Environment upon entry to user's exit routine

When control is passed to your routine, the register contents are as follows:

Register 0:: Used as a work register by the system.
Register 1:: Address of the PIE or EPIE for the task that caused the interruption.
Registers 2-13:: Unchanged.
Register 14:: Return address.
Register 15:: Address of the exit routine.

The access registers and linkage stack have the values that were current at the time of the program interruption. Both SPIE and ESPIE exits always receive control in primary ASC mode.

The SPIE or ESPIE routine must maintain the return address supplied in GPR 14. The routine does not have to place any information in any of the return registers for use by the system.