've been trying to sort out our kickstart infrastructure and hit one
box I just could get to co-operate without external intervention - it
has three NICs, the onboard ones start at eth1 (which is the one I
need it to use), but eth2 also has a link (which is why ksdevice=link
didn't help).

So instead I implemented `ksdevice=bootif' which when used with
`IPAPPEND 2' in your pxelinux.cfg pulls the BOOTIF variable off the
command line and uses the mac PXE booted the machine from as the
interface for ksdevice (which exactly matches the behaviour I want).

Awesome, thanks for the patch (especially updating the docs :)

Applied in CVS