[syslinux] syslinux.efi and vendor-class-identifier

[James Pearson]

Gene Cumm wrote:
> 
> On Fri, Oct 4, 2019 at 7:47 AM James Pearson via Syslinux
> <syslinux at syslinux.org> wrote:
>>
>> Ady Ady via Syslinux wrote:
>>>
>>>> We're using a CentOS 6 server running its native (ISC) dhcpd (v4.1.1)
>>>> and tftpd (v 0.49). I've installed syslinux.efi and ldlinux.e64 from the
>>>> syslinux-6.04-pre2 distro alongside the existing pxelinux.0
>>>
>>>
>>> Please avoid the official binaries from Syslinux 6.04-pre2 and
>>> 6.04-pre3. Additionally, the current git master head is not useful for
>>> troubleshooting.
>>>
>>> Whether the specific version actually has any kind of influence on
>>> these particular tests, I don't know (but, at any rate I would avoid
>>> the aforementioned versions anyway).
>>>
>>> Please try either official binaries from 6.04-pre1, or from current
>>> Debian Testing.
>>>
>>> Please avoid mixing Syslinux-related files from different
>>> versions/builds (within the same platform).
>>
>> I tried with 6.04-pre1 - it made no difference, the same issue as with
>> 6.04-pre2
>>
>> I had a look through the syslinux code, but I couldn't work out if
>> syslinux.efi is responsible for the 2nd DHCP Discover I see via tcpdump
>> (I can't pretend to understand the code, so I might not be looking in
>> the right place)
>>
>> i.e. is it syslinux.efi that tries a DHCP transaction between
>> downloading syslinux.efi and downloading ldlinux.e64 - or is this done
>> by the host's EFI PXE firmware ?
> 
> Since I don't recall ever seeing this kind of behavior, it makes me
> think it's system-specific while SYSLINUX initializes the interfaces.
> I assume you get no output on the screen?

The hardware I'm using is a Dell 3930 rack mount workstation - but as 
this is the first time I've tried EFI PXE booting, I'm not sure what to 
expect ...

I get on the screen:

  Getting cached packet
  MY IP is 10.64.79.186
  core_udp_sendto: stalling on configure with no mapping
  core_udp_sendto: aborting on no mapping
  disable UseDefaultAddress
  core_udp_sendto: udp->Configure() unsuccessful (20)

I believe the above errors are from the TFTP client in syslinux.efi 
complaining - which is probably because the 2nd DHCP transaction fails ?

However, I have just tested the exact same boot procedure using a Dell 
laptop (Latitude 7480) - and it all worked without a problem - that is, 
syslinux.efi and ldlinux.e64 were downloaded without a problem - and 
from a tcpdump, there was *no* DHCP transaction between downloading 
syslinux.efi and ldlinux.e64

So I'm puzzled as to why it doesn't work on the Dell 3930 - may be a 
firmware bug/feature (it is running the latest firmware) ?

Thanks

James Pearson