KubuntuAlternateUsbNetBoot

This small Tutorial shows you how to set up a small CD that allows you to install Kubuntu via USB or via the net. This is useful for old machines which neither support USB nor Net boot natively, but whose CD-Rom drive may be too old and faulty to afford an installation entirely by CD.

The boot image generate herein is small enough to fit in just 16 Megs. Even old drives should still be able to read images that small.

Preparing the CD

1. Make the CD by copying the install and isolinux directories
2. Run the mkInitrd script (see below) of this directory to merge vfat into the image
3. Move install/netboot/ubuntu-installer/i386/initrd.gz to install/initrd-net.gz under the CD
4. install/netboot can now be removed...
5. Edit isolinux to add lines to boot from net (just use standard lines and substitude initrd.gz with initrd-net.gz
6. Run the mkImage script

Preparing the USB stick (not bootable)

1. Copy everything on CD to the USB stick formatted as VFAT
2. As the Vfat filesystem does not support symlinks, copy the gutsy directory to stable

Making the USB bootable

1. (If not yet done) Make a single partition on the flash drive, and make it bootable
2. mkfs.vfat -F16 -n ubuntu710 /dev/sdx1
3. syslinux -sf /dev/sdx1
4. mount /dev/sdx1 /media/ubuntu710
5. cp -a $CD/ /media/ubuntu710
6. Make sure the .disk/info directory has been copied
7. cd /media/ubuntu710
8. cp -a dists/gutsy dists/stable
9. cp $BUILD/image/install/initrd.gz install/ (where BUILD is the path to your initrd.gz . Example BUILD=alain/VirtualMachines/CdUsbBuntu)
10. Copy isolinux/isolinux.cfg to syslinux.cfg and remove all GFXBOOT , menu and f* (function key help) lines
11. If needed: lilo -M /dev/sdx

mkInitrd script

In this script, the cd= line needs to be changed to point to a directory where a standard Kubuntu Alternate CD is mounted.

#!/bin/sh

cd=$HOME/Download/7.10

DIR=`dirname $0`
cd $DIR

if [ -d initrd ] ; then
   rm -rf initrd
fi

mkdir initrd
cd initrd
# As root, uncpio initrd
zcat ../image/install/initrd.gz | cpio -i --make-directories

# Unpack vfat:
kernel=`ls lib/modules`

ar p $cd/pool/main/l/linux-source-*/fat-modules-$kernel-di_*_i386.udeb data.tar.gz | tar xfzv -

# Re-run depmod to include new module
depmod -b .

# Patch cdrom-detect script to detect USB sticks instead
sed -e 's/list-devices cd/list-devices partition/g' \
    -e 's/iso9660/vfat/g' \
    -e 's/\(\t*\)\(log "CD-ROM mount succeeded: device=.device"\)/\1if [ ! -e \/cdrom\/.disk\/info ] ; then umount \/cdrom ; continue; fi\n\1\2/' \
    var/lib/dpkg/info/cdrom-detect.postinst > var/lib/dpkg/info/usb-detect.postinst
chmod 755 var/lib/dpkg/info/usb-detect.postinst
mv var/lib/dpkg/info/usb-detect.postinst var/lib/dpkg/info/cdrom-detect.postinst


# Pack it up
find . -print | cpio -H newc -o | gzip -9 >../image/install/initrd.gz

mkImage script

#!/bin/sh

cd `dirname $0`/image

mkisofs -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -J -hide-rr-moved -V "Net&USB Boot CD" -o ../boot.iso -R .