NonStop S-Series Server Description Manual (G06.24+)

HP NonStop S-Series Server Description Manual—520331-003
6-1
6 TNS Execution Modes
The following topics describe operations for the TNS compatibility modes.
Execution Modes for TNS Compatibility
TNS Addressing Conventions
The Environment Register
The Register Stack
Register Stack Operations
The Register Stack in Memory
Basic P Register Operations
Branching, Direct and Indirect
Indexed Addressing in a Code Segment
Direct and Indirect Addressing in the Data Segment
Byte Addressing in the Data Segment
Indexing in the Data Segment
Examples of Indexing in the Data Segment
SG Addressing Mode
Basic Characteristics of Procedures
Procedure Attributes
Defining the Procedure’s Data
Data Segment Addressing Modes
Operations at the Procedure’s Top-of-Stack
Overview of Procedure Call and Exit
Actions of the PCAL Instruction
Actions of the EXIT Instruction
A Procedure’s Local Variables
Passing Parameters to a Called Procedure
Accessing Parameters in the Called Procedure
Saving the Stack Frame on a Call
Restoring a Stack Frame on Return From a Call
Multiple Markers for Nested Calls
Returning a Value to the Caller
Retrieving a Returned Value
Subprocedure Calls
Calling External Procedures
Example of an External Procedure Call
Resolving Virtual Addresses for External Calls
An Accelerated Program File in Virtual Memory
Execution Mode Switches
Procedure Return in Accelerated Code
Mapping Return Addresses and Debug Points
Gateway Tables
Far Jump Tables
Maintaining TNS State Values
Invoking Privilege for CALLABLE Procedures