Syslinux - Feb 2003 - Q: passing DHCP options to the booted linux-kernel?

Hello everybody!


I'm using pxelinux to boot my kernel. I'd like to pass the DHCP values
to the
kernel (router, ip-address, ...) so that the kernel can use it without having 
to obtain a new lease.

I've searched the mailing list and the net and found the DHCP option to 
specify other configfiles, but I couldn't find out how to make pxelinux pass
the dhcp values to the kernel (eg APPEND='dhcp_ip=$ip
dhcp_router=$router'
and so on).

Is this possible?


BTW, I'm not subscribed to the list, so please cc me.
Thank you!


Regards,

Phil

> Any results ?
Yes.

There's a parameter in the pxelinux-configuration file which gets loaded via
tftp named "IPAPPEND". If it is set to a value of 1, pxelinux passes a
parameter "ip=..,..,..,..." to the kernel - can't remember just
know which
value order. 

The linux kernel has a compile option named "ip autoconfiguration".
With this compiled in it looks for a "ip"-parameter, and depending on
other
settings, does DHCP, RARP or even PXE (or something other - there were 3 
options) on the interfaces.

What I didn't find was how to specify the interface these settings apply -
If
a machine has several network cards, the one booted from may not be eth0, and 
AFAIK the kernel uses the parameter on eth0.

But maybe there's a trick I've missed up to now. Possibly giving the PCI
id
(or even better, PCI location) to the kernel to specify the interface?


Regards,

Phil