On Jan 21, 2006, at 5:10 PM, Richard Bos wrote:
would you be so kind to get me updated about booting from the net
via pxe,
etherboot and the like.
Hi there. Perhaps I can be of help. I created and maintain rom-o-
matic.net, and am Project Leader for the Etherboot team.
PXE is a method for booting and managing computer via a network
connection. Etherboot implements PXE as do various pieces of
software. Etherboot didn't used to implement the PXE method of
booting. Support for PXE was added in the last couple of years.
I understand how it works, but I miss the fine
details to really implement it. BTW I started to become interested
in pxe
after reading an email exchange between Jim McQuillan and Simon
Langley about
getting notebooks/laptops connected with a wireless pocket access
point
device (wireless bridge) (september last year). From the wiki I
understand
that the notebook should be booted using pxe.... here my adventure
(questions) starts ;)
Good questions. I'm glad you're wondering, and glad you're trying to
find out.
Sofar I understand that the etherboot images from rom-o-matic can
be used for
this purpose.
They can be used to boot computers over the network using both PXE
method and what we'll call the NBI method of network booting.
Etherboot and PXE methods both use DHCP and TFTP. Etherboot supports
some additional protocols, and when using Etherboot's older method of
booting, the image to be booted is prepared (wrapped) using a tool
called mknbi (make-network-boot-image).
In my case I have succesfully created floppy boot images. Is
it now possible (in the client system) to swap these floppy
bootimages for
networkcard pxe images (by programming an eprom image from rom-o-
matic) and
have the same machine still booted via the network? I mean is no
there no
bios option that needs to be changed (for example: change boot
order. Make
lan the first thing to try instead of the floppy disk drive). As
far as I
remember I have not seen a 'boot from the lan' option in the bioses
that I
have looked at. Is it like this, that when a pxe image is present
in a
network card, it automatically boots the machine?
I did not find this explained on this page:
http://wiki.ltsp.org/twiki/bin/view/Ltsp/PXE hence I my question.
BIOSes have evolved, and have different ways of expressing network
booting capability. If you have a reasonably recent Intel
motherboard, for instance, with a Phoenix BIOS, and you put a NIC
card in with a PXE boot ROM on it, when you go to the BOOT menu, you
can actually see the boot ROM as a boot option along with the floppy
and hard drive, and you can set its order. This is part of the BIOS
specification, and if your boot ROM is "PNP Conformant" (and your
BIOS is), you can set the boot priority of things like Adaptec SCSI
cards, and Ethernet Cards, and your BIOS will respect it.
Not all BIOSes correctly implement PNP, but quite a few do. A BIOS
update in many cases will help. If the BIOS copyright date is in the
early 1990s, you may have some difficulty, and in that case,
Etherboot will likely just run.
For the moment I just assume that pxe boots the system when it is
present.
This is for my next question. In case a noteboot does not support
pxe on its
own ethernet card (pcmcia card), would the following card make any
notebook
pxe enabled:
http://www.argontechnology.com/product.aspx/cid1/103/pid/304 ?
It sounds strange to me, that when a notebook is not aware of pxe
on its one
because it was never designed for it, that it would now
automatically work
when the above mentioned card is plugged in....
Product Description
Argon's EP-4103DL-PXE Cardbus Fast Ethernet PC Card with PXE
10/100 Fast Ethernet Dongle-less PCMCIA
Complies with IEEE 802.3 10BaseT and 802.3u 100BaseTX Standards
Supports 10/100M Auto-Negotiation 32bit High Performance 100Mbps
Networking
PXE Support included with Argon's PXE on Disk: works with Argon
Client Management
Services (CMS) PXE Server or Microsoft Remote Installation
Services (RIS).
Hmm, I believe that you'll need to boot from their floppy to get PXE
to work.
The technical reason is that when most notebook boot, unless their
Ethernet ports are on the motherboard, they have to initialize a PCI
to PCMCIA bridge chip.
The question is, where is the code to do this? Well, it kind of has
to be done by the BIOS, which would then have to know how to control
whatever PCMCIA Ethernet card you happen to have plugged into your
PCMCIA slot.
There's the rub. Unless your laptop BIOS specifically knows what
bridge chip is being used, and what PCMCIA card is being used, most
laptops without Ethernet wait for a kernel or other boot code (like
Argon's PXE on Disk (kind of like an Etherboot floppy)), to do it.
Etherboot, unfortunately doesn't yet know how to deal with PCMCIA
buses. It's one of the things we hope to add, but so far, we do PCI
and ISA buses mainly, which takes care of the majority of cases.
We'd like to do PCMCIA and USB, and I'm sure we'll get there in time.
Someone will decide they want it, and do it or fund it, just like PXE
support.
I'll highly appreciate any explanation on pxe. The wiki pages are
good, but
unfortenately they just missed the 2 points mentioned above.
I hope this is helpful. I think my answers are correct. I hope and
expect that someone will correct me if I am mistaken.
Another question I have (just out of curiousty); what ethercards
support pxe
out the box nowadays all? Or should they all get an eprom to
enable pxe?
Same question for notebooks, which notebooks support pxe nowadays,
is that
all or for example only the IBM thinkpad (that's the answer from
google) ;)
For an Ethernet card to support PXE out of the box, it needs a flash
EEPROM. This raises the cost, but not so much as in the old days. I
think I noticed an RTL8169 (Gigabit Card) that has PXE on it for not
too much more than $20 the other day.
Now, if you're a bargain hunter, you can find old Intel EEPRO100s and
3COM 3C905CTXM cards, which have PXE in flash memory, and will
network boot by loading PXELINUX.0 from the SYSLINUX/PXELINUX/
ISOLINUX package.
Well, hopefully some of that will make sense, and help you on your
way. If you need more information, please post to the list. We're
here to help.
TIA
You're welcome.
Richard Bos
Without a home the journey is endless
Marty
--
Try: http://rom-o-matic.net/ to make Etherboot images instantly.
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