[syslinux] is substitution possible?

[H. Peter Anvin]

Wagner Ferenc wrote:
> 
> Yes.  That would amount to issue another DHCP request from the
> initramfs.  No big deal, but I somehow have the impression that it
> doesn't belong there.  But why do you mention the TFTP server?  It
> just serves the config file to PXELINUX, which could munge it to its
> liking, couldn't it?  Ehrm, would you accept patches for such
> functionality?

I would, assuming they're clean.  One way that has been discussed in the 
past is to do an HTTP to TFTP proxy server, another variant to execute 
from a program.

The big problem with all of this is that it has to be done quickly, 
because in the TFTP protocol there is no way to distinguish a request 
retry from a second request, which could flood the server very quickly 
if substitution is slow.  In order to support the "tsize" option, which 
PXELINUX requires, one has to have the total transfer size ready before 
transfer can begin.

	-hpa