<!-- Copyright (c) 2016 OpenPOWER Foundation Licensed under the GNU Free Documentation License, Version 1.3; with no Invariants Sections, with no Front-Cover Texts, and with no Back-Cover Texts (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.gnu.org/licenses/fdl-1.3.txt --> <chapter xmlns="http://docbook.org/ns/docbook" xmlns:xi="http://www.w3.org/2001/XInclude" xmlns:xl="http://www.w3.org/1999/xlink" version="5.0" xml:lang="en" xml:id="ch_1"> <title>Introduction</title> <para>The Executable and Linking Format (ELF) defines a linking interface for executables and shared objects in two parts.</para> <itemizedlist> <listitem> <para>The first part is the generic System V ABI (<link xl:href="http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/normativerefs.html#NORMATIVEREFSSECT">http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/normativerefs.html#NORMATIVEREFSSECT</link>). </para> </listitem> <listitem> <para>The second part is a processor-specific supplement.</para> </listitem> </itemizedlist> <para>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.</para> <para>This document establishes both big-endian and little-endian application binary interfaces (see <xref linkend="dbdoclet.50655240___RefHeading___Toc377640574" />). 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.</para> <itemizedlist> <listitem> <para>Note: <link xl:href="http://www.power.org/">This ABI specification does not address little-endian byte ordering before Power ISA 2.03.</link> </para> </listitem> </itemizedlist> <para>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).</para> <para>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.</para> <section xml:id="dbdoclet.50655239___RefHeading___Toc377640569"> <title>Reference Documentation</title> <para>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.</para> <para>The following documents are complementary to this document and equally binding:</para> <itemizedlist> <listitem> <para> <emphasis>Power Instruction Set Architecture,</emphasis> Versions <phrase revisionflag="deleted">2.7</phrase> <phrase revisionflag="added">2.07</phrase> and 3.0, IBM, 2013-2016. <emphasis> <link xl:href="http://www.power.org">http://www.power.org </link> </emphasis></para> </listitem> <listitem> <para> <emphasis>DWARF Debugging Information Format,</emphasis> Version 4, DWARF Debugging Information Format Workgroup, 2010. <emphasis> <link xl:href="http://dwarfstd.org/Dwarf4Std.php">http://dwarfstd.org/Dwarf4Std.php</link> </emphasis></para> </listitem> <listitem> <para> <emphasis>ISO/IEC 9899:2011: Programming languages—C</emphasis>. <emphasis> <link xl:href="http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=57853">http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=57853 </link> </emphasis></para> </listitem> <listitem xml:id="dbdoclet.50655239_page12"> <para>Itanium C++ ABI: Exception Handling. Rev 1.22, CodeSourcery, 2001. <emphasis> <link xl:href="http://www.codesourcery.com/public/cxx-abi/abi-eh.html">http://www.codesourcery.com/public/cxx-abi/abi-eh.html </link> </emphasis></para> </listitem> <listitem> <para> <emphasis>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</emphasis>, ISO/IEC, January 05, 2009. Available from ISO. <emphasis> <link xl:href="http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=45202">http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=45202 </link> </emphasis></para> </listitem> <listitem> <para> <emphasis>ELF Handling for Thread-Local Storage</emphasis>, Version 0.20, Ulrich Drepper, Red Hat Inc., December 21, 2005. <emphasis> <link xl:href="http://people.redhat.com/drepper/tls.pdf">http://people.redhat.com/drepper/tls.pdf </link> </emphasis></para> </listitem> </itemizedlist> <para>The following documents are of interest for their historical information but are not normative in any way.</para> <itemizedlist> <listitem> <para> <emphasis>64-bit PowerPC ELF Application Binary Interface Supplement 1.9.</emphasis> <emphasis> <link xl:href="http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html">http://refspecs.linuxfoundation.org/ELF/ppc64/PPC-elf64abi.html </link> </emphasis> </para> </listitem> <listitem> <para> <emphasis>IBM PowerOpen™ ABI Application Binary Interface Big-Endian 32-Bit Hardware Implementation.</emphasis> <emphasis> <link xl:href="ftp://www.sourceware.org/pub/binutils/ppc-docs/ppc-poweropen/"> <citetitle> ftp://www.sourceware.org/pub/binutils/ppc-docs/ppc-poweropen/</citetitle> </link> </emphasis> </para> </listitem> <listitem> <para> <emphasis>Power Architecture 32-bit ABI Supplement 1.0 Embedded/Linux/Unified.</emphasis> <emphasis> <link xl:href="https://www.power.org/documentation/power-architecture-32-bit-abi-supplement-1-0-embeddedlinuxunified/"> <citetitle> https://www.power.org/documentation/power-architecture-32-bit-abi-supplement-1-0-embeddedlinuxunified/</citetitle> </link> </emphasis> </para> </listitem> <listitem> <para> <emphasis>ALTIVEC PIM: AltiVec™ Technology Programming Interface Manual</emphasis>, Freescale Semiconductor, 1999. <emphasis> <link xl:href="http://www.freescale.com/files/32bit/doc/ref_manual/ALTIVECPIM.pdf">http://www.freescale.com/files/32bit/doc/ref_manual/ALTIVECPIM.pdf </link> </emphasis></para> </listitem> <listitem> <para>ELF Assembly User’s Guide, Fourth edition, IBM, 2000. <emphasis> <link xl:href="https://www-03.ibm.com/technologyconnect/tgcm/TGCMFileServlet.wss/assem_um.pdf?id=109917A251EFD64C872569D900656D07&linkid=1h3000&c_t=md515o6ntgh671shz9ioar20oyfp1grs"> <citetitle> https://www-03.ibm.com/technologyconnect/tgcm/TGCMFileServlet.wss/assem_um.pdf?id=109917A251EFD64C872569D900656D07&linkid=1h3000&c_t=md515o6ntgh671shz9ioar20oyfp1grs</citetitle> </link> </emphasis> </para> </listitem> </itemizedlist> </section> <section revisionflag="added"> <title>Changes from Revision 1.4</title> <itemizedlist> <listitem> <para> Errata recorded at <link xl:href="https://openpowerfoundation.org/?resource_lib=openpower-elfv2-errata-elfv2-abi-version-1-4">https://openpowerfoundation.org/?resource_lib=openpower-elfv2-errata-elfv2-abi-version-1-4</link> have been incorporated into this document. </para> </listitem> <listitem> <para> 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 <xref linkend="dbdoclet.50655241_FnLinkage" />, <xref linkend="dbdoclet.50655240___RefHeading___Toc377640591" />, <xref linkend="dbdoclet.50655241_18894" />, <xref linkend="dbdoclet.50655241_LinkerOpts" />, <xref linkend="dbdoclet.50655242_47739" />, and <xref linkend="dbdoclet.50655242_82622" />. </para> </listitem> </itemizedlist> </section> </chapter>