[gPXE-devel] what is undi.zrom in gPXE?

[Sean Shoufu Luo]

That's clear now! Thank you, Joshua!


On Thu, Jun 17, 2010 at 11:55 PM, Joshua Oreman <oremanj at rwcr.net> wrote:

> [Please keep the list in the Cc]
>
> On Thu, Jun 17, 2010 at 5:37 AM, Sean Shoufu Luo <luoshoufu at gmail.com>
> wrote:
> > Hi Josh,
> > Thank you for informative explain on UNDI. I still have a question.
> > According to what you said, my understand is UNDI build (undi.zrom)
> contains
> > DHCP/TFTP/... and UNDI driver, and it must work with vendor ROM that
> exposes
> > an UNDI. My question is who provides the UNDI ROM which is loaded to be
> > below 1M memory, undi.zrom or vendor ROM?
>
> So, there are two components here:
>
> - The UNDI interface
> - The UNDI driver
>
> (Sadly, as far as I know these don't have a consistent naming.) The
> UNDI interface is provided by an existing vendor PXE ROM or
> specific-driver Etherboot or gPXE ROM (e.g. rtl8139.zrom). It has a
> special header so it can be found and loaded in such a way that it
> will just expose the UNDI API. The UNDI driver (in undi.zrom and
> friends) looks for a ROM that implements the UNDI interface, loads it,
> and sends and receives DHCP/TFTP/etc packets using the UNDI API that
> it finds. As I said before, *undi.zrom does not make sense and will
> never work*; the UNDI driver should be part of a PXE or CDROM or
> [etc.] build of Etherboot/gPXE with a *different*, driver-specific ROM
> already present in the system.
>
> The main use of UNDI is to allow booting on systems that
> Etherboot/gPXE does not have native driver support for. For it to
> work, you need to still have the vendor PXE ROM in the system.
>
> -- Josh
>
> > Thanks again
> > -Sean-
> > On Thu, Jun 17, 2010 at 10:59 AM, <oremanj at gmail.com> wrote:
> >>
> >> Hi Sean,
> >>
> >> A few things:
> >>
> >> Etherboot is out of date and in maintenance mode only. Please use gPXE
> if
> >> you can, as it has many more features and fewer bugs. :-) If there's a
> >> specific reason you need to use Etherboot over gPXE, let us know; we'd
> like
> >> to fix it.
> >>
> >> UNDI builds of Etherboot and gPXE are meant to be used in tandem with a
> >> preexisting vendor ROM that exposes an UNDI interface. Thus, the
> combination
> >> UNDI + ROM in the same build makes no sense. Etherboot and gPXE expose
> an
> >> UNDI interface no matter what, and in this case Etherboot finds and
> attempts
> >> to load *itself* as the underlying "real" vendor ROM. The results are
> >> predictably awful.
> >>
> >> So what you really want is a ROM with a specific driver included (not
> >> UNDI). Also, consider using gPXE instead of Etherboot.
> >>
> >> Happy hacking :-)
> >>
> >> -- Josh
> >> Sent via BlackBerry by AT&T
> >>
> >> -----Original Message-----
> >> From: Sean Shoufu Luo <luoshoufu at gmail.com>
> >> Date: Thu, 17 Jun 2010 10:48:36
> >> To: <gpxe-devel at etherboot.org>
> >> Subject: [gPXE-devel] what is undi.zrom in gPXE?
> >>
> >> _______________________________________________
> >> gPXE-devel mailing list
> >> gPXE-devel at etherboot.org
> >> http://etherboot.org/mailman/listinfo/gpxe-devel
> >>
> >
> >
> >
> > --
> > Face to sun
> >
>



-- 
Face to sun
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