Hacking Linux Kernel

Open a root shell. The following commands create a temporary directory and copy the files required for the booting of the Linux system (the isolinux boot loader as well as the kernel and the initrd) into it:
mkdir /tmp/CDroot
cp /usr/share/syslinux/isolinux.bin /tmp/CDroot/
cp /boot/vmlinuz /tmp/CDroot/linux
cp /boot/initrd /tmp/CDroot

Create the boot loader configuration file /tmp/CDroot/isolinux.cfg with your preferred editor. Enter the following content:
DEFAULT linux
LABEL linux
KERNEL linux
APPEND initrd=initrd root=/dev/hdXY [boot parameter]

Enter your root partition for the parameter root=/dev/hdXY. It is listed in the file /etc/fstab. Enter additional options for the setting [boot parameter], which should be used during booting. The configuration files could, for example, look like this:
DEFAULT linux
LABEL linux
KERNEL linux
APPEND initrd=initrd root=/dev/hda7 hdd=ide-scsi

The following command (entered at a command prompt) then creates an ISO-9660 file system for the CD.

mkisofs -r -o /tmp/bootcd.iso -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table /tmp/bootcd

-r is important to be case sensitive

The file /tmp/bootcd.iso can be written to CD after that with either graphical CD writing applications, like K3b