Re: [Etherboot-developers] NBP Help

[Peter L. <P.L...@sy...>]

>      I am working on PXE. I would like to know how NBP interacts with
> PXE? do they use PXE stack Or they are OS loaders and so they install OS
> first and use the OS stack?

Read the PXE spec.

NBPs can use as much PXE as they need to (and unload what they don't
need). The UNDI network driver is available to NBP. So is DHCP/TFTP but
it's normally broken; use the etherboot code.

Look at Etherboot's PXELOADER code in loader.S to see a minimal NBP. It
just unloads the whole of PXE and then proceeds as if loaded from rom,
using it's own driver. There is a placeholder compile flag to leave UNDI
loaded for anyone interested in getting Etherboot to use it. Compare
with pxelinux, which uses UNDI, DHCP and TFTP.

I hope it's obvious that Etherboot must use either UNDI or a native
driver, or there's no way to load the OS. :)

Out of interest what are you doing with PXE? If all you need to do is
boot Linux, Etherboot or pxelinux will do this now. Writing a new NBP
just for fun seems pointless. Unless you have an odd idea of "fun".

Adding UNDI support as an Etherboot driver would be a good NBP project
and could form the basis of a useful open source NBP toolkit. It would
be useful to quite a few people because it would make Etherboot via PXE
easier to set up for sites which have many hardware types.

You could also improve Etherboot's PXE support (i.e. so that Etherboot
can provide PXE to other NBPs), maybe merging the existing the NILO code
so that Etherboot can run any NBP. The standard of the Intel PXE code
library (used in most vendor's NIC firmware) is - er - low. Look at
HPA's pxelinux pages or read the syslinux list to see just how low. Even
devoted PXE users would like better open source PXE firmware; Etherboot
(and it's driver library) is the obvious platform and has had skeleton
PXE support added already (which, I note, Eric B just migrated to its
very own pxe.c). This could be chainable (a "menu module"?) from a
"vanilla Etherboot" in turn loading a "real" NBP like NTLOADER. Or even
be statically linked with an existing binary NBP...

mknbi-pxe closedOS.pxe closedOS.nbi

...to turn it into something which can be loaded directly by Etherboot!

>    Can anybody tell me links those will give me more deatiled
> information on NBPs

Intel changed the URL, but kept no placeholder; even their own URLs have
not been updated, so you can be forgiven for not finding it...

http://www.intel.com/labs/manage/wfm/wfmspecs.htm