[[meta copyright="Copyright © 2007 Free Software Foundation, Inc."]] [[meta license="Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled [[GNU_Free_Documentation_License|/fdl]]."]] # `cross-gnu` [[Thomas_Schwinge|tschwinge]] has written a shell script for building a complete cross-build environment for GNU/Hurd systems. For now, find the shell scripts at and . ## Using Read through it. Understand it. Only then use it by following the next steps. /!\ Be made aware that -- while it is of course possible to build a working cross-compiler -- this is not trivial to do. You'll have to patch source packages. See the following list about needed patches, which have not yet been installed in the upstream repositories. ### Supported Versions of Source Packages The following ones are known to work. Others may work as well, but no guarantee is given. Always the preferred version is listed first. * `src/binutils`: [[GNU_Binutils|binutils]] * CVS `binutils-2_18-branch` $ mkdir binutils-2_18-branch $ cd binutils-2_18-branch $ cvs -d:pserver:anoncvs@sources.redhat.com:/cvs/src \ co -r binutils-2_18-branch binutils The sources are rooted in `binutils-2_18-branch/src/`. Also use these commands for updating, instead of the usual `cvs update`. * The 2.18 release tarball from should also be fine, as should be all other recent releases. * `src/gcc`: [[GNU_Compiler_Collection|gcc]] * SVN `gcc-4_1-branch` $ svn co svn://gcc.gnu.org/svn/gcc/branches/gcc-4_1-branch Prepare: $ ( cd gcc-4_1-branch/ && contrib/gcc_update --touch ) * Recent releases of the 4.1 series from should also be fine. * SVN `gcc-4_2-branch` $ svn co svn://gcc.gnu.org/svn/gcc/branches/gcc-4_2-branch Prepare: $ ( cd gcc-4_2-branch/ && contrib/gcc_update --touch ) * Patches: * Recent releases of the 4.2 series from should also be fine, but need the same set of patches as the `gcc-4_2-branch` needs. Support for the upcoming 4.3 series (`trunk`) is being worked on. * `src/gnumach`: [[GNU_Mach|microkernel/mach/gnumach]] * CVS `gnumach-1-branch` $ cvs -d:pserver:anoncvs@cvs.gnu.org:/cvsroot/hurd \ co -r gnumach-1-branch gnumach $ mv gnumach gnumach-1-branch Prepare: $ ( cd gnumach-1-branch/ && autoreconf -vfi ) * `src/mig`: [[GNU_Mach_Interface_Generator|microkernel/mach/mig]] * CVS `HEAD` $ cvs -d:pserver:anoncvs@cvs.gnu.org:/cvsroot/hurd co mig Prepare: $ ( cd mig/ && autoreconf -vfi ) * `src/hurd`: [[GNU_Hurd|hurd]] * CVS `HEAD` $ cvs -d:pserver:anoncvs@cvs.gnu.org:/cvsroot/hurd co hurd * `src/glibc`: [[GNU_C_Library|glibc]] * CVS `glibc-2_7-branch` $ cvs -d:pserver:anoncvs@sources.redhat.com:/cvs/glibc \ co -r glibc-2_7-branch glibc $ mv libc glibc-2_7-branch * Patches: * Recent releases of the 2.7 series from should also be fine, but need the same set of patches as the `glibc-2_7-branch` needs. ### Preparation Unpack the tarballs if you downloaded any. Create a directory where the cross build shall be rooted in and a `src` subdirectory in there. Then create symbolic links for every of the above packages: from `src/PACKAGE` to where you stored or unpacked it. If you don't intend to build several cross compilers or use the source trees otherwise, you can also directly store the source trees in `src/`. The source trees can be shared between multiple cross build trees since the packages' build systems are supposed not to modify the files in the source trees. Not all packages adhere to that, but they fail to do so only for pre-processed documentation, etc. Either make sure that `cross-gnu-env` and `cross-gnu` are found in `$PATH` (`~/bin/`, for example) or alternatively remember to use their full paths in the following. The system you're running the script on (the *build* system) needs to have a basic compiling environment installed, i.e., a C compiler with the basic libraries and `make`. You might also need `flex` and `bison`. For building recent version of GCC (e.g., the upcoming 4.3, which is not yet supported) you'll need to have development packages of GMP and MPFR installed. ### Setting Up the Environment Do this every time you intend to use the cross compiler: $ ROOT=to/the/cross/build/root $ . cross-gnu-env This will set several environment variables, which are later used by (a) the `cross-gnu` script and (b) by you, the user of the cross compiler. `$TARGET` will be set by the script, `$PATH` will be adjusted, etc. See the `cross-gnu-env` file for all environment variables that are set, as well as their default values. `$ROOT` will be made an absolute path if it isn't already. Later, you'll be able to do things like `../configure --host="$TARGET"` and the cross compiler will be found automatically. ### Creating the Cross Build Environment After setting up the environemt, just run `cross-gnu` and watch the messages flow by. In the end you should see a message: *[...]/cross-gnu: Everything should be in place now.* ### Makefile The following Makefile has been written to automate the above steps. You will require Internet connection and atleast 1.5 GB of hard-disk spaace. Just run: 
  make
to build the toolchain. To clean-up, use: 
  make clean
### Staying Up-To-Date You can re-run `cross-gnu` to rebuild the parts of the sources that have changed since the last run. This will save a lot of time compared to starting from scratch again. Also, it is especially useful if you aren't working with unpacked tarballs, but on CVS's branches or want to quickly get a new tool chain with patches you applied to the source trees. However: do *not* use this technique when doing major changes to the source trees, like switching from GCC 4.0 to GCC 4.1. #### Comment Unfortunately the GNU Automake build system (which is used by GNU Mach's `gnumach-1-branch`) will overwrite installed files (header files in this case here), even if they didn't change. And because all packages' build systems are using dependency tracking, a lot of files will be rebuilt each time `cross-gnu` is re-run, even if the files themselves didn't change. Talk to [[tschwinge]] if you want to work on fixing that -- it is already clear what needs to be done, it just hasn't been done yet. # References *