User ID Security Exit Support › System Initialization Parameter List

System Initialization Parameter List

On entry to the security exit, Register 1 points to a list of ten full words, as shown in this diagram.

The contents of the parameter list are as follows:

Word 1

Is a fullword containing the address of function code F‘0’.

Word 2

Is set to zero.

Word 3

Is a 24-character area containing the following:

• The eight-character primary ACB name field (padded to the right with blanks if necessary). The primary ACB name is as specified on the PRI JCL initialization parameter.
• Four blanks
• The four-character system domain ID as coded on the NMDID initialization parameter. If the NMDID parameter is omitted, the domain ID defaults to one of the following values:
  • The first four characters of the primary ACB name used by your region (blank padded if necessary)
  • The ACB name itself if less than five characters long.
• The four-character system user prefix as coded on the NMSUP initialization parameter. If not coded, the value defaults to the NMDID value.
• The four-character product version, for example, V5.1.

These characters are passed to the exit to identify the region that is executing and can be regarded as the user ID of the system. The exit can use this value to determine whether, for example, it is a production region.

Word 4

Is the address of two full words:

• First word can contain any value. This value is returned in the system closedown call, so it can be used as a region correlator. The exit can use this word to relate this region to a set of control blocks or other information maintained by the exit in relation to the region.
• Second word is the region user token (UTOKEN) if one is available.

Words 5 through 10

Are set to zeros.

Return Codes from Initialization Call

The exit must return a completion code in Register 15 on return. Successful initialization must be signified by return code F‘0’. Your product region terminates if any other value is returned in Register 15 on completion of this call.