Editing Application binary interface (section)

== {{Anchor|EABI}}Embedded ABI ==
An '''embedded ABI''' (EABI), used on an [[embedded operating system]], specifies aspects such as [[file format]]s, data types, register usage, [[stack frame]] organization, and function parameter passing of an [[Embedded system|embedded]] software program.

Each compiler and [[assembly language|assembler]] that supports an EABI creates [[object code]] that is compatible with code generated by other such compilers and assemblers. This allows developers to link libraries generated by one compiler with object code generated by another.

Typically, an EABI is optimized for performance for the limited resources of the target embedded system. Therefore, an EABI may omit abstractions between [[User space and kernel space|kernel and user space]] typically found in [[desktop computer|desktop]] operating systems. For example, [[dynamic linking]] may be avoided to allow smaller executables and faster loading, fixed register usage allows more compact stacks and kernel calls, and running the application in privileged mode allows direct access to custom hardware operation without the indirection of calling a device driver.<ref name="ppc-eabi">{{cite book
 |     title = PowerPC Embedded Application Binary Interface: 32-Bit Implementation
 |      date = 1 October 1995
 |   edition = Version 1.0
 |   chapter = EABI Summary
 |     pages = 28&ndash;30
 | publisher = Freescale Semiconductor, Inc
 |       url = http://www.nxp.com/docs/en/application-note/PPCEABI.pdf
}}</ref>  The choice of EABI can affect performance.<ref>{{cite web
 |title=Debian ARM accelerates via EABI port
 |date=16 October 2016
 |publisher=Linuxdevices.com
 |url=http://linuxdevices.com/news/NS9048137234.html
 |access-date=11 October 2007
 |archive-url=https://web.archive.org/web/20070121183413/http://www.linuxdevices.com/news/NS9048137234.html
 |archive-date=21 January 2007
|url-status=dead
}}</ref><ref>{{cite web
 |author=Andrés Calderón and Nelson Castillo
 |title=Why ARM's EABI matters
 |date=14 March 2007
 |publisher=Linuxdevices.com
 |url=http://linuxdevices.com/articles/AT5920399313.html
 |access-date=11 October 2007
 |archive-url=https://web.archive.org/web/20070331193917/http://www.linuxdevices.com/articles/AT5920399313.html
 |archive-date=31 March 2007
|url-status=dead
}}</ref>

Widely used EABIs include the [[PowerPC]],<ref name="ppc-eabi"/> [[Arm architecture|Arm]],<ref>{{cite web|url=https://developer.arm.com/architectures/system-architectures/software-standards/abi |title=ABI for the Arm Architecture |publisher=Developer.arm.com |access-date=4 February 2020}}</ref> and [[MIPS architecture|MIPS]] EABIs.<ref>{{cite mailing list |url=https://sourceware.org/legacy-ml/binutils/2003-06/msg00436.html |author=Eric Christopher |title=mips eabi documentation |mailing-list=binutils@sources.redhat.com |date=11 June 2003 |access-date=19 June 2020}}</ref> Specific software implementations like the C library may impose additional limitations to form more concrete ABIs; one example is the GNU OABI and EABI for ARM, both of which are subsets of the ARM EABI.<ref>{{cite web |title=ArmEabiPort |url=https://wiki.debian.org/ArmEabiPort |website=Debian Wiki |quote=Strictly speaking, both the old and new ARM ABIs are subsets of the ARM EABI specification, but in everyday usage the term "EABI" is used to mean the new one described here and "OABI" or "old-ABI" to mean the old one.}}</ref>