The EDCXISA entry point is available to the caller of
EDCXSTRX to
determine the stack space overhead for the environment being created.
Add stack space required by the application to the value returned
by this routine to determine the size of the area to be passed as
the second parameter to
EDCXSTRX. If the routine is called
from assembler, the value should be expected in Register 15. The routine
should be declared as:
#pragma linkage(__xisa,OS)
int __xisa(void);