Input

In addition to the input considerations described in Conditions on Entry to an IPCS Exit Routine, the following special input considerations apply to TCB exit routines.

On entry to a TCB exit routine, register 1 points directly to the IPCS task variable (ABDPL data area).

Field ADPLASID identifies the address space in which the TCB resides whenever the address space resides in virtual storage. When the address space resides in an address space other than virtual storage, field ADPLASID is set to zero.
This field can be set by TCB exit routines to specify an ASID before t he exit routines invoke the storage access service to retrieve virtual storage, or when the exit routines call formatter or model processor services to retrieve virtual storage data before formatting it.
Field ADPLTCB (also called ADPLCBP) contains the virtual storage dump address of the TCB being processed. If a block does not reside in virtual storage, this field is zeroed, and the exit routine must use ADPLESYP to find the address of the block in the storage mapped by BLSRESSY. This can only happen in the IPCS environment.
When IPCS is the host, field ADPLESYP is set to address a block of storage described by mapping macro BLSRESSY. That block of storage, in turn, describes the address space, address, and the type of data for which a formatting exit routine is being invoked. This allows the exit routine to pass the data unaltered, to the storage access function of the IPCS symbol service and retrieve an image of the block from the dump.
Note: The block of storage described by mapping macro BLSRESSY can reside in storage whose address is greater than X'FFFFFF'. Formatting exit routines that wish to utilize this support must run in AMODE(31) during that portion of their processing that accesses this parameter.

When SNAP is active, this pointer contains zero upon entry to the post-formatting exit routine.