[syslinux] Chainloading pxe boot loaders and dhcp root-path option

[Gene Cumm]

On Thu, May 19, 2011 at 06:26,  <Kjetil.Mikkelborg at kongsberg.com> wrote:
> Any progress in this rewrite?
> I have been watching this list since you announced your work in hope that you might succeed one day :)

Not really yet.  It's still on my mind though.

> -----Original Message-----
> From: syslinux-bounces at zytor.com [mailto:syslinux-bounces at zytor.com] On Behalf Of Gene Cumm
> Sent: 17. mai 2011 00:09
> To: For discussion of Syslinux and tftp-hpa
> Subject: Re: [syslinux] Chainloading pxe boot loaders and dhcp root-path option
>
> On Mon, May 16, 2011 at 16:34, Jeffrey Hutzelman <jhutz at cmu.edu> wrote:
>> On Sat, 2011-05-14 at 23:39 -0700, H. Peter Anvin wrote:
>>> On 05/14/2011 09:14 PM, Matt Fioravante wrote:
>>> > Is there anyway to set dynamically set dhcp options when chain
>>> > loading another pxe boot loader?
>>> >
>>> > I'm setting up a pxelinux network install server and one operating
>>> > system I want to support is freebsd.
>>> >
>>> > Freebsd has its own pxe loader called pxeboot that you can use. You
>>> > just have to boot it from tftp and set the root-path dhcp option
>>> > (option 17) to the location of your nfs server with the kernel and network filesystem.
>>> >
>>> > I want to support multiple versions of freebsd (i386 and amd64)
>>> > along with Linux distros and others. The are hackish ways to
>>> > accomplish this using memdisk, but thats not a great idea if you
>>> > want to have a 280MB live cd image. The most elegant way I can see
>>> > to do this is to chain load freebsd's pxeboot loader from pxelinux.
>>> > The problem is when you do this, the dhcp root-path option is not set and defaults to /.
>>> >
>>> > I need to be able to dynamically change this dhcp option before
>>> > chain loading into the next pxe boot loader. Essentiallly, I'd like
>>> > to be able to do something like this:
>>> >
>>> > LABEL fbsd32
>>> > pxe pxeboot.0 dhcp-root-path=/nfsserv/freebsd/i386/root
>>> >
>>> > LABEL fbsd64
>>> > pxe pxeboot.0 dhcp-root-path=/nfsserv/freebsd/amd64/root
>>> >
>>> > Is this at all possible with pxelinux?
>>> >
>>>
>>> This is what pxechain.com does.  This assumes that pxeboot.0 gets the
>>> DHCP options from memory and not by doing its own DHCP request.
>>
>>
>> I don't think so.  pxechain.com overwrites the next-server and
>> filename fields in the bootp response, but the OP is asking about a
>> DHCP option, "root path", which is something different entirely.
>> Currently pxechain.com doesn't support modifying DHCP options.  I
>> suppose that could be added, but it's probably nontrivial.
>
> pxechain.com asks the PXE stack to reconfigure those.
>
> I did start to get into writing a pxechain.c32 that could do full processing.
>
> --
> -Gene
>
> _______________________________________________
> Syslinux mailing list
> Submissions to Syslinux at zytor.com
> Unsubscribe or set options at:
> http://www.zytor.com/mailman/listinfo/syslinux
> Please do not send private replies to mailing list traffic.
>
>
> ________________________________
>
> CONFIDENTIALITY
> This e-mail and any attachment contain KONGSBERG information which may be proprietary, confidential or subject to export regulations, and is only meant for the intended recipient(s). Any disclosure, copying, distribution or use is prohibited, if not otherwise explicitly agreed with KONGSBERG. If received in error, please delete it immediately from your system and notify the sender properly.
>
> _______________________________________________
> Syslinux mailing list
> Submissions to Syslinux at zytor.com
> Unsubscribe or set options at:
> http://www.zytor.com/mailman/listinfo/syslinux
> Please do not send private replies to mailing list traffic.
>
>



-- 
-Gene

"No one ever says, 'I can't read that ASCII(plain text) e-mail you sent me.'"