[syslinux] Equivalent of pxechain.com for (USB key based) syslinux

[Jeffrey Hutzelman]

--On Friday, July 23, 2010 01:23:30 PM +0200 Alain Knaff 
<syslinux at misc.lka.org.lu> wrote:

> Hello list,
>
> I am trying to prepare a USB disk with syslinux that is meant to be able
> to offer a choice among many different distributions. The goal is that I
> should be able to dump each distribution's CD contents into a separate
> subdirectory, and have a master menu that hands off to each
> distribution's subdirectory.
>
> A while back, when faced with a similar task on a PXE server, I came
> across pxechain.com which elegantly solves this issue. With pxechain.com
> I can say the following in my master pxelinux.cfg/default:
>
> default menu.c32
> prompt 0
> menu title LGL PXE boot menu
> timeout 100
>
> LABEL KubuntuNet
>         menu Kubuntu network install
>         kernel pxechain.com
>         append ::kubuntu904/netboot/pxelinux.0
>
> LABEL udpcast
>         menu label Udpcast
>         kernel pxechain.com
>         append ::udpcast/pxelinux.0
>
> This correctly hands off to the (unmodified) pxelinux.cfg/default's in
> the distribution's subdirectories. All KERNELs and initrds now use the
> subdirectory (kubuntu904, udpcast) as their current directory, rather
> than the original root directory.
>
> However, how can I achieve the same thing with syslinux (for USB keys)?
> There is MENU INCLUDE, but it doesn't change the current directory, so
> the submenu file must be edited to prepend the subdirectory to every
> kernel, initrd, display, function key, further submenues, ...

Consider putting each distro's files into a floppy image, and using MEMDISK 
to boot the second-level SYSLINUX from the virtual floppy.

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+ at cmu.edu>
   Carnegie Mellon University - Pittsburgh, PA