Saturday, March 16, 2024

Domain Linkage

 Calling into a domain gate is via a macro for the desired gate. The macro set R1 to point to the TPL, set R0 to contain the row and column numbers of the gate in the Domain Gate Table and then call to the module DFHKEDCL to link to the gate. The RPL contains a fixed length header and a variable length parameter list. 

CICS use standard register convention when entering gate. R1 points to the parm list. R4 points to the stack storage of current user (similar to stack frame pointer which point to the base of the current frame). R13 points to top of stack of the current frame. R14 is the return address and R15 is the go to addresss. 

No comments: