The installation exit for each service gets the address of the exit parameter block (EXPB) in register 0. ICSF obtains and initializes an EXP for every service call. Figure 1 illustrates the contents of register 0, and Table 1 illustrates the EXPB for the service exits.
Register 1 contains the address of an address list. Each address in the list points to a parameter. Parameters describes the service parameter list. The parameters the exit receives are the same parameters that are passed on the call to the service. For more information about the parameters for each service, see z/OS Cryptographic Services ICSF Application Programmer's Guide.
Figure 1. EXPB control block in the service exits