Executable and Linkable Format

ELF

Filename extension	none, .axf, .bin, .elf, .o, .prx, .puff and .so
Magic number	0x7F 'E' 'L' 'F'
Developed by	Unix System Laboratories
Type of format	Binary, executable, object, shared libraries, core dump
Container for	Many executable binary formats

In computing, the Executable and Linkable Format (ELF, formerly called Extensible Linking Format) is a common standard file format for executables, object code, shared libraries, and core dumps. First published in the System V Release 4 (SVR4) Application Binary Interface (ABI) specification, and later in the Tool Interface Standard, it was quickly accepted among different vendors of Unix systems. In 1999 it was chosen as the standard binary file format for Unix and Unix-like systems on x86 by the 86open project.

ELF is flexible and extensible by design, and it is not bound to any particular processor or architecture. This has allowed it to be adopted by many different operating systems on many different platforms.

Each ELF file is made up of one ELF header, followed by file data. The file data can include:

The segments contain information that is necessary for runtime execution of the file, while sections contain important data for linking and relocation. Any byte in the entire file can be owned by at most one section, and there can be orphan bytes which are not owned by any section.

00000000 7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 |.ELF............|

00000010 02 00 3e 00 01 00 00 00 c5 48 40 00 00 00 00 00 |..>......H@.....|

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