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

[H. Peter Anvin]

On 07/23/2010 04:23 AM, Alain Knaff 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, ...
> 

CONFIG supports this in Syslinux 4:

LABEL subdir
	CONFIG subdir/syslinux.cfg
	APPEND subdir

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.