dpkg-cross is normally set by debconf. To change the system-wide value,
use:
$ sudo dpkg-reconfigure dpkg-cross
Alternatively, the default can be overridden on a per-user basis using the optional file in
$HOME/.dpkg-cross/
Conversion process
There is no safe way for dpkg-cross to mangle certain files in -dev packages, particularly files in
/usr/share or to determine precisely which of these files could be parsed and which cannot. Special cases
do not help - dpkg-cross already has too many of those.
It is not safe to leave files in the package nor is it safe to move files into arbitrary locations when
there is no reliable and standardised way to determine the usefulness of a particular kind of file.
Package specific config scripts cannot be supported and even build-system specific ones are not
necessarily going to work without a lot of ongoing maintenance.
Therefore, "dpkg-cross" is very restrictive on which files are retained in the -cross package.
Files to be converted
All files in
/usr/include/*
Also /usr/src and /usr/lib are searched for includes - files with .h, .hh, .hpp extensions (case
insensitive).
Library files - *.so* and *.a and *.o files from /lib and /usr/lib (and all the multilib eqivalents
(lib64, lib32, libo32, libhf, libx32 etc). Other library files are not copied. *.la files in library
directories are also copied, and library and paths are modified there. Same for /usr/lib/pkgconfig/*.pc
files.
Symlinks are copied (and modified appropriately) if their destination is copied. Also, symlinks to non-
existing shared libraries are copied (this is common case for libdevel packages)
Directories are created only to hold some files or symlinks. No empty directories are copied.
Multiarch behaviour
By default <dpkg-cross> does nothing with packages from Debian which already support Multi-Arch - the
package is simply copied to the current work directory, if it does not already exist. Any package
containing a Multi-Arch: field in DEBIAN/control is skipped in this manner.
--convert-multiarch can be specified to instead force the generation of a -<arch>-cross package with the
files moved into the conventional dpkg-cross locations.
The Multiarch spec ensures that multiarch packages will only be available from Debian mirrors once dpkg
itself is capable of installing the packages and installing a Multiarch package means being able to
install a 32bit multiarch package alongside a 64bit multiarch package. Installing an armel multiarch
package alongside an x86 multiarch package is no different to 32bit vs 64bit. (What changes is how the
multiarch package itself handles the header files and pkg-config files.)