The Executable and Linking Format (ELF) defines a linking interface for executables and shared objects in two parts. The first part is the generic System V ABI (http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/normativerefs.html#NORMATIVEREFSSECT). The second part is a processor-specific supplement. This document, the OpenPOWER ABI for Linux Supplement for the Power Architecture 64-bit ELF V2 ABI, is the OpenPOWER-compliant processor-specific supplement for use with ELF V2 on 64-bit IBM Power Architecture® systems. This is not a complete System V ABI supplement because it does not define any library interfaces. This document establishes both big-endian and little-endian application binary interfaces (see ). OpenPOWER-compliant processors in the 64-bit Power Architecture can execute in either big-endian or little-endian mode. Executables and executable-generated data (in general) that subscribe to either byte ordering are not portable to a system running in the other mode. Note: This ABI specification does not address little-endian byte ordering before Power ISA 2.03. The OpenPOWER ELF V2 ABI is not the same as either the Power Architecture 32-bit ABI supplement or the 64-bit IBM PowerPC® ELF ABI (ELF V1). The Power Architecture 64-bit OpenPOWER ELF V2 ABI supplement is intended to use the same structural layout now followed in practice by other processor-specific ABIs.

The archetypal ELF ABI is described by the System V ABI. Supersessions and addenda that are specific to OpenPOWER ELF V2 Power Architecture (64-bit) processors are described in this document. The following documents are complementary to this document and equally binding: Power Instruction Set Architecture, Versions 2.7 and 3.0, IBM, 2013-2016. http://www.power.org DWARF Debugging Information Format, Version 4, DWARF Debugging Information Format Workgroup, 2010. http://dwarfstd.org/Dwarf4Std.php ISO/IEC 9899:2011: Programming languages—C. http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=57853 Itanium C++ ABI: Exception Handling. Rev 1.22, CodeSourcery, 2001. http://www.codesourcery.com/public/cxx-abi/abi-eh.html ISO/IEC TR 24732:2009 – Programming languages, their environments and system software interfaces – Extension for the programming language C to support decimal floating-point arithmetic, ISO/IEC, January 05, 2009. Available from ISO. http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=45202 ELF Handling for Thread-Local Storage, Version 0.20, Ulrich Drepper, Red Hat Inc., December 21, 2005. http://people.redhat.com/drepper/tls.pdf The following documents are of interest for their historical information but are not normative in any way. 64-bit PowerPC ELF Application Binary Interface Supplement 1.9. http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html IBM PowerOpen™ ABI Application Binary Interface Big-Endian 32-Bit Hardware Implementation. ftp://www.sourceware.org/pub/binutils/ppc-docs/ppc-poweropen/ Power Architecture 32-bit ABI Supplement 1.0 Embedded/Linux/Unified. https://www.power.org/documentation/power-architecture-32-bit-abi-supplement-1-0-embeddedlinuxunified/ ALTIVEC PIM: AltiVec™ Technology Programming Interface Manual, Freescale Semiconductor, 1999. http://www.freescale.com/files/32bit/doc/ref_manual/ALTIVECPIM.pdf ELF Assembly User’s Guide, Fourth edition, IBM, 2000. https://www-03.ibm.com/technologyconnect/tgcm/TGCMFileServlet.wss/assem_um.pdf?id=109917A251EFD64C872569D900656D07&linkid=1h3000&c_t=md515o6ntgh671shz9ioar20oyfp1grs

Errata recorded at https://openpowerfoundation.org/?resource_lib=openpower-elfv2-errata-elfv2-abi-version-1-4 have been incorporated into this document. PowerISA version 3.1 introduces PC-relative instructions for accessing code and data. Thus compilers and assembly programmers that target version 3.1 or later can, if desired, avoid usage of a TOC pointer for such accesses. The ABI has been updated to describe the implications of this new capability. For specifics, see , , , , , and .