Exemplo usando o Knoppix.
create a mountpoint to mount the ISO with loopback:
mkdir /mnt/LiveISO
mount the image:
mount -t iso9660 -o loop,ro /DOWNLOADS/Knoppix-3.7-en.iso /mnt/LiveISO
create a directory on the device where you are going to boot from:
mkdir /mnt/hda4/KNOPPIX
copy the contents of the mounted image to that directory:
cp /mnt/LiveISO/KNOPPIX/* /mnt/hda4/KNOPPIX/
copy kernel and initrd files to yor boot device:
cp /mnt/LiveISO/boot/* /boot
Grub:
title KNOPPIX root (hd0,0) kernel /linux26 ramdisk_size=100000 fromhd=/dev/hda4 initrd /minirt26.gz savedefault boot
Lilo:
image=/boot/linux26 initrd=/boot/minirt26.gz label=KNOPPIX append="ramdisk_size=100000 fromhd=/dev/hda4"
The basic idea is that you copy the contents of the iso to a partition. Then, in your current linux os, you copy the kernel and initrd images from the iso to your current boot directory. Last, you edit LILO so that it points to the kernel and initrd images you just copied, and make sure you append the "fromhd" line so that the "livecd" will know where the rest of the knoppix files are. I know that similar instructions worked with kanotix as well (which makes sense since it is knoppix based). The only possible problem for other isos (say non-livecds, for example) is that they may not have a "fromhd" option the way knoppix distros do.
Encontrado aqui: Imagem ISO de inicialização do disco rígido?