The input is a parameter list that describes the volume DFSMShsm is releasing and the actions required. The parameter list is similar to the one DFSMShsm passes to ARCTVEXT, except that DFSMSrmm's parameter list handles only a single volume at a time.

On entry, register 1 contains a pointer to an 8-byte field. The first 6 bytes are the volume serial number to be processed and the last 2 bytes are flag bytes. The contents of the flag bytes are the flag bytes DFSMShsm passes to the ARCTVEXT exit. See z/OS DFSMS Installation Exits for information on ARCTVEXT.

On entry, register 13 contains the address of a standard 18 word save area and register 14 contains the return address.