## Building the base image
This documents exactly what I did step by step. As I had some small mis-steps, it's longer than needs to be. When I give it another go, I'll condense it to the bare minimum.

First use debootstrap to generate a chrootable rootfs. We do this on any speedy machine (faster to do the dependency calculation there) and do the next bit on the raspi.

    sudo debootstrap \
    --include=ssh,python,lua5.1,build-essential,lxde,sudo,locales,xserver-xorg,bash-completion \
    --components=main,contrib,non-free \
    --verbose \
    --foreign --arch armel \
    sid sid_rootfs http://www-uxsup.csx.cam.ac.uk/pub/linux/debian

Now tar that over the network to the raspberry pi

    sudo sh -c "tar -cpf - sid_rootfs | ssh user@raspi sudo tar -xpf -"

Then, on the raspi:

    cd sid_rootfs
    sudo chroot .
    ./debootstrap/debootstrap --second-stage
    apt-get clean # get rid of downloaded .debs


You know longer need to be in the chroot, but might prefer to be.

Configure `etc/fstab`:


    cat <<EOF > etc/fstab
    proc            /proc           proc    defaults          0       0
    /dev/mmcblk0p1  /boot           vfat    defaults          0       0
    /dev/mmcblk0p2  /               ext3    defaults,noatime  0       0
    /dev/mmcblk0p3  none            swap    sw                0       0
    EOF


Configure  `etc/apt/sources.list`

    cat <<EOF > etc/apt/sources.list
    deb http://www-uxsup.csx.cam.ac.uk/pub/linux/debian sid main contrib non-free
    deb-src http://www-uxsup.csx.cam.ac.uk/pub/linux/debian sid main contrib non-free
    EOF


Configure `etc/network/interfaces`:

    echo "auto usb0" >> etc/network/interfaces
    echo "iface usb0 inet dhcp" >> etc/network/interfaces

Now set up hostname:

    export NEWHOSTNAME=blank # or whatever you want
    echo $NEWHOSTNAME > etc/hostname
    printf "127.0.1.1\t$NEWHOSTNAME\n" >> etc/hosts


Now copy `/lib/modules/*` from root fs and set up vchiq:

    cp -a /lib/modules/* lib/modules
    echo vchiq >> etc/modules
    cp -a /etc/init.d/vchiq etc/init.d/
    chroot .
    inserv /etc/init.d/vchiq
    exit


The image now *should* be bootable. Tar it over the network, compress it,
archive it. On the computer connected to the raspi do:

    ssh eupton@10.42.43.40 sudo tar -cpf - -C sid_rootfs . | bzip2 --best > rootfs_sid_armel_blank_20_09_11.tar.bz2

Now we can rewrite card and boot the new system, then do the post-system
setup.

Edit `/etc/shadow` and remove the `*`. Now
you can log in as root with no password.