344 IBM VM/370 Planning and System Generation Guide

Updating CP Building a New CP Nucleus If you are going to use the MAINT userid to load and test a new CP nucleus, you should be sure that MAINT's virtual machine has: • A minimum 512K of virtual storage. The loader requires 512K to
execute. In general, MAINT's virtual machine should have as much
virtual storage as the real machine storage size. • The ECMODE option specified in the VM/370 directory (or has used the CP SET ECMODE ON command) • ECMODE is required for testing the CP system in your virtual machine. • write access to the CP system residence volume, or a minidisk that is
a replica of the system residence volume. The minidisk must be
defined in your virtual machine at the same address as the real
address of the system residence volume. The minidisk must have been
formatted with the CP Format/Allocate program, such that it resembles
the CP system residence; nonexistent cylinders beyond the extent of
the minidisk must be allocated as permanent space (PERM). When you prepare to load a new CP nucleus, you should be sure that
you have the disks containing object modules accessed in the proper
order to ensure that the correct files are punched. Then you issue the
following series of commands:
close punch
purge punch all
close reader
purge reader all
spool punch *
vmfload yourload yourown
where YOURLOAD is the loadlist EXEC file and YOUROWN is the control
file. When the VMFLCAD program completes, you receive the messages: SYSTEM LOAD DECK COMPLETE PUN FILE 0821 TO MAINT COpy 01 NOHOLD At this point the standalone loader (DMKLDOOE LOADER) is in your card
reader, followed by all of the text decks necessary to construct a CP nucleus. There are several ways to handle this reader file.
First, you can use the CMS MOVEFILE command to place the entire file
on tape, thus creating a CP nucleus load tape. Later you can IPL the
tape drive on the real machine when you want to update the CP system.
Remember, however, that the loader requires 512K of storage.
The second way to handle the CP nucleus reader file is to IPL the
loader from the tape. If you have access to the real system residence
device in your virtual machine, the nucleus is written on the real
system residence volume. If you have a minidisk defined at a virtual
address corresponding to the real address of the CP system residence
disk, the nucleus is written on that A third way is to IPL the nucleus directly from the card reader; this
method is shown in the example that follows. However, it does not
provide you a backup copy that you can IPL. Part 5. Updating VM/370 3q5