Ubuntu Wiki

Make sure you have all the necessary dependencies

sudo apt-get build-dep gfxboot-theme-ubuntu
sudo apt-get install gfxboot unifont

Branch gfxboot-theme-ubuntu and update it

bzr branch lp:~ubuntu-core-dev/localechooser/ubuntu ~/bzr/localechooser.ubuntu
bzr branch lp:~ubuntu-core-dev/gfxboot-theme-ubuntu/mainline ~/bzr/gfxboot-theme-ubuntu.trunk
cd ~/bzr/gfxboot-theme-ubuntu.trunk
sudo ./scrape-console-setup > keytables.inc
sudo ./scrape-localechooser ~/bzr/localechooser.ubuntu > langnames.inc

Update the font

(cd /tmp; apt-get source debian-installer)
make
DI_PATH=/tmp/debian-installer-* make font

Build and extract

debuild
dpkg -x ../gfxboot_theme_ubuntu*.deb /tmp
mv /tmp/usr/share/gfxboot-theme-ubuntu /tmp

Test

cd /tmp
wget http://people.canonical.com/~cjwatson/tmp/gfxboot-test.tar.gz
tar zxvf gfxboot-test.tar.gz
cd test
make