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

STORE Guest Storage (z/Architecture)
Usage Notes
1546 z/VM: CP Commands and Utilities Reference
INDEXnn
stores data in guest storage, using the specified starting address (hexloc1) as a
displacement from the address in the specified register. The specified register
may be a decimal number from 0 to 15 or a hexadecimal number from 0 to F.
% indicates 31-bit address indirection. Indirection means that the contents of the
specified address are used instead of the address itself. In this case, the 31 bits
at the specified address (the high-order bit is turned off) are used as the new
address for the Store command.
& indicates 64-bit address indirection. Indirection means that the contents of the
specified address are used instead of the address itself. In this case, the 64 bits
at the specified address are used as the new address for the Store command.
The indirect address specified here (following INDEX and BASE) is determined
after BASE and INDEX are applied.
A maximum of 16 indirection characters can be specified.
data
is the data you want to place in storage. It takes on different meanings,
depending on the type of STORE you are performing (N, S, K, or U). See the
descriptions of each of these operands for the meaning of data.
1. An attempt to store at an address in a protected page, or to change the key at
an address in a protected page, results in an error message. A protected page
is a page of read-only storage.
2. The operands HOME, AREGareg., ALEThexword., and ALEThexword.ALraddr.
are valid only if the the virtual machine is an ESA virtual machine.
3. When you use the operand ALEThexword.ALraddr., the primary list bit in the
ALET is ignored.
4. The operands L, PRI, SECO, HOME, ASTEraddr., ASCEasce., ASNasn.,
AREGareg., ALEThexword., and ALEThexword.ALraddr. use the access
register translation (ART), the ASN translation or the dynamic address
translation (DAT) processes. These contain special case translation processes
including the following:
v ALET 0 always indicates the current primary address space designated by
the ASCE in guest control register 1, regardless of the current contents of
the dispatchable-unit access list.
v ALET 1 always indicates the current secondary address space designated
by the ASCE in guest control register 7, regardless of the current contents
of the dispatchable-unit access list.
v Access register 0 is always treated as containing the ALET 0. The contents
of access register 0 are not used during ART processing.
v General register 0 is always treated as containing the value 0 when used as
the base or index register. The contents of GR 0 are never used.
5. The BASE operand is primarily intended for use in conjunction with the L
operand. It allows a user to modify the storage his virtual machine uses in one
less step than would otherwise be possible. Without the BASE operand, a user
may need to display the contents of a general register, then add the
displacement, and then enter the STORE command to modify storage his
program is using. With the use of access registers, the BASE option allows the
user to modify storage without needing to know whether his program is
currently in access register mode. This is done automatically for him by CP.