EFI boot issue on ESXi-5.5.0-1331820-standard

[robertbarnhardt]

Hi.

Hoping someone can confirm or deny an issue with EFI boot on ESXi-5.5.0-1331820-standard when using the DHCP option bootfile-name (as opposed to the BOOTP file field).

What I'm seeing is that the DHCP bootfile-name option isn't interpreted correctly by the EFI ROM: the TFTP request comes back with a broken filename, which actually contains not just the filename but the binary contents of the remainder of the DHCP packet (or at least the DHCP options area).

Example -- if the last two options in the DHCP offer on the wire are...

bootfile-name "syslinux.efi"  # <code:67> <length:12> syslinux.efi

end # <code:255>

...the TFTP request will come back with the filename "syslinux.efi\377" (with the DHCP end code of 255 [= octal 377, here] appended) instead of "syslinux.efi".

It appears this can be worked around by either (1) using the BOOTP file field instead of the DHCP option, or (2) appending an ASCII NUL to the bootfile-name option in the dhcpd configuration (i.e. bootfile-name "syslinux.efi\000").

If this is a known issue, has it been resolved in a later ESXi 5.5 update or ESXi 6.0?

Thanks!

[dariusd · Accepted solution]

Hi Robert, and welcome to the VMware Communities!

We use the open-source EDK2 project as the basis for our EFI implementation.  It looks like we'll need to grab the following bugfix from EDK2 in order for bootfile-name to work correctly: EDK II / Code / Commit [r15099]

I doubt we will have acquired that bugfix in ESXi 6.0, so I at this stage I don't think updating will fix it, unfortunately.  I'll report back if investigation proves otherwise.

I'll file a bug report to see about having it fixed.  Thanks for the detailed troubleshooting you've done, and the great problem report!

Cheers,

--

Darius

[robertbarnhardt]

Darius,

Thanks for the excellent, informative, quick response; very much appreciated!

Take care,

- Robert.