Introduction

'cross-hurd' is a set of scripts for building a toolchain for cross-compiling the GNU Hurd operating system. The scripts will download the sources, compile all the packages required for building a cross-compiler and then compile a very basic operating system that is bootable using Qemu or other virtual machine.

It has been tested on Linux and does not appear to work on Mac OS X due to problems when building the Glibc.

Downloading all the sources

The first step is to download all the required sources. Run "bash download.sh" to download all the required packages. The build system will use the most up-to-date gnumach, glibc, libpthread, mig and hurd packages by fetching them from the official git repositories available on http://git.savannah.gnu.org/cgit/hurd/.

Building a toolchain

First, update the CC and CXX variables in "vars.sh" to match your architecture and GCC version.

To build the cross-compiler, run "bash bootstrap.sh". The script will create a build environment on the $PWD/tmp directory. Two directory links, "/tools" and "/cross-tools" will be created: "/cross-tools" is a link to $PWD/tmp/cross-tools and contains the cross-compiler; "/tools" will contain the basic system and points to $PWD/tmp/tools. You will be asked for the root password for some steps in the process since we are creating links in the root file system.

Note that you need to install GCC, make, flex, bison, and other related packages in order to build the cross tools.

Compiling the basic system

Once the toolchain is in place, run "bash compile.sh" to build a very basic set of packages using the cross-compiler built on the previous phase. Everything is installed into $PWD/tmp/tools.

Creating a bootable disk image

If everything went alright, then run "bash create-image.sh" to create a bootable disk image. You will be asked for a sudo password because you need access to the loopback device. The script will use the base system built previously. The script runs 'grub-install' on the final disk image and needs to have the files for the i386-pc architecture (in debian, you need to install grub-pc-bin).

Once the file "hd.img" is in place, just run it on your favorite virtual machine. The grub bootloader will load GNU Mach and the Hurd and complete the installation process by populating the /dev directory, setting an empty password for the root user and then rebooting. Afterwards, just enter "login root" and an empty password to log into the system.