Description

The Logical Parmlib Concatenation is a set of up to 10 partitioned data sets defined by PARMLIB statements in the LOADxx member of either SYSn.IPLPARM or SYS1.PARMLIB which contains many initialization parameters in a pre-specified form in a single logical data set, thus minimizing the need for the operator to enter parameters. SYS1.PARMLIB makes the 11th or last data set in the concatenation and is the default logical parmlib if no PARMLIB statements exist in LOADxx.

The objective of this support is to allow installations to partition access to parmlib and isolate members customized by an installation from IBM® maintenance and product level upgrades. The logical parmlib is established during IPL and is used by Master Scheduler Initialization and IEFPRMLB. There is a new SETLOAD command that allows you to switch from one logical parmlib to another without an IPL. The IEFPRMLB macro allows you to access the logical parmlib.

Use the IEFPRMLB macro to:

Allocate the logical parmlib data set concatenation
Unallocate the logical parmlib data set concatenation
Read a logical parmlib data set
Retrieve information about which data sets make up the logical parmlib

The four functions for the macro are:

IEFPRMLB REQUEST=ALLOCATE allocates the logical parmlib via DDname.
IEFPRMLB REQUEST=FREE unallocates the logical parmlib via DDname.
IEFPRMLB REQUEST=LIST retrieves information about the logical parmlib data set concatenation.
IEFPRMLB REQUEST=READMEMBER reads a specified member of an already allocated logical parmlib and returns its contents in an input buffer.

Environment

The requirements for the caller are:

Environmental factor	Requirement
Minimum authorization:	Problem state and PSW key 8-15
Dispatchable unit mode:	Task
Cross memory mode:	PASN=HASN=SASN
AMODE:	24- or 31-bit
ASC mode:	Primary or access register (AR)
Interrupt status:	Enabled for I/O and external interrupts.
Locks:	No locks may be held.
Control parameters:	Control parameters must be in the primary address space.

Programming requirements

The caller should include the IEFZPRC mapping macro to get return and reason code equates for all the functions.

If you are going to use the read, message or list buffers, then you should include the IEFZPMAP mapping macro to get their mappings.

Restrictions

The caller may not have an EUT FRR established.

Input register information

Before issuing the IEFPRMLB macro, the caller does not have to place any information into any register unless using it in register notation for a particular parameter, or using it as a base register.

Output register information

When control returns to the caller, the GPRs contain:

Register: Contents
0: Reason code when GPR15 is not 0
1: Used as a work register by the system
2-13: Unchanged
14: Used as a work register by the system
15: Return code

When control returns to the caller, the ARs contain:

Register: Contents
0-1: Used as work registers by the system
2-13: Unchanged
14-15: Used as work registers by the system

Some callers depend on register contents remaining the same before and after issuing a service. If the system changes the contents of registers on which the caller depends, the caller must save them before issuing the service, and restore them after the system returns control.

Performance implications

None.