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. The following parameters are passed to the exit:

EQQUXGDG parameters

PJOBNAM    DS   CL8   (job name)
PSTEPNUM   DS   CL3   (step number)
PSTEPNAM   DS   CL8   (step name)
PPROCSTE   DS   CL8   (proc step name)
PDDNAME    DS   CL8   (DD name)
PROOT      DS   CL35  (GDG root)
PABSOLUT   DS   CL8   (GDG absolute value)
PSIGN      DS   CL1   (GDG relative number sign)
PRELNUM    DS   CL7   (GDG relative number)
PRETCODE   DS   F     (return code)   
PJOBNAM
Job name of the JCL that is going to be run.
PSTEPNUM
Step number (expressed in character format) where the GDG data set to be overwritten is located.
PSTEPNAM
Step name where the GDG data set to be overwritten is located.
PPROCSTE
Proc step name where the GDG data set to be overwritten is located.
PDDNAME
DD name where the GDG data set to be overwritten is located.
PROOT
GDG Root o f the GDG data set that is going to be overwritten.
PABSOLUT
Value (GnnnnVnn) that is going to be used to overwrite the input GDG data set.
PSIGN
The sign (+ or – or blank) of the relative number of the GDG data set to be overwritten.
PRELNUM
Relative number (expressed in character format) of the GDG data set to be overwritten.
PRETCOD
Return code set by the exit:
0
Execute the overwriting.
4
Do not execute the overwriting.