For information on cross-compiling in general, see the chapter titled Cross Compilation Tools in The GNU configure and build system document.

If you are trying to compile 32-bit Firefox on a 64-bit Linux OS, you don't need to do a full cross-compile... see these simpler instructions.

Setting up a cross-compilation build environment

This isn't the end-all-be-all guide to setting up a cross-compilation build environment. WFM; YMMV. (If you have to ask "where do I get... or why doesn't 'X' work", then this isn't for you.)

For all of these examples, the following definitions are used:

You should add ${xprefix}/bin to your PATH.

Cross-compile binutils (if needed)

Download binutils and apply the binutils-cross-libpath.patch, which will make installing prebuilt libraries easier. Run configure using the following command:

env CROSS_LIB_PATH="${xprefix}/${xtarget_arch}/lib:${xprefix}/${xtarget_arch}/usr/lib" ./configure --prefix=${xprefix} --target=${xtarget_arch}

Build and install the package on the system.

Install target system headers and libraries

GCC and binutils will expect to find the system headers and libraries under ${xprefix}/${xtarget_arch} so you will need to copy those files from the target system, preserving directory structure and modify any scripts as necessary. You should copy over the X11 lib and include dirs as well.

If you already have rpms for the target system and rpm installed on the build system, then you can use this shortcut script which should install the rpms into $xprefix/$xtarget_arch using rpm2cpio.

Also, if you use Debian or Ubuntu, you can use dpkg-cross, apt-cross or Mutiarch to install the headers and libraries for target system.

To setup multi architecture support on Debian, see https://wiki.debian.org/Multiarch/HOWTO for more details.

Cross-compile gcc (if needed)

Some distributions already have cross compiling support such as g++-arm-linux-gnuabihf on Debian/sid.

But if you need build gcc from source code, download gcc and run configure with the following command:

./configure --prefix=${xprefix} --with-gnu-ld --with-gnu-as --target=${xtarget_arch} --disable-nls --enable-languages=c++,objc

Build and install the package on the system.

Verification

At this point, your cross-compilation environment should be completely set up. You should verify that it works. Start with Hello World and work your way up to a basic X11-based application.

For most packages, ./configure --target=${xtarget_arch} should be sufficient to build.

For others, you may have to explicitly set the build tools:

env AR=${xtarget_arch}-ar CC=${xtarget_arch}-gcc CXX=${xtarget_arch}-g++ LD=${xtarget_arch}-ld AS=${xtarget_arch}-as ./configure --prefix=${xprefix} --target=${xtarget_arch}

Cross-compile glib, gtk+ and etc

This step is only necessary if you did not install pre-built versions of these packages. Use the steps outlined above to build and install them.

Cross-compiling the lizard

Assuming that you properly setup your cross-compilation build environment as outlined above, cross-compiling Mozilla is fairly straightforward although NSS isn't properly setup to cross-compile (bug 104541).

The main thing to remember is that when --target=${xtarget_arch} is passed to configure, configure expects to find the compiler toolchain as ${xtarget_arch}-TOOL where TOOL is gcc, g++, ranlib, etc.

You must pass the following environment arguments to configure:

CROSS_COMPILE=1
export PKG_CONFIG_PATH=/path/to/target/system/lib/pkgconfig

and the following command line arguments to configure:

--target=${xtarget_arch}

Here's a sample mozconfig file used to cross-compile to the arm-linux-gnueabi target:

# sh
# Build configuration script
#
# See http://www.mozilla.org/build/unix.html for build instructions.
#
CROSS_COMPILE=1
export PKG_CONFIG_PATH=/usr/lib/arm-linux-gnueabi/pkgconfig

ac_add_options --prefix=/usr/lib/arm-linux-gnueabi
ac_add_options --target=arm-linux-gnueabi

# Options for 'configure' (same as command-line options).
# all are listed so that one can manually tweak this config file.
ac_add_options --enable-application=browser