1-182 IBM VM/370 System Logic and Problem Determination--Volume 1
CP Program Organization
Use of the AnnotatedFlow Diagram
The following text sections, which describe eachmajor CP function, are
annotated flow diagraBs. These diagrams, consisting of logic labels andcommentary, describe the general flow and use of CP logic modules and
their relationship to other modules whileperforming a specific function
or task. The annotated flow diagrams do not contain references to errormessages, abnormal termination conditions, or most control block field
labels. This avoids complexity and makes the general logic ofCP and
its related tasks more understandable to the user.With "understandability" as the key, obtuse and complex logic that is used
for obscure and seldom used functions is not described. Also the flow
diagram does not indicate nor describe every entry point encountered in
a function. Nor do the diagrams illustrate the innumerabletimes that
commonly used modules are utilized.DftKFRE and DftKCVT, the obtaining
and returning of free storage and the number base conversionmodules are
such examples. Annotated flow diagrams are arranged by function and
subfunction. Titles for these functions and subfunctions also precede
annotated flow text and labels. The text in the charts is prefixed by
underscored and capitalized entry points and labels. Entry points are
indicated by seven or eight characters; the first three characters are
DMK. Labels are indicated by prefixing with acomma and the
six-charactermodule identification.
The annotated flow diagrams in this section do not reflectV!/370 use
of the MSS. If there is anMSS attached to the VM/370 system, consult
Appendix B in this volume for flow diagrams of those functions that
utilize theMSS (such as logging on a virtual machine that has a mimidisk defined on an MSS 3330V voluae}0
Note: Annotated flow diagrams are not to be construed as tracematerial. The dynamics of CP operations preclude the use of the annotated flow
diagrams, as they areshown in this manual, as traces of CP functions. VM/370 CP Interruption Processing SVC INTERRUPTIONS - PROBLEM STATE DMKSVCIN --Entry for SVC problem mode
replaced.DMKCFMBK interruptions from problem or supervisor states. For
andADSTOP (SVC X 'B3'), the overlaid instruction is ---console function mode is entered. DMKSVCIN SVC 76 (X'4C') check for valid parameter passing. SCP used in the virtual machine by examining passed parameters in RO and R1. performed. DMKIOEVR CP Method of operation and Program Organization 1-183
Use of the Annotated
The following text sections, which describe each
annotated flow diagraBs. These diagrams, consisting of logic labels and
their relationship to other modules while
or task. The annotated flow diagrams do not contain references to error
labels. This avoids complexity and makes the general logic of
its related tasks more understandable to the user.
for obscure and seldom used functions is not described. Also the flow
diagram does not indicate nor describe every entry point encountered in
a function. Nor do the diagrams illustrate the innumerable
commonly used modules are utilized.
and returning of free storage and the number base conversion
such examples. Annotated flow diagrams are arranged by function and
subfunction. Titles for these functions and subfunctions also precede
annotated flow text and labels. The text in the charts is prefixed by
underscored and capitalized entry points and labels. Entry points are
indicated by seven or eight characters; the first three characters are
DMK. Labels are indicated by prefixing with a
six-character
The annotated flow diagrams in this section do not reflect
of the MSS. If there is an
Appendix B in this volume for flow diagrams of those functions that
utilize the
Note: Annotated flow diagrams are not to be construed as trace
diagrams, as they are
replaced.
and
