Mailing List Archive: PXE stack on bootrom [Was: Re: pxelinux fron Floppy disk?]

PXE stack on bootrom [Was: Re: pxelinux fron Floppy disk?]

Apr 3, 2002, 4:27 PM

Post #1 of 4 (1121 views)

On Wed, Apr 03, 2002 at 03:59:49PM -0800, H. Peter Anvin wrote:
> PXELINUX requires PXE. It can't function without it. I would really
> love to see an open source *PXE* stack that could be burned into ROM or
> booted from a floppy, and although there has been some work on it
> (http://www.nilo.org/) I don't think it's practically usable.

If I understood well, there is a spec of the protocol. And it seems logical
that there are specs of how to build such an image, because it's already done
(correct me if I'm mistaking). Is there some special machine code the roms
have to be in, or is it just plain old i386 ? It sounds like a nice project
to freshen my (reduced-to-zero) ASM knowledge, and if it's not i386 then
still it sounds pretty nice.

Do you have more info about that ?

Another thing: _if_ I will do this (it's definitly not sure I will) I'd like
to have some hardware sponsored for testing (not really big stuff, just a nice
flasheable nic or so). I saw some big(ger) names passing this list, so I'm
sure something can be arranged or so. *this is just an early request to see
if there's animo for this. it's not nessecary, but it would be nice*

grtz, Tijn

--
2:19AM up 35 days, 14:35, 10 users, load averages: 0.29, 0.11, 0.09

PXE stack on bootrom [Was: Re: pxelinux fron Floppy disk?] [ In reply to ]

hpa at zytor

Apr 3, 2002, 4:51 PM

Post #2 of 4 (1066 views)

Permalink

Martijn Bakker wrote:
>
> If I understood well, there is a spec of the protocol. And it seems logical
> that there are specs of how to build such an image, because it's already done
> (correct me if I'm mistaking). Is there some special machine code the roms
> have to be in, or is it just plain old i386 ? It sounds like a nice project
> to freshen my (reduced-to-zero) ASM knowledge, and if it's not i386 then
> still it sounds pretty nice.
>
> Do you have more info about that ?
>
> Another thing: _if_ I will do this (it's definitly not sure I will) I'd like
> to have some hardware sponsored for testing (not really big stuff, just a nice
> flasheable nic or so). I saw some big(ger) names passing this list, so I'm
> sure something can be arranged or so. *this is just an early request to see
> if there's animo for this. it's not nessecary, but it would be nice*
>

There is a spec, and my understanding is that it is based at least in
part on the NDIS 2.0 specification, so it *MIGHT* be possible to create
a generic kit that uses an NDIS 2 driver. Otherwise using a modified
Etherboot or Netboot would be a sensible option.

The ROMs are just i386 machine code, typically, with a special (not
particularly complicated) header. A lot of them are written with a
compressed header in order to get more code. The PXE stack is
invariably loaded into the high end of conventional (lower 640K) memory,
although it frequently is at least partially written in protected-mode
code (there is a 32-bit PM entry point, which you must be able to handle.)

-hpa

Re: PXE stack on bootrom [ In reply to ]

martijn-syslinux at insecure

Apr 3, 2002, 5:02 PM

Post #3 of 4 (1080 views)

Permalink

On Wed, Apr 03, 2002 at 04:51:44PM -0800, H. Peter Anvin wrote:
> There is a spec, and my understanding is that it is based at least in
> part on the NDIS 2.0 specification, so it *MIGHT* be possible to create
> a generic kit that uses an NDIS 2 driver. Otherwise using a modified
> Etherboot or Netboot would be a sensible option.

I was already thinking about the last option. It's cheaper. The code can give
implementation ideas, at least, so I'm going to look at it anyway.

> The ROMs are just i386 machine code, typically, with a special (not
> particularly complicated) header. A lot of them are written with a
> compressed header in order to get more code. The PXE stack is
> invariably loaded into the high end of conventional (lower 640K) memory,
> although it frequently is at least partially written in protected-mode
> code (there is a 32-bit PM entry point, which you must be able to handle.)

sounds like a doable thing. I'll try and get into it as soon as it's weekend.

btw, a really stupid question, that probably has the answer under the first
result in google, but I have this 3c905c, and it has 2 modes for booting from
the net: "dhcp/bootp + tftp" and "PXE". as it seems, they do the same. Am I
crazy ?

grtz, Tijn

--
2:54AM up 35 days, 15:10, 9 users, load averages: 0.00, 0.04, 0.06

Re: PXE stack on bootrom [ In reply to ]

hpa at zytor

Apr 3, 2002, 5:09 PM

Post #4 of 4 (1072 views)

Permalink

Martijn Bakker wrote:
>
> btw, a really stupid question, that probably has the answer under the first
> result in google, but I have this 3c905c, and it has 2 modes for booting from
> the net: "dhcp/bootp + tftp" and "PXE". as it seems, they do the same. Am I
> crazy ?
>

I bet the first mode doesn't attempt to query a PXE server in addition
to the DHCP server. This is probably a Good Thing[TM]. :)

-hpa