Re: [Etherboot-developers] [RFC] Relocation techniques...

[Michael B. <mb...@fe...>]

On Thu, 11 Jul 2002, Peter Lister wrote:
> > > I agree with what you say, Eric, but this implies complexity on the
> > > dhcp server side to give out images with the right driver. People find
> > > that complicated, so there will be pressure to supply use the initial
> > > firmware driver to be nicely device indepedent.
> > It's not complicated to set up DHCPD to do this; you can find code that
> > will automate it completely in contrib/initrd.
> *I* know that, *you* know that, *Eric* knows that. :)
> <snip>
> WRT safety of design, Eric's absolutely right, though it's worth noting
> that the "opposition" is PXE so the quality threshold is not high. :) I
> think my point is valid; a user who doesn't know much *does* know that
> PXE lets him not worry about which driver to use, so that many people
> will expect drivers to stay resident. Even if one's net booting a full
> Linux kernel, using an EB driver is still useful. If a Linux 'driver'
> for the EB driver using is built in, the kernel can use the EB driver
> for its initial DHCP config; the system can boot and then dynamically
> load a better network driver module later on.

Is it possible to unload and reload the network driver that is connecting
you to your root file system?

> > As is, this will create NBI files for each network module and will
> > provide dhcpd.conf fragments that deal with automatically selecting
> > the correct NBI based on the PCI/ISA IDs that Etherboot sends.  (I
> > need to update this to use the new binary structures.)
> If new LTSP users can automagically get something that just works, then
> that's a significant step forward, but my perception is that most people
> find dhcp voodoo a bit scary, especially if it seems that they have to
> do (as they see it) dangerous things before anything good happens. Yes,
> it's a dhcp server config issue, but we still have to cope with it.

It's pretty automagic.  Steps to get a working terminal server the way
I've done it are:

1. Install the terminal-server package (which will drag in mkinitrd-net
   as well).

2a. If you didn't already have a dhcpd.conf then one will have been
    created for you based on your network configuration.  Just uncomment
    and edit the "range" line and then restart dhcpd.
*or*
2b. If you did already have a dhcpd.conf file then just add the line
    "include /etc/dhcpd.conf.etherboot.include;" somewhere and restart
    dhcpd.

3. It works.  Honestly, that's all you need to do.

NBI images are created automatically and selected automatically via the
dhcpd.conf.etherboot.include file and the
dhcpd.conf.etherboot-pcimap.include file that mkinitrd-net generates
(which dhcpd.conf.etherboot.include includes!).  You really don't need to
know any of the intimate details to get it working.

Michael Brown
http://www.fensystems.co.uk
--
Fen Systems: Linux made easy for schools