[syslinux] Problems with multiboot DVD and isolinux > 3.07

[Christian Schneider]

Hi,

some time ago I tried to boot an isolinux boot loader from another one 
to be able to boot e.g. a Knoppix CD with its original boot loader and 
menus from a "main" isolinux on a multiboot DVD.

This works for isolinux <= 3.07 now!

However, newer isolinux boot loaders have some problems and the isolinux 
(e.g. of the Knoppix CD) loaded from the multiboot DVD's main isolinux 
(> 3.07) freezes for some reason.

As an example I want to tell you how I integrated Knoppix to my 
multiboot DVD:
1. I "installed" isolinux (3.07) into dvd_root/boot/isolinux with config 
and menus (refered to as "main isolinux")
2. I copied the /KNOPPIX directory from the Knoppix CD to dvd_root/ and
the /boot/isolinux directory from the Knoppix CD to
dvd_root/boot/knoppixo (this boot loader will be refered to as 
"secondary isolinux")
3. I changed the config search dir of
dvd_root/boot/knoppixo/isolinux.bin to its new directory
4. I created a 2KB file called dvd_root/boot/bootsec/knoppixo.bin (which 
is loaded from the main isolinux when selecting Knoppix)
5. I created the ISO9660 image
6. I wrote the boot info table to /boot/knoppixo/isolinux.bin (in the 
ISO9660 image!) and copied the first 2KB of /boot/knoppixo/isolinux.bin 
to /boot/bootsec/knoppixo.bin (in the ISO9660 image!) using a 
home-brewed tool

As already mentioned, everything works for isolinux <= 3.07. After some 
unsuccesful DVDs using a newer isolinux version, I used qemu to test 
the DVD before burning it. Using isolinux 3.08 as main isolinux only 
some secondary isolinux boot loaders freeze, with 3.09 all secondary 
isolinux loaders freeze and with newer versions qemu crashes totally.

If you are interested in the problem (and my tool), please let me know.

Cheers,
Christian