Introducing an element—the function SYSMOD

One way you can modify your system is to introduce new elements into that system. To accomplish this with SMP/E, you can install a function SYSMOD. The function SYSMOD introduces a new product, a new version or release of a product, or updated functions for an existing product into the system. All other types of SYSMODs are dependent upon the function SYSMOD, because they are all modifications of the elements originally introduced by the function SYSMOD.

When we refer to installing a function SYSMOD, we are referring to the placing of all the product's elements in the system data sets, or libraries. Examples of these libraries are SYS1.LPALIB, SYS1.MIGLIB, and SYS1.SVCLIB. Figure 1 depicts the process of creating executable code in the production system libraries.

Figure 1. Introducing an element

Executable code is created in the production system libraries.

In this figure, the installation of a function SYSMOD link-edits object modules MOD1, MOD2, MOD3, and MOD4 to create load module LMOD2. The executable code created in load module LMOD2 is installed in the system libraries through the installation of the function SYSMOD.

There are two types of function SYSMODs:

A base function SYSMOD adds or replaces an entire system function. Examples of base functions are SMP/E and JES2.
A dependent function SYSMOD provides an addition to an existing system function. It is called dependent because its installation depends upon a base function already being installed. Examples of dependent functions are the language features for SMP/E.

Both base function SYSMODs and dependent function SYSMODs are used to introduce new elements into the system.

Here's an example of a simple function SYSMOD that introduces four elements:

   ++FUNCTION(FUN0001)         /* SYSMOD type and identifier.   */.
   ++VER(Z038)                 /* For MVS SREL                  */.
   ++MOD(MOD1)  RELFILE(1)     /* Introduce this module         */
               DISTLIB(AOSFB)  /* in this distribution library. */.
   ++MOD(MOD2)  RELFILE(1)     /* Introduce this module         */
               DISTLIB(AOSFB)  /* in this distribution library. */.
   ++MOD(MOD3)  RELFILE(1)     /* Introduce this module         */
               DISTLIB(AOSFB)  /* in this distribution library. */.
   ++MOD(MOD4)  RELFILE(1)     /* Introduce this module         */
               DISTLIB(AOSFB)  /* in this distribution library. */.