z/VM: CP Commands and Utilities Reference - z/VM - IBM

Usage Notes
inserted into the virtual machine registers m through n, which are first initialized
to binary zeros. For further information, refer to the DEFSYS command. If you
enter a string too large to fit in the designated registers, an error message is
issued, and the command is not processed. If you specify PARM followed by all
blanks or if you omit PARM, the virtual machine registers specified by the
PARMREGS option on the DEFSYS command contains all zeros.
If you are IPLing an NSS that was defined with the PARMREGS=NONE option
on the DEFSYS command, specifying the PARM option results in an error
message being issued and in the command not being processed.
If you are IPLing an NSS that was defined without the PARMREGS=m-n option
on the DEFSYS command, the parameter string is inserted into the virtual
machine registers 0 through 15. The registers are not first initialized to binary
zeros. If you specify PARM followed by all blanks or if you omit PARM, the
virtual machine registers are unchanged.
1. When the IPL command is entered from the virtual machine console as the
first or only command on a CP command line (that is, while TERMINAL MODE
is CP, or CP READ is displayed or the command line begins with #CP), VM
attempts to break out of certain wait conditions that might exist. Thus the IPL
command may be entered to cause breakout of certain virtual machine wait
conditions.
The breakout attempt occurs when the IPL command is entered, not when the
command is processed. Command errors do not prevent the breakout attempt.
In some cases a breakout resets the virtual machine.
2. If you want to use the AUTOCR, BATCH, NOSPROF, INSTSEG, or SAVESYS
parameters of the IPL command, you must have PARMREGS=0-15 in the
DEFSYS command for the CMS named saved system.
3. IPL simulates the LOAD operation on the real system console. The specified
virtual device is accessed, and the required input/output operations are
performed to retrieve the IPL data. This does not pertain to named saved
systems.
4. Optionally, you can stop the IPL procedure after loading the virtual PSW. Also,
you can pass parameters to the virtual machine’s general registers. When the
simulated load function is complete, CP initiates execution of the virtual
machine by loading the IPL PSW, which was stored during the simulation
process.
5. If you enter ipl system_name or ipl vdev clear, the IPL command performs a
system-reset-clear function on your virtual machine as if the SYSTEM CLEAR
command were processed. If you enter ipl vdev noclear or if you enter ipl
vdev and NOCLEAR is taken as the default, the IPL command performs a
system-reset-normal function on your virtual machine as if the SYSTEM
RESET command were processed. The effects of a system-reset-normal or
system-reset-clear function are described in detail in the description for the
SYSTEM RESET and SYSTEM CLEAR commands.
6. Any logical lines following the IPL command are ignored because execution of
the IPL command transfers control from the CP environment to the virtual
machine environment.
7. The IPL sequence for the program that you want to IPL must use only format 0
CCWs.
8. After you enter the IPL command, the pseudo page fault facility is deactivated.
To activate (or reactivate) the pseudo page fault facility, you must enter the
IPL
Chapter 2. CP Commands 503