[syslinux] DHCP option 93 for UEFI

[Ady]

Spike, thank you for your reply.
 
> Every UEFI boot client I've ever seen reports 00:07 for VCI & ARCH. Which
> agrees w/ RFC 4578.  I have never tried DHCPv6 however.
 
No, it does not agree with RFC 4578. That's exactly my point.

The DHCPv6 "Architecture Type" option is supposed to be (according to 
the documentation itself) a _compatible_ extension of the 
corresponding DHCP(v4) option, which is itself an extension of the 
corresponding option in the PXE 2.1 specs.

I'll repeat here the relevant lines of both tables:

 RFC 4578     -  DHCPv6
 7 EFI BC     -  7 x64 UEFI
 9 EFI x86-64 -  9 EBC

If you are only seeing "00:07" for UEFI clients (and assuming you are 
referring to the most common in-the-wild hardware/firmware, "UEFI 
X64"), then that's a match for the DHCPv6 table, but not a match for 
the RFC 4578. Or, is (perhaps) all in-the-wild hardware not really 
using UEFI X64 firmware but EFI BC?

Thus, the questions I posted in my previous email.

If in real-life hardware, _all_ UEFI x86_64 systems report "00:07" 
and _all_ "UEFI BC" firmware reports "00:09", then the DHCP 
configuration file seems to be clear for every case. But if this is 
not the case, there might be problems to boot some clients when using 
the "Architecture Type" option in the dhcp configuration file.

In addition to the potential "real-life" problem, there is the 
(seemingly) "paper-only" problem. Is there a typo in either one of 
these documents? Should some potential Errata be evaluated?

Considering that:
_ the original EFI specs; and,
_ the PDF document "IPv6 Remote Boot Requirements From UEFI Forum", 
IETF 72, 2008; and,
_ the "dhcpv6-parameters" document; and,
_ the RFC 4578; and,
_ the PXE 2.1 specs,

are *all* written by (some person inside) Intel and supported (or 
endorsed or some similar term) by The UEFI Group, then the 
conflicting information "should" have some kind of explanation (and, 
maybe, a solution).

Considering that some Intel people and some UEFI-related guys are 
subscribed to this Syslinux Mailing List (and they might, perhaps, on 
some occasion, also read some email in it), I hope this matter can be 
eventually clarified and the conflicting information be resolved.

I would welcome any input on this matter.

TIA,
Ady.