![Elf-layout--en](https://upload.wikimedia.org/wikipedia/commons/7/77/Elf-layout--en.svg)
In
computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It includes the study and experimentation of algorithmic processes, and development of both hardware and software. Computing has scientific, ...
, the Executable and Linkable Format
[Tool Interface Standard (TIS) ]
Portable Formats Specification
Version 1.1'' (October 1993) (ELF, formerly named Extensible Linking Format), is a common standard
file format for
executable files,
object code
In computing, object code or object module is the product of a compiler
In computing, a compiler is a computer program that translates computer code written in one programming language (the ''source'' language) into another language (the ...
,
shared libraries
In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and su ...
, and
core dump
In computing, a core dump, memory dump, crash dump, storage dump, system dump, or ABEND dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has crashed or otherwise termina ...
s. First published in the specification for the
application binary interface
In computer software, an application binary interface (ABI) is an interface between two binary program modules. Often, one of these modules is a library or operating system facility, and the other is a program that is being run by a user.
An ...
(ABI) of the
Unix
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, an ...
operating system version named
System V Release 4 (SVR4), and later in the Tool Interface Standard,
[Tool Interface Standard (TIS) ]
Executable and Linking Format (ELF) Specification
Version 1.2'' (May 1995) it was quickly accepted among different vendors of
Unix
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, an ...
systems. In 1999, it was chosen as the standard binary file format for Unix and
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
systems on
x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was intr ...
processors by the
86open
In computing, the Executable and Linkable FormatTool Interface Standard (TIS) Portable Formats SpecificationVersion 1.1'' (October 1993) (ELF, formerly named Extensible Linking Format), is a common standard file format for executable files, obj ...
project.
By design, the ELF format is flexible, extensible, and
cross-platform
In computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several computing platforms. Some cross-platform software ...
. For instance, it supports different
endiannesses and address sizes so it does not exclude any particular
central processing unit
A central processing unit (CPU), also called a central processor, main processor or just Processor (computing), processor, is the electronic circuitry that executes Instruction (computing), instructions comprising a computer program. The CPU per ...
(CPU) or
instruction set architecture. This has allowed it to be adopted by many different
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...
s on many different hardware
platforms.
File layout
Each ELF file is made up of one ELF header, followed by file data. The data can include:
* Program header table, describing zero or more
memory segments
* Section header table, describing zero or more sections
* Data referred to by entries in the program header table or section header table
![ELF Executable and Linkable Format diagram by Ange Albertini](https://upload.wikimedia.org/wikipedia/commons/e/e4/ELF_Executable_and_Linkable_Format_diagram_by_Ange_Albertini.png)
The segments contain information that is needed for
run time
Run(s) or RUN may refer to:
Places
* Run (island), one of the Banda Islands in Indonesia
* Run (stream), a stream in the Dutch province of North Brabant
People
* Run (rapper), Joseph Simmons, now known as "Reverend Run", from the hip-hop group ...
execution of the file, while sections contain important data for linking and relocation. Any
byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
in the entire file can be owned by one section at most, and orphan bytes can occur which are unowned by any section.
File header
The ELF header defines whether to use
32-bit or
64-bit
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit CPUs and ALUs are those that are based on processor registers, address buses, or data buses of that size. A compu ...
addresses. The header contains three fields that are affected by this setting and offset other fields that follow them. The ELF header is 52 or 64 bytes long for 32-bit and 64-bit binaries respectively.
Program header
The program header table tells the system how to create a process image. It is found at file offset , and consists of entries, each with size . The layout is slightly different in
32-bit ELF vs
64-bit
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit CPUs and ALUs are those that are based on processor registers, address buses, or data buses of that size. A compu ...
ELF, because the are in a different structure location for alignment reasons. Each entry is structured as:
Section header
Tools
*
readelf
readelf is a program for displaying various information about object files on Unix-like systems such as objdump. It is part of the GNU binutils.
readelf and objdump
objdump has a similar function but with different features like disassembling. ...
is a Unix binary utility that displays information about one or more ELF files. A
free software
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...
implementation is provided by
GNU Binutils
The GNU Binary Utilities, or , are a set of programming tools for creating and managing binary programs, object files, libraries, profile data, and assembly source code.
Tools
They were originally written by programmers at Cygnus Solutions.
...
.
*
elfutils
provides alternative tools to
GNU Binutils
The GNU Binary Utilities, or , are a set of programming tools for creating and managing binary programs, object files, libraries, profile data, and assembly source code.
Tools
They were originally written by programmers at Cygnus Solutions.
...
purely for Linux.
*
elfdump
is a command for viewing ELF information in an ELF file, available under Solaris and
FreeBSD.
*
objdump
objdump is a command-line program for displaying various information about object files on Unix-like operating systems. For instance, it can be used as a disassembler to view an executable in assembly form. It is part of the GNU Binutils for fine ...
provides a wide range of information about ELF files and other object formats.
objdump
uses the
Binary File Descriptor library
The Binary File Descriptor library (BFD) is the GNU Project's main mechanism for the portable manipulation of object files in a variety of formats. , it supports approximately 50 file formats for some 25 instruction set architectures.
History
...
as a back-end to structure the ELF data.
* The Unix
file
File or filing may refer to:
Mechanical tools and processes
* File (tool), a tool used to ''remove'' fine amounts of material from a workpiece
**Filing (metalworking), a material removal process in manufacturing
** Nail file, a tool used to gent ...
utility can display some information about ELF files, including the
instruction set architecture for which the code in a relocatable, executable, or shared object file is intended, or on which an ELF
core dump
In computing, a core dump, memory dump, crash dump, storage dump, system dump, or ABEND dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has crashed or otherwise termina ...
was produced.
Applications
Unix-like systems
The ELF format has replaced older executable formats in various environments.
It has replaced
a.out and
COFF
The Common Object File Format (COFF) is a format for executable, object code, and shared library computer files used on Unix systems. It was introduced in Unix System V, replaced the previously used a.out format, and formed the basis for ex ...
formats in
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
operating systems:
*
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
*
Solaris /
Illumos
Illumos (stylized as illumos) is a partly free and open-source Unix operating system. It is based on OpenSolaris, which was based on System V Release 4 (SVR4) and the Berkeley Software Distribution (BSD). Illumos comprises a kernel, device d ...
*
IRIX
*
FreeBSD
*
NetBSD
*
OpenBSD
*
Redox
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a ...
*
DragonFly BSD
DragonFly BSD is a free and open-source Unix-like operating system forked from FreeBSD 4.8. Matthew Dillon, an Amiga developer in the late 1980s and early 1990s and FreeBSD developer between 1994 and 2003, began working on DragonFly BSD in ...
*
Syllable
*
HP-UX (except for 32-bit PA-RISC programs which continue to use
SOM)
*
QNX
QNX ( or ) is a commercial Unix-like real-time operating system, aimed primarily at the embedded systems market. QNX was one of the first commercially successful microkernel operating systems.
The product was originally developed in the early ...
Neutrino
*
MINIX
Non-Unix adoption
ELF has also seen some adoption in non-Unix operating systems, such as:
*
OpenVMS, in its
Itanium
Itanium ( ) is a discontinued family of 64-bit Intel microprocessors that implement the Intel Itanium architecture (formerly called IA-64). Launched in June 2001, Intel marketed the processors for enterprise servers and high-performance comput ...
and
amd64
x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit version of the x86 instruction set, first released in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging m ...
versions
*
BeOS Revision 4 and later for
x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was intr ...
based computers (where it replaced the
Portable Executable
The Portable Executable (PE) format is a file format for executables, object code, DLLs and others used in 32-bit and 64-bit versions of Windows operating systems. The PE format is a data structure that encapsulates the information necessary fo ...
format; the
PowerPC version stayed with
Preferred Executable Format
The Preferred Executable Format is a file format that specifies the format of executable files and other object code. PEF executables are also called Code Fragment Manager files (CFM).
PEF was developed by Apple Computer for use in its classic Ma ...
)
*
Haiku
is a type of short form poetry originally from Japan. Traditional Japanese haiku consist of three phrases that contain a ''kireji'', or "cutting word", 17 '' on'' (phonetic units similar to syllables) in a 5, 7, 5 pattern, and a ''kigo'', or s ...
, an open source reimplementation of BeOS
*
RISC OS
RISC OS is a computer operating system originally designed by Acorn Computers Ltd in Cambridge, England. First released in 1987, it was designed to run on the ARM chipset, which Acorn had designed concurrently for use in its new line of Archi ...
*
Stratus VOS
Stratus VOS (Virtual Operating System) is a proprietary operating system running on Stratus Technologies fault-tolerant computer systems. VOS is available on Stratus's ftServer and Continuum platforms. VOS customers use it to support high-volume ...
, in PA-RISC and x86 versions
*
SkyOS
SkyOS (''Sky Operating System'') is a discontinued prototype commercial, proprietary, graphical desktop operating system written for the x86 computer architecture. As of January 30, 2009 development was halted with no plans to resume its develop ...
*
Fuchsia OS
*
Z/TPF
*
HPE NonStop OS
*
Deos
DDC-I, Inc. is a privately held company providing software development of real-time operating systems, software development tools, and software services for safety-critical embedded applications, headquartered in Phoenix, Arizona. It was first cr ...
Microsoft Windows also uses the ELF format, but only for its
Windows Subsystem for Linux
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ser ...
compatibility system.
Game consoles
Some game consoles also use ELF:
*
PlayStation Portable,
PlayStation Vita,
PlayStation (console)
The (abbreviated as PS, commonly known as the PS1/PS one or its codename PSX) is a home video game console developed and marketed by Sony Computer Entertainment. It was released in Japan on 3 December 1994, in North America on 9 September 1995 ...
,
PlayStation 2,
PlayStation 3
The PlayStation 3 (PS3) is a home video game console developed by Sony Computer Entertainment. The successor to the PlayStation 2, it is part of the PlayStation brand of consoles. It was first released on November 11, 2006, in Japan, November ...
,
PlayStation 4,
PlayStation 5
*
GP2X
The GP2X is a Linux-based handheld video game console and portable media player developed by South Korean company GamePark Holdings. It was released on November 10, 2005, in South Korea only.
The GP2X is designed for homebrew developers as wel ...
*
Dreamcast
The is a home video game console released by Sega on November 27, 1998, in Japan; September 9, 1999, in North America; and October 14, 1999, in Europe. It was the first sixth-generation video game console, preceding Sony's PlayStation 2, Nint ...
*
GameCube
*
Nintendo 64
The (N64) is a home video game console developed by Nintendo. The successor to the Super Nintendo Entertainment System, it was released on June 23, 1996, in Japan, on September 29, 1996, in North America, and on March 1, 1997, in Europe and ...
*
Wii
*
Wii U
The Wii U ( ) is a home video game console developed by Nintendo as the successor to the Wii. Released in late 2012, it is the first eighth-generation video game console and competed with Microsoft's Xbox One and Sony's PlayStation 4.
Th ...
PowerPC
Other (operating) systems running on
PowerPC that use ELF:
*
AmigaOS 4
AmigaOS 4 (abbreviated as OS4 or AOS4) is a line of Amiga operating systems which runs on PowerPC microprocessors. It is mainly based on AmigaOS 3.1 source code developed by Commodore, and partially on version 3.9 developed by Haage & Partne ...
, the ELF executable has replaced the prior
Extended Hunk Format
Hunk is the executable file format of tools and programs of the Amiga Operating System based on Motorola 68000 CPU and other processors of the same family. This kind of executable got its name from the fact that the software programmed on Amiga ...
(EHF) which was used on Amigas equipped with PPC processor expansion cards.
*
MorphOS
MorphOS is an AmigaOS-like computer operating system (OS). It is a mixed proprietary and open source OS produced for the Pegasos PowerPC (PPC) processor based computer, PowerUP accelerator equipped Amiga computers, and a series of Freescale dev ...
*
AROS Aros may refer to:
*Aros (Middle-earth), a river in J. R. R. Tolkien's Middle-earth legendarium
* Aros, Mull, the location of Aros Castle, a ruined 13th-century castle on the Isle of Mull, Scotland
*AROS Research Operating System, a free software i ...
* Café OS (The operating system ran on Wii U)
Mobile phones
Some operating systems for mobile phones and mobile devices use ELF:
*
Symbian OS v9 uses E32Image format that is based on the ELF file format;
*
Sony Ericsson
Sony Mobile Communications Inc. ( ja, ソニーモバイルコミュニケーションズ株式会社) was a multinational telecommunications company founded on October 1, 2001, as a joint venture between Sony Group Corporation and Ericsson. ...
, for example, the
W800i
The W800 Walkman, released in 2005 (1 August 2005 in the UK), was the first Sony Ericsson phone to use the Walkman brand. The phone features Bluetooth v1.2 (with full Bluetooth 2.0 compliance), Infrared and USB connectivity.
Description
The W8 ...
,
W610,
W300, etc.
*
Siemens, the SGOLD and SGOLD2 platforms: from
Siemens C65
The Siemens C65 is a mobile phone announced by Siemens. This phone is under “C-Class” leveling of Siemens for entry levels/ consumer regularly. It was released in March 2004. It weighs 86 g and its dimensions are 100 x 45 x 16 mm ...
to S75 and BenQ-Siemens E71/
EL71;
*
Motorola
Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorol ...
, for example, the E398,
SLVR L7, v360,
v3i (and all phone LTE2 which has the patch applied).
*
Bada
Bada (stylized as bada; Korean: ) is a discontinued mobile operating system developed by Samsung Electronics for devices such as mid- to high-end smartphones and tablet computers. The name is derived from " (bada)", meaning "ocean" or "sea" in ...
, for example, the
Samsung Wave S8500.
*
Nokia
Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational telecommunications, information technology, and consumer electronics corporation, established in 1865. Nokia's main headquarters are in Espoo, Finland, i ...
phones or tablets running the Maemo or the Meego OS, for example, the
Nokia N900
The Nokia N900 is a smartphone made by Nokia. It supersedes the Nokia N810. Its default operating system, Maemo 5, is a Linux-based OS originally developed for the Nokia 770 Internet Tablet. It is the first Nokia device based upon the Texas ...
.
*
Android uses ELF (shared object) libraries for the
Java Native Interface
In software design, the Java Native Interface (JNI) is a foreign function interface programming framework that enables Java code running in a Java virtual machine (JVM) to call and be called by
native applications (programs specific to a hardwa ...
. With
Android Runtime
Android Runtime (ART) is an application runtime environment used by the Android operating system. Replacing Dalvik, the process virtual machine originally used by Android, ART performs the translation of the application's bytecode into native ...
(ART), the default since
Android 5.0 "Lollipop", all applications are compiled into native ELF binaries on installation.
Some phones can run ELF files through the use of a
patch
Patch or Patches may refer to:
Arts, entertainment and media
* Patch Johnson, a fictional character from ''Days of Our Lives''
* Patch (''My Little Pony''), a toy
* "Patches" (Dickey Lee song), 1962
* "Patches" (Chairmen of the Board song) ...
that adds
assembly code
In computer programming, assembly language (or assembler language, or symbolic machine code), often referred to simply as Assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence b ...
to the main
firmware, which is a feature known as ''ELFPack'' in the underground
modding
''Modding'' is a slang expression derived from the English verb " to modify". The term refers to modification of hardware, software, or anything else, to perform a function not originally intended by the designer, or to achieve bespoke specif ...
culture. The ELF file format is also used with the
Atmel AVR (8-bit),
AVR32
and with
Texas Instruments
Texas Instruments Incorporated (TI) is an American technology company headquartered in Dallas, Texas, that designs and manufactures semiconductors and various integrated circuits, which it sells to electronics designers and manufacturers globa ...
MSP430
The MSP430 is a mixed-signal microcontroller family from Texas Instruments, first introduced on 14 February 1992. Built around a CPU, the MSP430 is designed for low cost and, specifically, low power consumption embedded applications.
Applic ...
microcontroller architectures. Some implementations of
Open Firmware
Open Firmware is a standard defining the interfaces of a computer firmware system, formerly endorsed by the Institute of Electrical and Electronics Engineers (IEEE). It originated at Sun Microsystems, where it was known as OpenBoot, and has bee ...
can also load ELF files, most notably
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, where its wild ancestor, ' ...
's implementation used in almost all
PowerPC machines the company produced.
Specifications
* Generic:
**
System V Application Binary Interface' Edition 4.1 (1997-03-18)
**
' (October 2009)
*
AMD64
x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit version of the x86 instruction set, first released in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging m ...
:
**
System V ABI, AMD64 Supplement'
*
Arm
In human anatomy, the arm refers to the upper limb in common usage, although academically the term specifically means the upper arm between the glenohumeral joint (shoulder joint) and the elbow joint. The distal part of the upper limb between th ...
:
**
ELF for the ARM Architecture'
*
IA-32
IA-32 (short for "Intel Architecture, 32-bit", commonly called i386) is the 32-bit version of the x86 instruction set architecture, designed by Intel and first implemented in the 80386 microprocessor in 1985. IA-32 is the first incarnation o ...
:
**
System V ABI, Intel386 Architecture Processor Supplement'
*
IA-64
IA-64 (Intel Itanium architecture) is the instruction set architecture (ISA) of the Itanium family of 64-bit Intel microprocessors. The basic ISA specification originated at Hewlett-Packard (HP), and was subsequently implemented by Intel in col ...
:
**
Itanium Software Conventions and Runtime Guide' (September 2000)
*
M32R
The M32R is a 32-bit RISC instruction set architecture (ISA) developed by Mitsubishi Electric for embedded microprocessors and microcontrollers. The ISA is now owned by Renesas Electronics Corporation, and the company designs and fabricates M32R im ...
:
**
M32R ELF ABI Supplement' Version 1.2 (2004-08-26)
*
MIPS:
**
System V ABI, MIPS RISC Processor Supplement'
**
' (2003-06-11)
*
Motorola 6800
The 6800 ("''sixty-eight hundred''") is an 8-bit microprocessor designed and first manufactured by Motorola in 1974. The MC6800 microprocessor was part of the M6800 Microcomputer System (latter dubbed ''68xx'') that also included serial and para ...
:
**
Motorola 8- and 16- bit Embedded ABI'
*
PA-RISC
PA-RISC is an instruction set architecture (ISA) developed by Hewlett-Packard. As the name implies, it is a reduced instruction set computer (RISC) architecture, where the PA stands for Precision Architecture. The design is also referred to as ...
:
**
ELF Supplement for PA-RISC' Version 1.43 (October 6, 1997)
*
PowerPC:
**
System V ABI, PPC Supplement'
**
PowerPC Embedded Application Binary Interface32-Bit Implementation'' (1995-10-01)
**
' Version 1.9 (2004)
*
RISC-V
RISC-V (pronounced "risk-five" where five refers to the number of generations of RISC architecture that were developed at the University of California, Berkeley since 1981) is an open standard instruction set architecture (ISA) based on estab ...
:
**
RISC-V ELF Specification'
*
SPARC
SPARC (Scalable Processor Architecture) is a reduced instruction set computer (RISC) instruction set architecture originally developed by Sun Microsystems. Its design was strongly influenced by the experimental Berkeley RISC system develope ...
:
**
System V ABI, SPARC Supplement'
*
S/390:
**
S/390 32bit ELF ABI Supplement'
*
zSeries
IBM Z is a family name used by IBM for all of its z/Architecture mainframe computers.
In July 2017, with another generation of products, the official family was changed to IBM Z from IBM z Systems; the IBM Z family now includes the newest mod ...
:
**
zSeries 64bit ELF ABI Supplement'
*
Symbian OS 9:
**
E32Image file format on Symbian OS 9'
The
Linux Standard Base
The Linux Standard Base (LSB) was a joint project by several Linux distributions under the organizational structure of the Linux Foundation to standardize the software system structure, including the Filesystem Hierarchy Standard used in the ...
(LSB) supplements some of the above specifications for architectures in which it is specified. For example, that is the case for the System V ABI, AMD64 Supplement.
86open
86open was a project to form consensus on a common
binary file
A binary file is a computer file that is not a text file. The term "binary file" is often used as a term meaning "non-text file". Many binary file formats contain parts that can be interpreted as text; for example, some computer document fil ...
format for
Unix
Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, an ...
and
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs.
Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...
s on the common
PC compatible
IBM PC compatible computers are similar to the original IBM PC, XT, and AT, all from computer giant IBM, that are able to use the same software and expansion cards. Such computers were referred to as PC clones, IBM clones or IBM PC clones. ...
x86
x86 (also known as 80x86 or the 8086 family) is a family of complex instruction set computer (CISC) instruction set architectures initially developed by Intel based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was intr ...
architecture, to encourage software developers to port to the architecture. The initial idea was to standardize on a small subset of Spec 1170, a predecessor of the
Single UNIX Specification, and the GNU C Library (glibc) to enable unmodified binaries to run on the x86 Unix-like operating systems. The project was originally designated "Spec 150".
The format eventually chosen was ELF, specifically the Linux implementation of ELF, after it had turned out to be a
''de facto'' standard supported by all involved vendors and operating systems.
The group began email discussions in 1997 and first met together at the
Santa Cruz Operation
The Santa Cruz Operation, Inc. (usually known as SCO, pronounced either as individual letters or as a word) was an American software company, based in Santa Cruz, California, that was best known for selling three Unix operating system variants ...
offices on August 22, 1997.
The steering committee was
Marc Ewing
Marc Ewing is an American computer engineer and entrepreneur. He is the creator and originator of the Red Hat brand of software, most notably the Red Hat range of Linux operating system distributions. He was involved in the 86open project in t ...
, Dion Johnson, Evan Leibovitch,
Bruce Perens
Bruce Perens (born around 1958) is an American computer programmer and advocate in the free software movement. He created The Open Source Definition and published the first formal announcement and manifesto of open source. He co-founded the Open ...
, Andrew Roach,
Bryan Wayne Sparks
Caldera was a US-based software company founded in 1994 to develop Linux- and DOS-based operating system products.
Caldera
Caldera, Inc. was a Canopy-funded software company founded in October 1994 and incorporated on 25 January 1995 by f ...
and
Linus Torvalds
Linus Benedict Torvalds ( , ; born 28 December 1969) is a Finnish software engineer who is the creator and, historically, the lead developer of the Linux kernel, used by Linux distributions and other operating systems such as Android. He also ...
. Other people on the project were
Keith Bostic, Chuck Cranor, Michael Davidson, Chris G. Demetriou, Ulrich Drepper, Don Dugger, Steve Ginzburg,
Jon "maddog" Hall
Jon "maddog" Hall (born 7 August 1950) is the board chair for the Linux Professional Institute.
Career
The nickname "maddog" was given to him by his students at Hartford State Technical College, where he was the Department Head of Computer Sc ...
, Ron Holt,
Jordan Hubbard
Jordan K. Hubbard (born April 8, 1963) is an open source software developer, authoring software such as the Ardent Window Manager and various other open source tools and libraries before co-founding the FreeBSD project with Nate Williams and Rodn ...
, Dave Jensen, Kean Johnston, Andrew Josey, Robert Lipe, Bela Lubkin, Tim Marsland, Greg Page, Ronald Joe Record, Tim Ruckle, Joel Silverstein, Chia-pi Tien, and Erik Troan. Operating systems and companies represented were
BeOS,
BSDI,
FreeBSD,
Intel
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...
,
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
,
NetBSD,
SCO and
SunSoft
, stylized as SUNSOFT, is a Japanese video game developer and publisher.
Sunsoft is the video games division of Japanese electronics manufacturer Sun Corporation. Its U.S. subsidiary operated under the name Sun Corporation of America, though, a ...
.
The project progressed and in mid-1998, SCO began developing
lxrun, an open-source
compatibility layer
In software engineering, a compatibility layer is an interface that allows binaries for a legacy or foreign system to run on a host system. This translates system calls for the foreign system into native system calls for the host system. With so ...
able to run Linux binaries on
OpenServer
Xinuos OpenServer, previously SCO UNIX and SCO Open Desktop (SCO ODT), is a closed source computer operating system developed by Santa Cruz Operation (SCO), later acquired by SCO Group, and now owned by Xinuos. Early versions of OpenServer wer ...
,
UnixWare, and
Solaris. SCO announced official support of lxrun at
LinuxWorld LinuxWorld has various meanings:
* LinuxWorld Conference and Expo - a series of Linux conferences worldwide that became OpenSource World in 2009
* LinuxWorld Magazine - a print publication produced from 2003 to 2006
* LinuxWorld.com
Internation ...
in March 1999.
Sun Microsystems began officially supporting lxrun for Solaris in early 1999, and later moved to integrated support of the Linux binary format via
Solaris Containers for Linux Applications
Solaris Containers (including Solaris Zones) is an implementation of operating system-level virtualization technology for x86 and SPARC systems, first released publicly in February 2004 in build 51 beta of Solaris 10, and subsequently in the fi ...
.
With the BSDs having long supported Linux binaries (through a
compatibility layer
In software engineering, a compatibility layer is an interface that allows binaries for a legacy or foreign system to run on a host system. This translates system calls for the foreign system into native system calls for the host system. With so ...
) and the main x86 Unix vendors having added support for the format, the project decided that Linux ELF was the format chosen by the industry and "declare
itself dissolved" on July 25, 1999.
FatELF: universal binaries for Linux
FatELF is an ELF binary-format extension that adds
fat binary
A fat binary (or multiarchitecture binary) is a computer executable program or library which has been expanded (or "fattened") with code native to multiple instruction sets which can consequently be run on multiple processor types. This results ...
capabilities.
It is aimed for
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
and other
Unix-like
A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...
operating systems. Additionally to the CPU architecture abstraction (
byte order
In computing, endianness, also known as byte sex, is the order or sequence of bytes of a word of digital data in computer memory. Endianness is primarily expressed as big-endian (BE) or little-endian (LE). A big-endian system stores the most sig ...
,
word size
In computing, a word is the natural unit of data used by a particular processor design. A word is a fixed-sized datum handled as a unit by the instruction set or the hardware of the processor. The number of bits or digits in a word (the ''word s ...
,
CPU instruction set etc.), there is the potential advantage of software-platform abstraction e.g., binaries which support multiple kernel
ABI versions. , FatELF has not been integrated into the mainline Linux kernel.
See also
*
Application binary interface
In computer software, an application binary interface (ABI) is an interface between two binary program modules. Often, one of these modules is a library or operating system facility, and the other is a program that is being run by a user.
An ...
*
Comparison of executable file formats
This is a comparison of binary executable file formats which, once loaded by a suitable executable loader, can be directly executed by the CPU rather than being interpreted by software. In addition to the binary application code, the executables ma ...
*
DWARF
Dwarf or dwarves may refer to:
Common uses
*Dwarf (folklore), a being from Germanic mythology and folklore
* Dwarf, a person or animal with dwarfism
Arts, entertainment, and media Fictional entities
* Dwarf (''Dungeons & Dragons''), a humanoid ...
a format for debugging data
*
Intel Binary Compatibility Standard The Intel Binary Compatibility Standard (iBCS) is a standardized application binary interface (ABI) for Unix operating systems on Intel-386-compatible computers, published by AT&T, Intel and SCO in 1988, and updated in 1990. It extends source-leve ...
*
Portable Executable
The Portable Executable (PE) format is a file format for executables, object code, DLLs and others used in 32-bit and 64-bit versions of Windows operating systems. The PE format is a data structure that encapsulates the information necessary fo ...
format used by Windows
*
vDSO
vDSO (virtual dynamic shared object) is a kernel mechanism for exporting a carefully selected set of kernel space routines to user space applications so that applications can call these kernel space routines in-process, without incurring the pe ...
virtual DSO
*
Position-independent code
In computing, position-independent code (PIC) or position-independent executable (PIE) is a body of machine code that, being placed somewhere in the primary memory, executes properly regardless of its absolute address. PIC is commonly used fo ...
References
Further reading
* Code
ftp://ftp.iecc.com/pub/linker/] Errata
https://archive.today/20200114224817/https://linker.iecc.com/ 2020-01-14 -->*
*
An unsung hero: The hardworking ELF' by Peter Seebach, December 20, 2005, archived from the original on February 24, 2007
*
*
The ELF Object File Format: Introduction',
The ELF Object File Format by Dissection' by Eric Youngdale (1995-05-01)
*
' by Brian Raiter
by Julien Vanegue (2003-08-13)
by the ELFsh team (2005-08-01)
*
' by Pat Beirne (1999-08-03)
External links
(archived version)
FreeBSD manual pageOracle Solaris Linker and Libraries GuideThe ERESI project : reverse engineering on ELF-based operating systems
Linux Today article on 86openJuly 26, 1999
October 10, 1997,
Bruce Perens
Bruce Perens (born around 1958) is an American computer programmer and advocate in the free software movement. He created The Open Source Definition and published the first formal announcement and manifesto of open source. He co-founded the Open ...
Declaration of Ulrich Drepper (PDF)in
The SCO Group
The SCO Group (often referred to SCO and later called The TSG Group) was an American software company in existence from 2002 to 2012 that became known for owning Unix operating system assets that had belonged to the Santa Cruz Operation (the o ...
vs
IBM, September 19, 2006
86open and ELF discussion on
Groklaw
''Groklaw'' is a website that covered legal news of interest to the free and open source software community. Started as a law blog on May 16, 2003 by paralegal Pamela Jones (''"PJ"''), it covered issues such as the SCO-Linux lawsuits, the EU ...
, August 13, 2006
{{Executables
Executable file formats