Cross Compiling

Builder

Builder is a vserver that is used to build cross-compilers and cross-packages that run on x86_64 machines. The current list of installed cross-compilers includes alpha, arm, hppa (binutils only), i486, ia64, m68k, mips, mipsel, powerpc, sparc and x86_64. www.emdebian.org builds a number of cross-compilers, which can be installed by adding the following lines to /etc/apt/sources.list:

deb http://mirror.csclub.uwaterloo.ca/emdebian/ stable main
deb-src http://mirror.csclub.uwaterloo.ca/emdebian/ stable main

Debian-supported Architectures

Initial setup:

export PREFIX=architecture (target architecture gcc prefix: arm, i486, x86_64, etc...)
export DEB_ARCH=architecture (target architecture debian name: arm, i386, amd64, etc...)
sudo apt-get install apt-cross dpkg-cross autoconf automake gawk flex bison debhelper devscripts cdbs fakeroot
apt-cross -a $DEB_ARCH -i linux-kernel-headers libc6 libc6-dev

Binutils:

apt-get source binutils gcc-4.1
cd binutils and run:
TARGET=$PREFIX-linux-gnu fakeroot debian/rules binary-cross
sudo dpkg -i binutils-$PREFIX-linux-gnu_*.deb

GCC:

cd gcc-4.1 and run:
export GCC_TARGET=$DEB_ARCH
export DEB_CROSS_INDEPENDENT=yes
export WITHOUT_LANG=java,fortran,pascal,obj,obj-c++,ada,treelang
export DEB_CROSS_NO_BIARCH=yes
export USE_NJOBS=$(echo $(cat /proc/cpuinfo | grep ^processor | wc -l)*2 | bc)
export DEBUILD_PRESERVE_ENVVARS=GCC_TARGET,DEB_CROSS_INDEPENDNET,WITHOUT_LANG,DEB_CROSS_NO_BIARCH,USE_NJOBS
debuild -rfakeroot -k$USER
sudo dpkg -i gcc-4.1-*.deb

It's generally useful to upload these built packages to the CSC debian repository. To do this you need to scp the .deb's over to debian.csclub and run 'rrr-includedeb deb-files...'.

Debian Cross-packages

There are a few tools that are useful for building cross-packages:

• emdebuild: an architecture aware version of debuild.
• dpkg-cross: a version of dpkg that allows you to install architecture-specific libraries in an isolated way. For example, dpkg-cross will build a package called libc6-mips-cross from the mips libc6 package. This cross package can then be installed alongside the mips cross-compiler.
• apt-cross: a front-end to dpkg-cross. It will automatically fetch and build cross packages.

SPARC Solaris 8 (student environment)

Initial setup:

export TARGET=sparc-sun-solaris2.8
export PREFIX=/opt/$TARGET-toolchain
mkdir $PREFIX
export WORKDIR=/tmp/$TARGET-toolchain
mkdir $WORKDIR
export PATH=$PREFIX/bin:$PATH

Fetch Solaris includes/libs:

cd $WORKDIR
rsync -av --copy-unsafe-links cpu20.student.cs.uwaterloo.ca:/usr/lib/ lib
* lib is ~ 1100 MiB
rsync -av --copy-unsafe-links cpu20.student.cs.uwaterloo.ca:/usr/include/ include
* include is ~ 100 MiB

Binutils:

cd $WORKDIR
wget http://ftp.gnu.org/gnu/binutils/binutils-2.18.tar.bz2 && tar -xjf binutils-2.18.tar.bz2
mkdir $WORKDIR/build-binutils && cd $WORKDIR/build-binutils
../binutils-2.18/configure --target=$TARGET --prefix=$PREFIX
make -j4 && make install

GCC-3.4:

cd $WORKDIR
wget http://ftp.gnu.org/gnu/gcc/gcc-3.4.6/gcc-3.4.6.tar.bz2 && tar -xjf gcc-3.4.6.tar.bz2
mkdir $WORKDIR/build-gcc-3.4 && cd $WORKDIR/build-gcc-3.4
../gcc-3.4.6/configure --target=$TARGET --prefix=$PREFIX --enable-languages=c,c++ --with-gnu-ld --with-gnu-as --enable-shared \
  --disable-multilib --enable-threads=posix --enable-long-long --with-headers=$WORKDIR/include --with-libs=$WORKDIR/lib
make -j4 && make install

Notes:

• In order to get gcc to compile, I had to modify $WORKDIR/build-gcc-3.4/gcc-3.4.6/gcc/config/sparc/gmon-sol2.c by replacing PATH_MAX with 1024.
• When you compile g++, libstdc++.so.6 gets compiled and installed, which causes libstdc++.so to be symlinked to libstdc++.so.6. However, the student environment doesn't include libstdc++.so.6. You can fix this by changing the symlink to libstdc++.so.5:

rm $PREFIX/$TARGET/lib/libstdc++.so && ln -s libstdc++.so.5 $PREFIX/$TARGET/lib/libstdc++.so