Input Parameters

Input parameters for the IEFJSVEC service are:

VTSPL
JSBVT — both fixed and variable sections

VTSPL Contents: Your program sets the following fields in the VTSPL control block on input:

Field Name

Description

VTSID

Identifier 'VTSP'

VTSLEN

Length of the VTSPL (VTSSIZE) control block

VTSVER

Version number of the VTSPL (VTSCVER) control block

VTSCONID

The 1-byte console ID of the console that the subsystem initialization routine issues messages to. If your program sets this field to zero, the VTSCNSID field is used.

This field exists for versions of MVS™ previous to SP410. IBM® recommends that you specify a 4-byte console ID as defined by the VTSCNSID field.

VTSFLAGS

Flags

VTSGLOAD — load-to-global indicator.
To eliminate the need to have subsystem function routines reside in LPA, the subsystem can request that IEFJSVEC issue a load-to-global for those function routines by setting the VTSGLOAD indicator. If load-to-global is used for the subsystem function routines, the function routines are loaded into pageable CSA and the loaded routines are associated with the requesting task. When the task ends, the module's use count is reduced by the number of outstanding LOADs. When the module's use count reaches zero, the module is deleted, leaving an invalid function routine address in the SSVT. Therefore, the load-to-global option should only be used by programs running under a task that never ends. For example, if IEFJSVEC is invoked by the subsystem initialization routine which is given control out of early system initialization (that is, those subsystem initialization routines specified in IEFSSNxx parmlib members) the requesting task is the master scheduler, which never goes away.

If you set the load-to-global indicator, all function routines which are specified on a single request to IEFJSVEC are loaded into pageable CSA. If you want to have some function routines loaded into CSA and others that are not, issue separate invocations of IEFJSVEC, one with the VTSGLOAD indicator set and the other with the VTSGLOAD indicator not set. Because your subsystem can only have one SSVT, for subsequent calls to IEFJSVEC, you need to use the enable function code request option available through the IEFJSVEC service. See Enabling Your Subsystem for New Functions for more information.

VTSREQ

Request flags — defines the operation that this call performs

VTSCREAT — SSVT build indicator

VTSNAME

Subsystem name. The name of the subsystem for which the SSVT is being built. The subsystem name can be up to four characters. It must be left-justified and padded to the right with blank (X'40') characters.

VTSSVTD

Address of SSVT table data (mapped by IEFJSBVT)

VTSCNSID

4-byte console ID that the SSI uses for any messages issued on this invocation of IEFJSVEC. If this field is set to zero, the messages go to the master console.

Provide a CART and a console ID if IEFJSVEC is invoked while running under a command processor. For example, if a subsystem is initialized through START command processing. See z/OS MVS Programming: Authorized Assembler Services Guide for information on how to obtain the CART and console ID from the command input buffer (CIB) control block.

VTSCART

Command and response token (CART). If a CART is provided, the SSI uses it for any messages it issues for this invocation of IEFJSVEC.

Set all other fields in the VTSPL control block to binary zeros.

JSBVT Contents — Fixed Header Section: Your program sets the following fields in the JSBVT control block on input:

Field Name: Description
JSBID: Identifier 'JSBV'
JSBLEN: Length of the JSBVT (fixed header section) control block
JSBVERS: Version number of the JSBVT (JSBCVERS) control block
JSBFUN: Number of function routines specified in this table of data
JSBSPL: Subpool number from which the SSVT is to be built. Note that the system uses the mode and key of the caller to access the SSVT and invoke the function routines.
JSBMAXFR: Maximum number of function routines you expect the subsystem to need

Set all other fields in the fixed header section of the JSBVT control block to binary zeros.

JSBVT Contents — Variable Length Section: The JSBVT fixed header is followed by a variable length function routine data area (one for each function routine). Your program sets the following fields on input:

Field Name: Description
JSBLGTH: Length of this function routine's data area and function code area (also see JSBFCOD)
JSBNME: Name of the function routine. The function routine name can be up to eight characters. It must be left-justified and padded to the right with blank (X'40') characters.
JSBNUM: Number of function codes the function routine supports

JSBVT Contents — Variable Length Section: The function routine data area is follow by a variable length function code area (one for each function routine). Your program sets the following fields on input:

Field Name: Description
JSBFCOD: Function code (repeat if more than one function code is supported by the same function routine). The value specified for each function code must be in the range 1-255.