The requirements for the caller are:

Ensure that the code for the SVC routine added to the SVC table has the correct attributes for the type of SVC specified.

The caller must include the CVT mapping macro.

None.

Before issuing the SVCUPDTE macro, the caller does not have to place any information into any register unless using it in register notation for a particular parameter or using it as a base register.

After the caller issues the macro, the system might use some registers as work registers or might change the contents of some registers. When the system returns control to the caller, the contents of these registers are not the same as they were before the macro was issued. Therefore, if the caller depends on these registers containing the same value before and after issuing the macro, the caller must save these registers before issuing the macro and restore them after the system returns control.

On input, register 13 must contain the address of a 72-byte save area.

None.

The SVCUPDTE macro is written as follows:

The parameters are explained as follows:

num

Specifies the number of the SVC that is being inserted or deleted.

,REPLACE

,DELETE

Specifies the function to be performed. REPLACE indicates that an SVC table entry is to be inserted in the SVC table. This could be a new SVC or a replacement for an existing SVC. DELETE indicates that the specified SVC number is to be deleted from the SVC table.

If you issue an SVC instruction with a deleted or undefined SVC number, the program abnormally ends with a system completion code of X'Fnn' (nn is the operand of the SVC instruction, in hexadecimal). However, if you issue an SVCUPDTE macro using the DELETE parameter and specify a previously deleted SVC number, no abnormal end results.

,EXTRACT

Indicates that the user has supplied an EP or EPNAME and wishes to have the SVC number of that routine returned in register 0. The num parameter is not valid with this option.

,EXTRACTANY

Indicates that the user has supplied an EP or EPNAME and wishes to have the SVC or extended SVC number of that routine returned in register 0.

For a non-extended SVC

Bit 0 of register 0 has a value of 0. Bits 24–31 contain the SVC number.

For an extended SVC

Bit 0 of register 0 has a value of 1. Bits 16–23 contain the ESR number. Bits 24–31 contain the SVC number.

The num parameter is not valid with this option.

,TYPE=1

,TYPE=2

,TYPE=3

,TYPE=4

,TYPE=6

Specifies the SVC type for a REPLACE request. See the topic “Programming Conventions for SVC Routines” in z/OS MVS Programming: Authorized Assembler Services Guide for information concerning the characteristics and restrictions for each type of SVC.

,EP=addr

Specifies the entry point address of the SVC routine. The addressing mode of the entry point is defined by bit 0 of the entry point address of the SVC routine. If bit 0=1, the SVC routine will be entered in 31-bit addressing mode; if bit 0=0, the SVC routine will be entered in 24-bit addressing mode.

,EPNAME=entry-name

Specifies the entry name of the SVC routine. The entry name must be the load module name or alias of a module in LPA or the entry name of a module link edited into the nucleus. The AMODE of the SVC routine is determined when the SVC is link edited.

When entry-name is IGCERROR:

• When ESR=esr is not specified, the SVC routine results in a Fxx abend when SVC xx is issued, where xx matches num.
• When ESR=esr is specified, the SVC routine results in abend 16D-8 when SVC num with routing code esr is issued.

,LOCKS=(lname,lname,...)

Specifies the lock(s) required when the SVC routine executes. The lock(s) specified can be CMS or LOCAL. This parameter is valid only with REPLACE.

Note:

1. TYPE=1 must not specify LOCAL.
2. TYPE=6 cannot specify any locks.
3. TYPE=2, 3, or 4 must specify LOCAL if CMS is specified.

,APF=YES

,APF=NO

Specifies whether or not the invocation of the SVC is to be restricted to authorized programs. This parameter is valid only with REPLACE.

,AR=YES

,AR=NO

Specifies whether or not the SVC can be issued by a program in access register mode. If you specify NO, a program that issues the SVC while in access register mode abends with a completion code of X‘0F8’. This parameter is valid only with REPLACE.

,NPRMPT=YES

,NPRMPT=NO

Indicates whether or not the SVC can be preempted for I/O interruptions.

,RELATED=value

Provides information to document the macro by relating the function performed to another service or function. The format can be any valid coding value that the user chooses.

,ESR=esr

Specifies the extended SVC routing number of an extended SVC. You may supply a decimal number or a value in register (2) - (12). When you supply an explicit SVC number, the ESR parameter is only allowed with SVC numbers 109, 116, 122, and 137. When you provide the SVC number in a register, the ESR specification is ignored if the SVC number is not 109, 116, 122, or 137. This parameter is not valid with EXTRACT. When ESR is specified, the TYPE parameter is only used to validate other parameters, because each extended SVC has a predefined type that cannot be changed.

Note: When using SVC screening with the ESR parameter, the system ignores the screening information associated with the ESR number itself (for example, 109). The system only uses screening information associated with the routing code.

,USEECVT=YES

,USEECVT=NO

You may use this optional parameter to avoid some system processing. Specifying YES allows the system to locate the SVCUPDTE service with a pointer in the ECVT instead of using the NUCLKUP service. You must be running in AMODE 31 to use this parameter. This parameter also requires the IHAECVT mapping macro.

None.

When the SVCUPDTE macro returns control to your program, GPR 15 contains a hexadecimal return code.