<s>
In	O
computer	B-Application
software	I-Application
,	O
an	O
application	B-Operating_System
binary	I-Operating_System
interface	I-Operating_System
(	O
ABI	O
)	O
is	O
an	O
interface	B-Application
between	O
two	O
binary	O
program	O
modules	O
.	O
</s>
<s>
Often	O
,	O
one	O
of	O
these	O
modules	O
is	O
a	O
library	B-Library
or	O
operating	B-General_Concept
system	I-General_Concept
facility	O
,	O
and	O
the	O
other	O
is	O
a	O
program	O
that	O
is	O
being	O
run	O
by	O
a	O
user	O
.	O
</s>
<s>
An	O
ABI	O
defines	O
how	O
data	O
structures	O
or	O
computational	O
routines	O
are	O
accessed	O
in	O
machine	B-Language
code	I-Language
,	O
which	O
is	O
a	O
low-level	O
,	O
hardware-dependent	O
format	O
.	O
</s>
<s>
In	O
contrast	O
,	O
an	O
API	B-Application
defines	O
this	O
access	O
in	O
source	O
code	O
,	O
which	O
is	O
a	O
relatively	O
high-level	O
,	O
hardware-independent	O
,	O
often	O
human-readable	B-General_Concept
format	I-General_Concept
.	O
</s>
<s>
Examples	O
of	O
this	O
are	O
the	O
x86	B-Architecture
calling	I-Architecture
conventions	I-Architecture
.	O
</s>
<s>
Adhering	O
to	O
an	O
ABI	O
(	O
which	O
may	O
or	O
may	O
not	O
be	O
officially	O
standardized	O
)	O
is	O
usually	O
the	O
job	O
of	O
a	O
compiler	B-Language
,	O
operating	B-General_Concept
system	I-General_Concept
,	O
or	O
library	B-Library
author	O
.	O
</s>
<s>
However	O
,	O
an	O
application	O
programmer	O
may	O
have	O
to	O
deal	O
with	O
an	O
ABI	O
directly	O
when	O
writing	O
a	O
program	O
in	O
a	O
mix	O
of	O
programming	O
languages	O
,	O
or	O
even	O
compiling	B-Language
a	O
program	O
written	O
in	O
the	O
same	O
language	O
with	O
different	O
compilers	B-Language
.	O
</s>
<s>
In	O
the	O
case	O
of	O
a	O
complete	O
operating	B-General_Concept
system	I-General_Concept
ABI	O
,	O
the	O
binary	O
format	O
of	O
object	B-Application
files	I-Application
,	O
program	B-Library
libraries	I-Library
,	O
etc	O
.	O
</s>
<s>
A	O
complete	O
ABI	O
,	O
such	O
as	O
the	O
Intel	B-Operating_System
Binary	I-Operating_System
Compatibility	I-Operating_System
Standard	I-Operating_System
(	O
iBCS	O
)	O
,	O
allows	O
a	O
program	O
from	O
one	O
operating	B-General_Concept
system	I-General_Concept
supporting	O
that	O
ABI	O
to	O
run	O
without	O
modifications	O
on	O
any	O
other	O
such	O
system	O
,	O
provided	O
that	O
necessary	O
shared	O
libraries	O
are	O
present	O
,	O
and	O
similar	O
prerequisites	O
are	O
fulfilled	O
.	O
</s>
<s>
ABIs	O
can	O
also	O
standardize	O
details	O
such	O
as	O
the	O
C++	O
name	O
mangling	O
,	O
exception	B-General_Concept
propagation	O
,	O
and	O
calling	O
convention	O
between	O
compilers	B-Language
on	O
the	O
same	O
platform	O
,	O
but	O
do	O
not	O
require	O
cross-platform	O
compatibility	O
.	O
</s>
<s>
An	O
embedded-application	O
binary	O
interface	O
(	O
EABI	O
)	O
specifies	O
standard	O
conventions	O
for	O
file	O
formats	O
,	O
data	O
types	O
,	O
register	O
usage	O
,	O
stack	O
frame	O
organization	O
,	O
and	O
function	O
parameter	O
passing	O
of	O
an	O
embedded	B-Architecture
software	O
program	O
,	O
for	O
use	O
with	O
an	O
embedded	B-Operating_System
operating	I-Operating_System
system	I-Operating_System
.	O
</s>
<s>
Compilers	B-Language
that	O
support	O
the	O
EABI	O
create	O
object	B-Language
code	I-Language
that	O
is	O
compatible	O
with	O
code	O
generated	O
by	O
other	O
such	O
compilers	B-Language
,	O
allowing	O
developers	O
to	O
link	O
libraries	O
generated	O
with	O
one	O
compiler	B-Language
with	O
object	B-Language
code	I-Language
generated	O
with	O
another	O
compiler	B-Language
.	O
</s>
<s>
Developers	O
writing	O
their	O
own	O
assembly	B-Language
language	I-Language
code	O
may	O
also	O
interface	B-Application
with	O
assembly	O
generated	O
by	O
a	O
compliant	O
compiler	B-Language
.	O
</s>
<s>
EABIs	O
are	O
designed	O
to	O
optimize	O
for	O
performance	O
within	O
the	O
limited	O
resources	O
of	O
an	O
embedded	B-Architecture
system	I-Architecture
.	O
</s>
<s>
Therefore	O
,	O
EABIs	O
omit	O
most	O
abstractions	O
that	O
are	O
made	O
between	O
kernel	B-Operating_System
and	O
user	O
code	O
in	O
complex	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
For	O
example	O
,	O
dynamic	B-Application
linking	I-Application
may	O
be	O
avoided	O
to	O
allow	O
smaller	O
executables	O
and	O
faster	O
loading	O
,	O
fixed	O
register	O
usage	O
allows	O
more	O
compact	O
stacks	O
and	O
kernel	B-Operating_System
calls	O
,	O
and	O
running	O
the	O
application	O
in	O
privileged	O
mode	O
allows	O
direct	O
access	O
to	O
custom	O
hardware	O
operation	O
without	O
the	O
indirection	O
of	O
calling	O
a	O
device	O
driver	O
.	O
</s>
<s>
Widely	O
used	O
EABIs	O
include	O
PowerPC	B-Architecture
,	O
Arm	B-Architecture
EABI	O
and	O
MIPS	B-Device
EABI	O
.	O
</s>
<s>
Specific	O
software	O
implementations	O
like	O
the	O
C	O
library	B-Library
may	O
impose	O
additional	O
limitations	O
to	O
form	O
more	O
concrete	O
ABIs	O
;	O
one	O
example	O
is	O
the	O
GNU	O
OABI	O
and	O
EABI	O
for	O
ARM	B-Architecture
,	O
both	O
of	O
which	O
are	O
subsets	O
of	O
the	O
ARM	B-Architecture
EABI	O
.	O
</s>
