Recommended Procedures for Updating VM/370 The procedures that you can use to apply local updates are similar for CP, CMS, RSCS, and IPCS. The examples in the following pages use CP modules and control files to illustrate the use of: • The VMFASM EXEC Procedure • The VMFMAC EXEC Procedure • The VMFLOAD Program You should keep in mind that the procedures for updating source files
and macro libraries are the same for all VM/370 components, and that the
procedure for punching a new eMS or RSCS nucleus is basically the same
as the procedure for punching a CP nucleus.
For specific details and special considerations for loading and
testing a new CP, CMS, or RSCS nucleus, or for generating new IPCS modules, see: • "Building a New CP Nucleus" • "Updating CMS" • "Updating RSCS" • "Updating IPCS Modules"
The minidisk areas used in the examples in all of these discussions
use the MAINT virtual machine described under "A Virtual Machine For
Updating VM/370" and illustrated in Figure 35. Note tha t the virtual
machine configuration consists of the MAINT entry in the IBM-supplied VM/370 directory, with the addition of MDISK statements for virtual
disks (193, 294, 393, 394, and 390). Figure 35 shows the virtual disks
described by the resultant MAINT entry. This virtual machine
configuration should provide you with all the areas you need to update
and test VM/370. '/1\1I/370In+enri+y ;; ;v./ • • ••• • •• In order to preserve the integrity of VM/370 source and text files, you
should keep updates and PTFs on a separate minidisk (not on the same
disk as the original source and text files). This minidisk (usually MAl NT's 294) should contain the required IBM PTF updates from the latest
system PUT, updates that you make (such as expanding the accounting
routines or adding a command to CP), and the resultant text files
containing the updates. You also need access to the current CP text files and macro
libraries. This is MAINT's 194. This is the disk used by VMSERV when
it loads replacement text files from the System PUT. The assembler language source files are on the 394 minidisk. You should not change these files, unless directed to do so by the Memo to Users. When you use the CMS UPDATE command and the VMFASM and/or VMFMAC EXEC procedures with the suggested virtual machine configuration shown
in Figure 35 and the access s€arch order shown in the following
examples, modified files are written onto your A-disk. Also, you
should not change the IBM-supplied auxiliary files nor the PTF (XnnnnDMK) files as these are controlled by the PUT procedure. Part 5. Updating VM/370 333

Recommended Procedures
If you want to update a VM/370 component, you should create your own
control file. This file should contain entries for your own updates as
well as for the IBM-supplied updates. Control File Preparation
Control files are used by the CMS UPDATE command. Both the VMFMAC and VMFASM update procedures invoke UPDATE with the CTL option to modify
source files. For VMFMAC and VMFASM, the control file must have a
filetype of CNTRL. In addition, the VMFLOAD program also uses a control
file: this is usually the same control file used by the VMFASM EXEC. For an understanding of how the update procedures work, you should
have a thorough understanding of the elements in a control file.
Control files are described extensively in the and the VM/J70 and The following
discussion summarizes how VMFMAC, VMFASM, and VMFLOAD use the control l*THIS IS A SAMPLE CNTRL FILE FOR LOCAL CP UPDATES TEXT MACS2 LOCALIB DMKMAC CMSLIB OSMACRO UP3 UPDTFIX 1. PTF5 FIXTEST LCL AUXLCL6 TEXT AUXRn0
7 IThis is a comment record. 2VMFASM uses the library list from the MACS record to issue a GLOBAL command before assembling the updated source file. The libraries are
searched in the order specified. DMKAMAC should precede DMKMAC if AP support is required. 3VMFASM and VMFLOAD use the update level identifier to identify the text
deck. VMFASM uses the update level identifier of the most recent
update that was found and applied to name the text deck produced by the
assembly. VMFLOAD uses update level identifiers to locate text decks
when punching a new CP, CMS, or RSCS nucleus.
The update level identifier on the MACS record is used by VMFASM to
name an assembled update text deck when no update files are found; it
is also used by VMFLOAD when it fails to locate a text file based on
update level identifiers associated with update files or auxiliary
control files . • The characters UPDT identify the filetype of a single update file, UPDTFIX 1 in this example. (The characters "UPDT" maybe omi tted.)
5The characters PTF in the update level identifier field identify this
file as a PTF file. FIXTEST is the filetype of the update file.
6The characters AUX identify an auxiliary control file that lists
additional updates to be applied, local modifications in this example. 7AUXRnO is the VM/370 auxiliary control file, listing updates
distributed by IBM. This file is listed at the bottom of the control
file so that these updates are applied first.
334 IBM VM/370 Planning and System Generation Guide