Why We Need a New ABI

Why We Need a New ABI

The Application Binary Interface, or ABI, is the set of rules that all binaries must follow in order to run on an SGI system. This includes, for example, object file format, instruction set, data layout, subroutine calling convention, and system call numbers. The ABI is one part of the mechanism that maintains binary compatibility across all SGI platforms.

Until IRIX operating system version 6.1, Silicon Graphics supported two ABIs: a 32-bit ABI and a 64-bit ABI. IRIX 6.1 supports a new ABI, n32.

The following sections outline limitations of the old 32-bit ABI the 64-bit ABI. These issues form the motivation for the new n32 ABI. Specifically, topics covered include:

"Limitations of the 32-bit ABI"
"Limitations of the 64-bit ABI"
"Motivation for the N32 ABI"

Limitations of the 32-bit ABI
Limitations of the 64-bit ABI
Motivation for the N32 ABI