CA Dynam for VSE User Guide

Using DYNACC
The service module is loaded at runtime into dynamically acquired storage.
Under VSE, the service modules may be preloaded into the Shared Virtual
Area. Alternatively, they will be loaded at runtime into the partition GETVIS
area by DYNACC. The Version 2 service module, CACUDA20, is approximately
12K in size. It acquires a further 16K or more for catalog buffers and work
areas, depending on the options specified by the caller.
Linkage Conventions
DYNACC is called using standard IBM linkage conventions.
Linkage register usage on entry is as follows:
R1
R13
R14
R15
points to the parameter list.
points to a standard format save area (XL72).
points to the return address in the calling program.
points to the entry point in DYNACC
On return, R15 will contain a return code and the condition code is set to
facilitate error processing. The return code is also stored in a field in the
DYNINFO header (DYNRTCOD) for use by high-level languages.
Parameter List Contents
The parameter list is in IBM standard format as generated by the Assembler
CALL macro and equivalent higher level constructs. Assembler programmers
should use the CALL macro to ensure strict adherence to linkage conventions,
upon which DYNACC relies.
The parameter list contains one entry, as follows:
+0 A(DYNINFO) - address of DYNINFO
The high-order bit should be on to denote end-of-list. This ensures
compatibility should a future release support additional calling parameters.
Chapter 10: Accessing the Catalog 10–3