Some Enterprise-grade HP servers seems to identify with the wrong UUID to iPXE.

gistfile1.pl

#!perl

use strict;
use warnings;

use Test::More;

my $actual_uuid = '1F00B3E0-00C6-0800-2C4A-BCAEC5280EAD';
my $ipxe_uuid   = 'e0b3001f-c600-0008-2c4a-bcaec5280ead';

is( convert_ipxe_uuid($ipxe_uuid), $actual_uuid, "iPXE UUID converted successfully" );

done_testing();

exit;

sub convert_ipxe_uuid {
    my ($ipxe_uuid) = @_;
    my @parts = split /-/, uc $ipxe_uuid;
    $parts[0] = reverse_hex($parts[0]);
    $parts[1] = reverse_hex($parts[1]);
    $parts[2] = reverse_hex($parts[2]);
    return uc join("-", @parts);
}

sub reverse_hex {
    my ($hex_str) = @_;
    return unpack("H*",
        join("",
            reverse
            split("",
                pack("H*", $hex_str)
            )
        )
    );
}

See details here: http://forum.ipxe.org/showthread.php?tid=6685