/etc/cobbler/pxe/gpxe_system_local.template is in cobbler-common 2.4.1-0ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 | #!gpxe
# Boot from local hard disk
iseq ${smbios/manufacturer} HP && exit ||
sanboot --no-describe --drive 0x80
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