This specification defines the OpenPOWER ELF V2 application binary interface (ABI). This ABI is derived from and represents the first major update to the Power ABI since the original release of the IBM® RS/6000® ABI. It was developed to make extensive use of new functions available in OpenPOWER-compliant processors. It expects an OpenPOWER-compliant processor to implement at least Power ISA V2.07B with all OpenPOWER Architecture instruction categories as well as OpenPOWER-defined implementation characteristics for some implementation-specific features. Specifically, to use this ABI and ABI-compliant programs, OpenPOWER-compliant processors must implement the following categories: Base 64-Bit Server (subject to system-level requirements) Floating-Point Floating-Point.Record Load/Store Quadword x2 Store Conditional Page Mobility (subject to system-level requirements) Stream Transactional Memory Vector Vector.Little-Endian Vector-Scalar For more information about these categories, see “Categories” in Book I of Power ISA, version 2.07B. The OpenPOWER ELF V2 ABI is intended for use in little- and big-endian environments.

This document is based on the following publications: Power Architecture 32-bit Application Binary Interface Supplement 1.0 by Ryan S. Arnold, Greg Davis, Brian Deitrich, Michael Eager, Emil Medve, Steven J. Munroe, Joseph S. Myers, Steve Papacharalambous, Anmol P. Paralkar, Katherine Stewart, and Edmar Wienskoski, 1.0 Edition. Published April 19, 2011. Copyright © 1999, 2003, 2004 IBM Corporation. Copyright © 2002 Freescale Semiconductor, Inc. Copyright © 2003, 2004 Free Standards Group. Copyright © 2011 Power.org Portions of Power Architecture 32-bit Application Binary Interface Supplement 1.0 are derived from the 64-bit PowerPC® ELF Application Binary Interface Supplement 1.8, originally written by Ian Lance Taylor under contract for IBM, with later revisions by: David Edelsohn, Torbjorn Granlund, Mark Mendell, Kristin Thomas, Alan Modra, Steve Munroe, and Chris Lorenze. The Thread Local Storage section of this document is an original contribution of IBM written by Alan Modra and Steven Munroe. IBM, the IBM logo, and ibm.com are trademarks or registered trademarks of International Business Machines Corp., registered in many jurisdictions worldwide. Other product and service names might be trademarks of IBM or other companies. A current list of IBM trademarks is available on the Web at “Copyright and trademark information” at www.ibm.com/legal/copytrade.shtml. The following terms are trademarks or registered trademarks licensed by Power.org in the United States and/or other countries: Power ISATM, Power Architecture®. Information on the list of U.S. trademarks licensed by Power.org may be found at www.power.org/about/brand-center/. The following terms are trademarks or registered trademarks of Freescale Semiconductor in the United States and/or other countries: AltiVecTM, e500TM. Information on the list of U.S. trademarks owned by Freescale Semiconductor may be found at www.freescale.com/files/abstract/help_page/TERMSOFUSE.html. Itanium, Intel logo, Intel Inside logo, and Intel Centrino logo are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries. Linux is a trademark of Linus Torvalds in the United States, other countries, or both. Java, and all Java-based trademarks and logos are trademarks or registered trademarks of Oracle and/or its affiliates. Other company, product, and service names may be trademarks or service marks of others.