What is an ABI?

An Application Binary Interface (ABI) is the interface which an application program gains access to a particular operating system upon which the application has been implemented to execute. Most often the term ABI refers to a UNIX System V ABI which is a specification of common header files, data structures and system interfaces for UNIX and Linux implementations which define binary compatibility for applications between compliant systems.

An ABI for a specific processor architecture consists of two parts:

1. The generic ABI (gABI) which is those parts of the interface which remain constant across all platforms. In the past, this specification was based upon versions of the System V Application Binary Interface originally written from Santa Cruz Organization (SCO). More recently the standard has become included, by normative reference, in the LSB Common 1.1.0 specification from the Linux Standards Body.

2. The processor specific ABI (psABI) which sets out those parts of the interface which are specific to a particular processor as set out in a related Processor Supplement for UNIX System V ABI. For Intel IA32 architectures, the corresponding psABI is set out in the LSB IA32. In addition to the IA32 specification, there is an IA64 version currently in draft.

UniSoft's ABI Verification Test Suite (ABIVTS)

UniSoft has been working with the UNIX System V ABIs since it's original definition in 1989, and over the years and has been involved in a considerable number of UNIX verification test suite developments based on this specification and related revised editions.

Implementation of the initial ABI test suite commenced in 1990, when under contract to UNIX International, UniSoft produced the gABI test software for the First Edition of the gABI.

Following that, under contract to Novell, Inc., the gABI 1.0 test suite and The Open Group's VSX4 were used as a basis for development of UniSoft's ABI Verification Test Suite (ABIVTS) Release 1, which initially tested the Third Edition based ABIs of Intel and MIPS. UniSoft has further enhanced ABIVTS to cover newer Editions of the ABI and additional processors including:

1. Intel - ABIVTS Release 1 for ABI Third Edition and Release 2 for Fourth Edition.

2. MIPS - ABIVTS Release 1.4 for the MIPS Processor ABI Conformance Guide Version 1.2.1.

3. PowerPC - ABIVTS Release 1.0 for the Third Edition PowerPC Processor Supplement.

4. SPARC - Incorporated in the SPARC Compliance Test (SCT) Release 2.1 and 2.3, including the upgrade to the SPARC V9 processor.