Multiple Configuration Boot Support
The "multiboot" patch adds the ability to IPL different configurations from the same device using the LOADPARM parameter on VMs IPL command or the "Load Parameter" field on the Hardware Management Console.
It is especially useful when IPLing zLinux in an LPAR. You may setup several configs in /etc/zipl.conf, like a known good one, a test one, and one that IPLs into single user mode. Then, if something untoward happens while testing, you have alternatives to get zLinux back up.
The patch applies to s390-tools-1.1.6.