My notes on bootstrapping multilib on amd64

[Daniel Schepler <dschepler@gmail.com>]

Here are my notes on how to bootstrap multilib gcc and eglibc packages,
starting from a base without any multilib available.  I thought I'd post them
here in case anybody could benefit from them, or maybe had comments on how to
improve the process.

ln -s x86_64-linux-gnu /usr/include/x86_64-linux-gnux32
ln -s x86_64-linux-gnu /usr/include/i386-linux-gnu
touch /usr/include/x86_64-linux-gnu/gnu/stubs-{32,x32}.h

Start with gcc-4.7:
Edit debian/rules2
  Add --disable-libitm, --disable-libstdc++-v3 to disabled libs for
  DEB_STAGE build.
Edit debian/control.m4
  Remove ifenabled(`libx32gcc', ... condition from libx32gcc1 and
  libx32gcc-dev entries.
DEB_STAGE=stage1 DEB_BUILD_OPTIONS="parallel=? nocheck" dpkg-buildpackage -d -b -uc
dpkg -i --force-depends ../*.deb
  [as gcc-4.7-base isn't built but is still depended on; and also
   gcc-4.7-multilib still depends on libc6-dev-* which isn't built yet]

Next, eglibc:
Make sure make 3.81-8.2 is installed, and not 3.82-1 from experimental.
Edit /usr/share/perl5/Dpkg/Shlibs.pm and add /libx32 /usr/libx32 to
definition of DEFAULT_LIBRARY_PATH.
libc_cv_ssp=no DEB_BUILD_OPTIONS="parallel=? nocheck" dpkg-buildpackage -d -b -uc
rm /usr/include/x86_64-linux-gnux32 /usr/include/i386-linux-gnu \
  /usr/include/x86_64-linux-gnu/gnu/stubs-{32,x32}.h
dpkg -i ../{libc6,libc6-dev,libc6-i386,libc6-x32,
  libc6-dev-i386,libc6-dev-x32,locales,libc-bin,libc-dev-bin,
  multiarch-support,libc6-dbg}_*.deb
apt-get -f install [which will remove bootstrapped gcc-4.7 packages, but
  they're not needed anymore]

Now build gcc-4.8:
[For overall bootstrapping of Debian, can't build the Java part yet as:
 gcc-4.8 Build-Depends on libcairo2-dev
 cairo Build-Depends on libgl1-mesa-dev
 mesa Build-Depends on llvm-3.2-dev
 llvm-toolchain-3.2 Build-Depends on gcc-4.7
So, edit debian/rules.defs and add somewhere
  "with_java := disabled for bootstrap build"
I put it just above the line "ifeq ($(with_java),yes)".
]
DEB_BUILD_OPTIONS="parallel=? [nocheck]" dpkg-buildpackage -d -B -uc
dpkg -i ../lib32gcc1_*.deb ../libx32gcc1_*.deb ; resolve dependencies ; \
  apt-get check && dpkg --configure -a

Next, full version of gcc-4.7:
# reextract gcc-4.7 source package -- for some reason, the previous build
# put libantlr-java into the Build-Depends
DEB_BUILD_OPTIONS="parallel=? [nocheck]" dpkg-buildpackage -B -uc
dpkg -i ../g++-4.7_*.deb ../g++-4.7-multilib_*.deb ; resolve dependencies ; \
  apt-get check && dpkg --configure -a

Finally, full build of eglibc (with libssp usage compiled into the
appropriate utilities):
DEB_BUILD_OPTIONS="parallel=? [nocheck]" dpkg-buildpackage -b -uc
-- 
Daniel Schepler