<s>
In	O
Linux	B-Application
,	O
and	O
other	O
Unix-like	O
operating	B-General_Concept
systems	I-General_Concept
,	O
the	O
directory	O
holds	O
files	O
used	O
in	O
booting	B-Operating_System
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
usage	O
is	O
standardized	O
in	O
the	O
Filesystem	B-Application
Hierarchy	I-Application
Standard	I-Application
.	O
</s>
<s>
The	O
contents	O
are	O
mostly	O
Linux	B-Application
kernel	O
files	O
or	O
boot	B-Application
loader	I-Application
files	O
,	O
depending	O
on	O
the	O
boot	B-Application
loader	I-Application
,	O
most	O
commonly	O
(	O
on	O
Linux	B-Application
)	O
LILO	B-Application
or	O
GRUB	B-Application
.	O
</s>
<s>
LILO	B-Application
creates	O
and	O
uses	O
the	O
following	O
files	O
:	O
</s>
<s>
map	O
–	O
a	O
key	O
file	O
,	O
which	O
records	O
where	O
files	O
needed	O
by	O
LILO	B-Application
during	O
boot	B-Operating_System
are	O
stored	O
.	O
</s>
<s>
Following	O
kernel	O
upgrades	O
,	O
this	O
file	O
must	O
be	O
regenerated	O
by	O
running	O
the	O
"	O
map	O
installer	O
"	O
,	O
which	O
is	O
otherwise	O
the	O
system	O
will	O
not	O
boot	B-Operating_System
.	O
</s>
<s>
boot.xxyy	O
–	O
these	O
512-byte	O
files	O
are	O
backups	O
of	O
boot	B-Device
sectors	I-Device
,	O
either	O
the	O
master	B-Device
boot	I-Device
record	I-Device
(	O
MBR	O
)	O
or	O
volume	B-Device
boot	I-Device
record	I-Device
(	O
VBR	O
)	O
,	O
created	O
when	O
LILO	B-Application
overwrites	O
a	O
boot	B-Device
sector	I-Device
.	O
</s>
<s>
xx	O
and	O
yy	O
are	O
the	O
major	O
and	O
minor	O
device	O
numbers	O
in	O
hex	O
;	O
for	O
example	O
,	O
the	O
drive	O
has	O
numbers	O
8	O
,	O
0	O
,	O
hence	O
its	O
MBR	O
is	O
backed	O
up	O
to	O
while	O
the	O
partition	B-Application
has	O
numbers	O
8	O
,	O
3	O
,	O
hence	O
its	O
VBR	O
is	O
backed	O
up	O
to	O
.	O
</s>
<s>
LILO	B-Application
may	O
also	O
use	O
other	O
files	O
,	O
such	O
as	O
and	O
also	O
stores	O
a	O
non-boot	O
configuration	O
file	O
in	O
.	O
</s>
<s>
GRUB	B-Application
stores	O
its	O
files	O
in	O
the	O
subdirectory	O
(	O
i.e.	O
</s>
<s>
is	O
often	O
simply	O
a	O
directory	O
on	O
the	O
main	O
(	O
or	O
only	O
)	O
hard	O
drive	B-Application
partition	I-Application
.	O
</s>
<s>
However	O
,	O
it	O
may	O
be	O
a	O
separate	O
partition	B-Application
.	O
</s>
<s>
A	O
separate	O
partition	B-Application
is	O
generally	O
only	O
used	O
when	O
bootloaders	B-Application
are	O
incapable	O
of	O
reading	O
the	O
main	O
filesystem	O
(	O
e.g.	O
</s>
<s>
LILO	B-Application
does	O
not	O
recognize	O
XFS	B-Application
)	O
or	O
other	O
problems	O
not	O
easily	O
resolvable	O
by	O
users	O
.	O
</s>
<s>
On	O
UEFI	B-Architecture
systems	O
,	O
including	O
most	O
modern	O
PCs	O
,	O
the	O
EFI	B-Device
system	I-Device
partition	I-Device
is	O
often	O
mounted	O
at	O
or	O
.	O
</s>
