IPL.HELPCMD.D1

IPL                                                      CP Privilege Class: G
 
Use the IPL =ommand to simulate an initial program load function for a
virtual machine. The format of the 1PL command is:
+---------+------------------------------------------------------------------+
| IPL     | { vaddr [cylno ] [ CLear | NOCLear ] [ STOP ] }                  |
|         |  [PARM {p1 p2 .t.t.t l]
+---------+------------------------------------------------------------------+
where:
 
vaddr [volno] [ CLEAR | NOCLear ] [ STOP ]
        simulates the IPL function when loading by device address.
vaddr
        is the virtual address (cuu) of the device that contains the
        nucleus to be loaded.
cylno
        is the cylinder containing the IPL data. If this operand is
        specified, CP loads the IPL data from the specified virtual
cylinder
        instead of from virtual cylinder zero. Virtual cylinder zero
        is the default when cylno is not specified. This operand is valid
        only for virtual direct storage devices.
CLEAR
        sets the virtual storage space to binary zeros before the
        operating system is loaded. This operand is invalid if you
        specify a systemname in the IPL command line.
NOCLEAR
        allows the contents of your virtual storage space to remain
        unchanqed prior to program load. This operand is invalid if
        you soecify a systemname in the IPt command line.  NOCLEAR is
        the default if you IPL by device (vaddr).
STOP
        halts the virtual machine during the IPL procedure just before
        the initial PSW is loaded. It provides the virtual simulation
        of the IPL procedure for a real machine in instruction step mode.
        The STOP operand is invalid if systemname is specified in the IPL
        command.  When the virtual machine stops, you can issue CP commands.
        For example, if you are loading OS or OS/VS into your virtual machine,
        you can use CP commands to store data into low storage, to load an
        alternate nucleus, or to alter the apparent size of virtual storage.
        to restart the virtual machine, issue the BEGIN command.
systemname
        simulates the IPL function when loading a named system that
        was previously saved via the SAVESYS command. It is loaded
        into virtual storage and qiven control.  For information about
        saved systems, see the VM/370 System Programmer's Guide.
        Note: You cannot load a shared system or one that uses
        discontiguous saved segments into a virtual machine running in
        the V=R area.  An attempt to do so results in an error message.
PARM { p1 p2 ... ]
        passes up to 64 bytes of data (excluding the first blank
        character after the keyword, PARM, but including all other
        embedded blanks) to your virtual machine's general registers
        (4 bytes per register), starting with the high order byte of
        general register 0. Since the registers are not cleared
        before use, the PARM value should be some multiple of 4 bytes
        to avoid having extraneous characters present in the low order
        positions of the register. For example, you could key in
 
        PARM CMS~
 
        where ~ represents a blank to ensure that the low order
        positions of register 0 contain a hexadecimal 40. Whenever
        PARM is specified, the remaining characters in the command
        line are treated as parameters to be passed to your virtual
        machine; therefore, PARK must be the last operand entered on
        the command line.