need more info on CAA when working on a LE migration prj

Shruthi Raghavan · New User Joined: 17 Jan 2007 Posts: 9 Location: India

I am working on LE migration project and have some issues. Can anybody please help me with the conepts of Common Anchor Area (CAA) and enclave. I need to know more about
- R13 pointing to CAA
- invoke cobol in more than one enclave

I would appreciate any kind of help.
Thanks in advance.
Shruthi

UmeySan · Posted: Fri Jan 19, 2007 4:14 pm

Hi Shruthi Raghavan !

When calling LE/370-conforming routines, register 12 points to the address of the CAA.

When a routine makes a call, registers 0-15 contain the following values:

o R0 is used by COBOL static call.
o R1 is a pointer to parameter list or zero if no parameter list passed.
o R2-R11 is unreferenced by LE/370.
Caller's values are passed transparently.
o R12 is the pointer to the CAA if entry to an external routine.
o R13 is the pointer to caller's DSA.
o R14 is the return address.
o R15 is the address of the called entry point.

Here you could find a nice description of the CAA:

cenmvst.gov.ab.ca/bookmgr-cgi/bookmgr.exe/BOOKS/BOOKREAD.LANGUAGE.CEEM1003.BOOK/1.3.2.7?SHELF=BOOKREAD.PUBLIC.MESSAGE.BKSHELF

More information:
publib.boulder.ibm.com/infocenter/pdthelp/v1r1/index.jsp?topic=/com.ibm.entcobol4.doc/igym1apc.htm

Regards, UmeySan

Shruthi Raghavan · New User Joined: 17 Jan 2007 Posts: 9 Location: India

i know that R12 has to point to CAA. But wat is to be done when R12 is used as base registers in teh program.
could you please tell me wat do u mean by 'if entry to an external routine'

Shruthi Raghavan · New User Joined: 17 Jan 2007 Posts: 9 Location: India

An external routine means a another sub module or does it have any other meaning.