Service_name

For AMODE 31 callers, the name that the assembler understands is the name of a module in the form BPX1xxx, where xxx is a three-character symbol unique to the service. (In a few cases, where both standard and nonstandard versions of a service exist, the standard version of the service is in the form BPX2xxx.) AMODE 64 callers use the name of a module in the form BPX4xxx. (See Using callable services in a 64-bit environment.)

Modules are invoked in one of the following ways:

A program can load a module, and then branch to the address where it was loaded.
When you link-edit a program, you can link to the linkage stub. The program can issue a call.
The linkage stubs are contained in SYS1.CSSLIB. You can specify SYS1.CSSLIB in the //SYSLIB statement of the JCL that is used to invoke the linkage editor. This causes the addresses of all required linkage-assist routines to be automatically resolved, and saves you the trouble of having to specify individual linkage-assist routines in INCLUDE statements.

For BPX4xxx stubs, you need 64-bit binder support to do the link-edit. See Using callable services in a 64-bit environment.
You can include in the code the system control offset to the callable service. See System control offsets to callable services for information on how to use this linkage.

For information about using callable services in AMODE 64, see Using callable services in a 64-bit environment.