Program Organization
Tbe fM/370 procedures for generating and
updating VM/370 consist of three EXEC procedures (VMFASM, VMFMAC, and GENERATE)
and three modules (VMFDATE, DMSUPD, and VMFLOAD). The Assembler language update procedure
consists of the VMFASM EXEC procedure and two modules (VMFDATE and DMSUPD). The VMFASM EXEC procedure sets up for the
assembly by calling DMSUPD to create the
update control file. There is an entry in
the VMCNTRL file for each update control
and auxiliary update file. The VMCNTRL identifies the updates applied to the
original assembler program and the date and
time they were applied.
The Assembler language update procedure
calls the VMFDATE program. The MACLIBs needed are then included in the VMCNTRL file.
The nucleus loader procedure consists of
a program (VMFLOAD) and an EXEC procedure.
Although the DMSUPD update program is not
used, the centrol file that it creates may te used. The LOADER EXEC procedure lists the nucleus modules in the order they are to be loaded. The list includes the
filename of each module and may opticnally
include the update level. If the update level is not specified, the control file
created 1:y DMSUPD is used te locate the
highest level update available, and that
level of the module is leaded. When nucleus modules are updated and
loaded, it is often necessary to create a new macro library. ThE level of macro lil:rary needed for each updated module is recorded in the VMCNTRL file created by the VMFrATE module. The VMFMAC EXEC procedure
creates a new macro library.
The GENERATE EXEC prccedure reassembles
the DMKRIO, DMKSYS, Dl8FCB, and DMKSNT modules by using the EXEC procedure. It loads the CP, CMS, or RSCS.nucleus using
the VMFLOAD program. In addition, it can
build a new VM/370 directory, punch the
standalone service programs, or make a
self-relocating copy of the service
programs, or load the IPCS modules from
tape onto the IPCS A-disk.
Chapter 7. Procedures for Generating and updating VM/370 149

Directory Four label directories are provided.
Figure 7-3 is the label directory for the Assembler update function, including labels from: • The VftFASM EXEC procedure. • The DMSUPD update program. • The VMFDATE control file program. Figure 7-4 is the label directory for
the nucleus load program, VBFLOAD. Figure 7-5 is the label directory for
the VMFMAC EXEC procedure, which creates
and updates the macro library.
Figure 7-6 is the label directory for
the GENERATE EXEC procedure, which creates
new service program decks, builds a new CP, eMS, or RSCS nucleus, or loads the IPCS .odules fro. tape onto tbe IPCS A-disk. 150 IBM VM/370 Service Routines program Logic