Interface to the exit

This exit is invoked in task mode, problem state, and key 8 and the job-step task is APF-authorized. The active task runs with the same access authority as the job-step task. 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 its caller using the address and addressing mode passed to it, usually register 14.

The exit is entered in AMODE 31 but must switch to AMODE 24 before performing any input or output operations, and then switch back to AMODE 31 before returning to the caller.

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: