<s>
In	O
Linux	B-Operating_System
,	O
the	O
file	O
is	O
a	O
symbol	B-Application
table	I-Application
used	O
by	O
the	O
kernel	B-Operating_System
.	O
</s>
<s>
A	O
symbol	B-Application
table	I-Application
is	O
a	O
look-up	O
between	O
symbol	O
names	O
and	O
their	O
addresses	O
in	O
memory	O
.	O
</s>
<s>
The	O
System.map	B-Application
is	O
required	O
when	O
the	O
address	O
of	O
a	O
symbol	O
name	O
,	O
or	O
the	O
symbol	O
name	O
of	O
an	O
address	O
,	O
is	O
needed	O
.	O
</s>
<s>
It	O
is	O
especially	O
useful	O
for	O
debugging	O
kernel	B-Operating_System
panics	I-Operating_System
and	O
kernel	B-Operating_System
oopses	O
.	O
</s>
<s>
The	O
kernel	B-Operating_System
does	O
the	O
address-to-name	O
translation	O
itself	O
when	O
CONFIG_KALLSYMS	O
is	O
enabled	O
so	O
that	O
tools	O
like	O
ksymoops	O
are	O
not	O
required	O
.	O
</s>
<s>
The	O
following	O
is	O
part	O
of	O
a	O
System.map	B-Application
file	O
:	O
</s>
<s>
Because	O
addresses	O
may	O
change	O
from	O
one	O
build	O
to	O
the	O
next	O
,	O
a	O
new	O
System.map	B-Application
is	O
generated	O
for	O
each	O
build	O
of	O
the	O
kernel	B-Operating_System
.	O
</s>
<s>
The	O
nm	B-Application
utility	O
program	O
on	O
Unix	B-Application
systems	I-Application
list	O
the	O
symbols	O
from	O
object	O
files	O
.	O
</s>
<s>
The	O
System.map	B-Application
is	O
directly	O
related	O
to	O
it	O
,	O
in	O
that	O
this	O
file	O
is	O
produced	O
by	O
nm	B-Application
on	O
the	O
whole	O
kernel	B-Operating_System
program	O
just	O
like	O
nm	B-Application
lists	O
the	O
symbols	O
and	O
their	O
types	O
for	O
any	O
small	O
object	O
programs	O
.	O
</s>
<s>
After	O
building	O
the	O
Linux	B-Operating_System
kernel	I-Operating_System
,	O
System.map	B-Application
is	O
located	O
in	O
the	O
root	O
of	O
the	O
source	O
directory	O
.	O
</s>
