Note that multiple operating systems booting on a single machine is still something of a black art. This document does not even attempt to document the various boot managers, which vary by architecture and even by subarchitecture. You should see your boot manager's documentation for more information.
The bootloader on PA-RISC is „palo“. PALO is similar in configuration and usage to LILO, with a few exceptions. First of all, PALO allows you to boot any kernel image on your boot partition. This is because PALO can actually read Linux partitions.