Register Usage at Entry:

Common Parameter List (mapped by UXPARM macro in CAI.CBTDMAC)

R1

Contains the parameter list, in the following format:

+0: Contains the address of the parameter list of the GCMDELXT routine.
+4: Contains the address of the communication word of the GCMDELXT routine. During its initialization call, the routine sets the contents of the word. The contents are passed unchanged for all subsequent calls.
+8: Contains the full word of flags used to pass status information to the routine.
+C: Contains the global communication word.

R13

Contains the address of the standard save area.

R14

Contains the CA MIM return address.

R15

Contains the GCMDELXT entry point address.

Note: All other registers are undefined.

GCMDELXT Exit-specific Parameter List (mapped by GCMDELXP macro in CAI.CBTDMAC)

+0: (Fullword reserved for pre-Version 4.1 and above user exit compatibility)
+4: Fullword containing the address of the four-byte user data area for this message. The contents of the user data area are retained for the life of the action message.
+8: (Eight bytes reserved)
+10: Eight-byte job name of message issuer.
+18: (Eight bytes reserved for pre-Version 4.1 and above user exit compatibility)
+20: Eight-byte time stamp of message.
+28: (One byte reserved)
+29: Three-byte DOM ID of message. Provided for message identification purposes only. Issuing the DOM SVC from in the GCMDELXT exit causes unpredictable results. The GCMDELXT can issue a return code to instruct CA MIC to delete the message.
+2C: (Fullword reserved)
+30: Twelve-byte message name of the action message (that is, IEF233A), left justified and padded on the right with blanks.
+3C: (Twelve bytes reserved)
+48: Eight-byte GCMDELXT user exit parameter list eye catcher “GCMDELXT.”