Discontiguous Saved Segments • Assign a name to segment and specify where it is to be stored on
disk. To do this, define an entry in the system name table(DMKSNTBL) with the NAMESYS macro.. See "Coding the NAMESYS Macro" in "Part 2. Defining Your VM/370 System." Or you can use the entries in
theDMKSNT module supplied with the starter system. • Load and save the segment, using the appropriate EXEC procedure (CMSXGEN, DOSGEN, or VSAMGEN). • Be sure that the proper linkage for attaching and detaching
di-scontiguous saved segments is in the operatings-ystemthat needs
the segment.CMS contains the linkage necessary to attach and detach
the discontiguous saved segments it supports.
Usually, the direct access storage space is allocated and the system
name table entries are created during system generation.You allocate DASD space as permanent (PERM) by executing the Format/Allocate program.
This program is executed during system generation, but it is a
standalone program that can be executed at any time. During system
generation, you designate the Cp-owned volumes by coding theSISOWN macro of the DMKSYS file. The system name table (DMKSNT) is also
created during system generation. If, at some time after system
generation, youwish to change the DMKSYS or DMKSNT files, you can do a
partial system generation and reassemble those files using the GENERATEEXEC procedure. GENERATE is described in "Part 5. Updating VM/370." You can load and save a discontiguous saved segment any time after
system generation.£Q1!§ideratiQ1!§.!Q!: Using ,ihe and By the time you complete the VM/370 system generation procedure, the CMS editor, EXEC, and OS simulation load modules exist on the CMS S-disk. Also, if you have followed VK/370 recommendations, you have created a
discontiguous saved segment, calledCMSSEG, that contains the CMS editor, EXEC, and OS simulation routines (you save in Step 24). During virtual machine execution, CMS handles a call to the editor or EXEC processor as follows: • CMS first searches for editor or EXEC load modules on all accessed CMS disks, except the S-disk. If you wanted to test changes made to the editor or EXEC processor, you could place the load modules on a disk other than the S-disk (that is available only to your virtual machine) and test
those changes.• CMS next attempts to attach the shared segment. If you have not
reset the name of the shared segment by issuing aSET SYSNAME command, CMS attempts to attach the CMSSEG segment. If you wish to
use an alternate segment, indicate the alternate segment on aSET SYSNAME command and issue that command before the segment is
attached. If you do not wantCMS to attach a shared segment when
editor,EXEC, or OS simulation routines are needed; issue a SET SISNAME command specifying as the segment name any name that does not
correspond to a named saved segment.• Last, CMS attempts to load the appropriate modules from the CMS S-disk. Part 1. Planning for System Generation 83
disk. To do this, define an entry in the system name table
the
di-scontiguous saved segments is in the operating
the segment.
the discontiguous saved segments it supports.
Usually, the direct access storage space is allocated and the system
name table entries are created during system generation.
This program is executed during system generation, but it is a
standalone program that can be executed at any time. During system
generation, you designate the Cp-owned volumes by coding the
created during system generation. If, at some time after system
generation, you
partial system generation and reassemble those files using the GENERATE
system generation.
discontiguous saved segment, called
those changes.
reset the name of the shared segment by issuing a
use an alternate segment, indicate the alternate segment on a
attached. If you do not want
editor,
correspond to a named saved segment.