Establishing addressability to the parameter area
The recovery routine also must establish addressability to the
parameter area passed by the mainline routine. To determine the location
of the parameter area:
- If an SDWA is present, the recovery routine checks either the contents of SDWAPARM or the contents of GPR/AR 2. GPR 2 contains the address of the parameter area, and for AR-mode callers, AR 2 contains the ALET.
- If no SDWA is present, the recovery routine checks the contents of GPR/AR 2. GPR 2 contains the address of the parameter area, and for AR-mode callers, AR 2 contains the ALET.
Refer to Setting up, passing, and accessing the parameter area for further detail on accessing the parameter area.
The following are examples of information a mainline routine can
pass to a recovery routine through the parameter area:
- A dynamic storage area
- An input parameter list (that is, a parameter list that might have been passed to the mainline routine)
- The addresses of important data areas.