RTEMS 4.0.0 On-Line Library

Calling Conventions Introduction

RTEMS Hewlett Packard PA-RISC Applications Supplement

2.1: Introduction

Each high-level language compiler generates subroutine entry and exit code based upon a set of rules known as the compiler's calling convention. These rules address the following issues:

register preservation and usage
parameter passing
call and return mechanism

A compiler's calling convention is of importance when interfacing to subroutines written in another language either assembly or high-level. Even when the high-level language and target processor are the same, different compilers may use different calling conventions. As a result, calling conventions are both processor and compiler dependent.

This chapter describes the calling conventions used by the GNU C and standard HP-UX compilers for the PA-RISC architecture.

RTEMS Hewlett Packard PA-RISC Applications Supplement