[ipxe-devel] iPXE: UUID mis-ordering.

Michael Brown mbrown at fensystems.co.uk
Thu Nov 1 17:31:16 UTC 2012

On Thursday 01 Nov 2012 01:41:13 Matthew Helton wrote:
> I've noticed some misordering of the UUID rendering in iPXE, Observed in
> Asus Gen4 or later Motherboards, and HP's ProLiant Enterprise Servers (G6,
> G7, G8)
> "The true" UUID in BIOS/PXE is:
>  Code: 1F00B3E0-00C6-0800-2C4A-BCAEC5280EAD
> as rendered in the BIOS, PXE UNDI, OS and the iLO information header
> But when iPXE Renders it, we get this:
>  Code: e0b3001f-c600-0008-2c4a-bcaec5280ead
> Is this by design or a vendor BIOS implementation issue?

It sounds like a BIOS issue.  I've verified that iPXE's concept of byte order 
within the UUID matches that of qemu, at least.  Tested by starting qemu with:

  qemu -uuid e5d748af-6f7f-4266-af6f-4c1e710ba56b

and then, within iPXE:

  iPXE> echo ${uuid}

A quick test on physical hardware (AMI BIOS) also shows that iPXE's ${uuid} 
matches the UUID shown by the onboard Realtek PXE ROM on startup.


More information about the ipxe-devel mailing list