User Exits › EXIT Routine Programming Considerations › GCMSRCXT Exit › Register Usage at Entry:

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 GCMSRCXT routine.

+4

Contains the address of the communication word of the routine. During its initialization call, the routine sets the contents of the word. The contents are passed unchanged for all subsequent calls to this routine.

+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 return address for CA MIM.

R15

Contains the entry point address for the GCMSRCXT routine. All other registers are undefined.

GCMSRCXT Parameter List (mapped by the GCMWTOXP macro in CAI.CBTDMAC)

+0

(Fullword reserved for pre-Version 4.1 and above user exit compatibility)

+4

Fullword containing the address of the message text. Modifiable by the user exit.

+8

One-byte unsigned integer containing the length of the message text. The GCMSRCXT cannot change the length of the message text. If you remove text, then replace it with blanks.

+9

(Seven bytes reserved)

+10

Eight-byte job name of WTO issuer.

+18

Twelve-byte message name (that is, IEF233A), left justified, padded on right with blanks.

+24

Two bytes containing the z/OS MCS flags for this WTO.

+26

Two bytes containing the z/OS descriptor codes for this WTO.

+28

Sixteen-bytes containing the z/OS route codes for this WTO.

+38

(One byte reserved)

+39

(One byte reserved)

+3A

One-byte field containing the following flag bits:

B'10000000' -

WTO issued on a z/OS system (always on z/OS systems)

B'01000000' -

Message issued on a z/VM system (always off z/OS systems)

B'00111111' -

(reserved)

+3B

(Five bytes reserved)

+40

Four-byte message ID of this message on the originating system. This is provided for message identification and tracking only. Do not issue the DOM SVC in the GCMSRCXT exit as it causes unpredictable results. The GCMSRCXT can issue a return code to instruct CA MIC to DOM (delete) the message.

+44

Eight-byte system name of this system, if available. Otherwise, this field contains X'00's.

+4C

Eight-byte sysplex name of which this system is a member, if any. Otherwise, this field contains X'00's.

+54

One-byte field containing the following flag bits:

B'10000000' - four-byte console ID present at offset +X'58'
B'01111111' - (reserved)

+55

(Three bytes reserved)

+58

Fullword containing the four-byte console ID to which this message is destined, if message is console directed. Otherwise, this field contains X'00's if this message is not console directed, or if bit X'80' is off at offset +X'54' in the parameter list.

+84

Four bytes containing the Extended Message Modification Bytes for requesting to change message color, highlighting, and intensity (see GCMWTOXP mapping macro).

+88

(Eight bytes reserved)

+90

Eight-byte eye catcher containing GCMWTOXP.

+98

Eight-byte eye catcher containing GCMSRCXT.