Debootstrap Ubuntu from Gentoo
From NAS-Central Buffalo - The Linkstation Wiki
The original way of installing Ubuntu is to use a temporary installation of Debian. This small guide is for people who already have a running system, such as Gentoo.
First, prepare your target partition with 'fdisk' and 'mkfs.ext3'. I'll assume your target partition is mounted at /mnt/ubuntu/
Now emerge debootstrap:
$ sudo emerge -av debootstrap
By default, debootstrap only has package information for Debian, not for Ubuntu. We'll need to get the Ubuntu equivalent:
$ sudo su - # cd /usr/lib/debootstrap/scripts/ # wget http://insignificant.org/wp-content/2007/12/gutsy.zip # tar -xzvf gutsy.zip
Now start the debootstrap:
# debootstrap --arch powerpc gutsy /mnt/ubuntu http://archive.ubuntu.com/ubuntu/
Then continue according to the Ubuntu using temporary Debian guide.