Interface to the exit

The exit is invoked in task mode, problem state, and key 8; the task is APF-authorized. The exit must restore this state before returning to its caller.

Control is passed to the exit using the BAL instruction. The exit must return to the caller using the address and addressing mode passed to it in general register 14.

When the exit is entered, register 1 contains the address of the parameter list. Each address in this list is used to locate the parameter value. These parameters are passed to the exit:

PDSNAME   DS   CL44     (data set name)
PMIGR     DS   CL1      (Y=MIGRATED data set N=otherwise)
PVSAM     DS   CL1      (Y=VSAM data set N=otherwise)
PTAPE     DS   CL1      (Y=tape N=otherwise)
PRETCOD   DS   F        (return code)