Whenever a breakpoint is encountered, a program check occurs. The message DMSDBG7281 DEBUG ENTERED BREAKPOINT II AT IIIIX appears on the terminal. Follow the same procedure to enter subcommands
and resume processing as with a regular program check.An external interrupt, which occurs when the CP issued, causes CMS to enter the debug environment. DMSDBG7281 DEBUG ENTERED EXTERNAL INTERRUPT EITERNAL co.mand is
The message
appears on the console.Any of the DEBUG subcommands may be issued. To
exit from the debug environment after an external interrupt, use GO.While CMS is in the debug environment, the control words and low
storage locations contain the debug program values. The debugprogram saves the control words and low storage contents (X'OO' through X'100') of the interrupted routine at location I'CO'. Nucleus Load Map
Each time theCMS resident nucleus is loaded on a DASD and an IPL can be
perforaed on thatDASD, a load map is produced. Save this load map. It
lists the virtual storage locations of nucleus-resident routines and
work areas. Transientmodules will not be included in this load map. When debugging CMS, you can locate routines using this map. The load map aay be saved as a disk file and printed at any time. A copy of the nucleus load map is contained on the system with file
identification of'filename NUCMAP.' To determine the filename, issue
thecommand LISTFILE * NUCMAP *
To obtain a copy of the current nucleus load map, issue thecommand PRINT filename NUCMAP filemode Figure 11 shows a sample CMS load map. Notice that the DEBUG work
area(DBGSECT) and DKSINM module have been located.
66IBM VM/370 System Programmer's Guide
and resume processing as with a regular program check.
The message
appears on the console.
exit from the debug environment after an external interrupt, use GO.
storage locations contain the debug program values. The debug
Each time the
perforaed on that
lists the virtual storage locations of nucleus-resident routines and
work areas. Transient
identification of
the
To obtain a copy of the current nucleus load map, issue the
area
66