[syslinux] alternate tftp server

[Jeffrey Hutzelman]

--On Wednesday, April 02, 2008 03:28:56 PM -0400 Jeffrey Hutzelman 
<jhutz at cmu.edu> wrote:

> --On Wednesday, April 02, 2008 11:50:55 AM -0700 "H. Peter Anvin"
> <hpa at zytor.com> wrote:
>
>> Jacob Alifrangis wrote:
>>> Startrom is actually getting this information from the BINLSVC service
>>> or "Boot Information Negotiation Layer" this service broadcasts a
>>> packet to 255.255.255.255 or to $ipaddress, I'm not sure. What is
>>> definite is that the packet contains the location of the boot loader
>>> wdsnbp.com or an equivalent pxe code file, determined by the
>>> architecture that is detected by startrom.com, this is done by issuing
>>> an assembler instruction that detects 64bit mode.
>>
>> BINL is just butchered DHCP.
>>
>> Supposedly, one can edit the DHCP/BINL packets inside the PXE stack, but
>> it is known not to work for some PXE stacks.  I'm considering writing a
>> COM32 module to do this editing and then chainload a PXE module.
>
> I did this as a comboot module a while back; we use it to support booting
> RIS from pxelinux, as well as booting a new pxelinux with a different
> configuration directory (very convenient for using OS installer images
> as-is).  As the source is only 10K, I've attached it.

I should note that while I haven't tried this with a wide variety of PXE 
stacks, I haven't gotten any complaints, either.  I haven't tested this 
with gPXE, but I do expect it to work there.

-- Jeff