The contents of the registers on exit should be:

R0-1

Irrelevant

R2-13

Same as entry

R14

Return address

R15

Irrelevant

Use the RC= parameter on the ARETURN macro to specify normal return or dummy exit as follows:

RC=0

Normal return

RC=4

Reserved

RC=8

Reserved

RC=12

Reserved

RC=16

Dummy exit routine; this exit will not be called again until the system is restarted.