<s>
can4linux	B-Application
is	O
an	O
Open	B-License
Source	I-License
CAN	B-Protocol
Linux-Kernel	B-Operating_System
device	B-Application
driver	I-Application
.	O
</s>
<s>
Development	O
started	O
in	O
the	O
mid-1990s	O
for	O
the	O
Philips	O
82C200	O
CAN	B-Protocol
controller	I-Protocol
stand	O
alone	O
chip	O
on	O
an	O
ISA	B-Architecture
Board	O
AT-CAN-MINI	O
.	O
</s>
<s>
In	O
1995	O
the	O
first	O
version	O
was	O
created	O
to	O
use	O
the	O
CAN	B-Protocol
bus	I-Protocol
with	O
Linux	B-Operating_System
for	O
laboratory	O
automation	O
as	O
a	O
project	O
of	O
the	O
Linux	B-Operating_System
Lab	O
Project	O
at	O
FU	O
Berlin	O
.	O
</s>
<s>
The	O
increasing	O
spread	O
of	O
the	O
CAN	B-Protocol
field	O
bus	O
technology	O
for	O
automation	O
especially	O
in	O
embedded	B-Architecture
devices	I-Architecture
and	O
the	O
growth	O
of	O
Linux	B-Operating_System
in	O
this	O
area	O
leads	O
to	O
a	O
growing	O
importance	O
of	O
device	B-Application
drivers	I-Application
as	O
base	O
for	O
higher	O
layer	O
CAN	B-Protocol
protocols	O
like	O
CANopen	O
,	O
J1939	B-Application
and	O
DeviceNet	O
.	O
</s>
<s>
Besides	O
the	O
NXP	O
SJA1000	O
as	O
successor	O
of	O
the	O
first	O
supported	O
CAN	B-Protocol
controller	O
Philips	O
82C200	O
and	O
the	O
Intel	O
82527	O
,	O
the	O
development	O
for	O
powerful	O
microcontrollers	B-Architecture
with	O
integrated	O
CAN	B-Protocol
controllers	I-Protocol
that	O
are	O
capable	O
to	O
run	O
the	O
Linux	B-Operating_System
Operating	B-General_Concept
system	I-General_Concept
have	O
been	O
intensified	O
since	O
2005	O
.	O
</s>
<s>
As	O
examples	O
for	O
this	O
development	O
serve	O
Freescale	O
's	O
ColdFire	B-Device
processors	O
or	O
ARM	O
models	O
by	O
ATMEL	O
and	O
Freescale	O
but	O
also	O
the	O
stand-alone	O
CAN	B-Protocol
controller	I-Protocol
MCP2515	O
,	O
connected	O
via	O
SPI	B-Architecture
Bus	I-Architecture
.	O
</s>
<s>
A	O
list	O
of	O
supported	O
CAN	B-Protocol
controllers	I-Protocol
is	O
available	O
on	O
the	O
can4linux	B-Application
project	O
site	O
.	O
</s>
<s>
In	O
the	O
latest	O
version	O
there	O
is	O
a	O
virtual	O
CAN	B-Protocol
mode	O
implemented	O
which	O
allows	O
applications	O
to	O
communicate	O
without	O
CAN	B-Protocol
hardware	O
but	O
only	O
by	O
using	O
the	O
device	B-Application
driver	I-Application
software	O
layer	O
.	O
</s>
<s>
This	O
mode	O
already	O
includes	O
support	O
for	O
the	O
new	O
CAN	B-Protocol
frame	O
format	O
called	O
CAN	B-Protocol
FD	O
which	O
allows	O
data	O
frame	O
length	O
up	O
to	O
64	O
byte	O
.	O
</s>
<s>
Application	O
software	O
opens	O
a	O
CAN	B-Protocol
device	O
descriptor	O
and	O
gets	O
back	O
a	O
file	O
descriptor	O
.	O
</s>
<s>
Using	O
this	O
file	O
descriptor	O
standard	O
operating	B-General_Concept
system	I-General_Concept
functions	O
like	O
read( )	O
and	O
write( )	O
are	O
used	O
to	O
exchange	O
CAN	B-Protocol
frames	O
with	O
other	O
CAN	B-Protocol
nodes	O
on	O
a	O
CAN	B-Protocol
bus	I-Protocol
.	O
</s>
<s>
The	O
following	O
code	O
is	O
an	O
example	O
which	O
puts	O
a	O
CAN	B-Protocol
frame	O
on	O
the	O
bus	O
and	O
afterwards	O
waits	O
for	O
a	O
CAN	B-Protocol
frame	O
transmitted	O
by	O
another	O
CAN	B-Protocol
node	O
.	O
</s>
<s>
More	O
examples	O
are	O
available	O
on	O
the	O
can4linux	B-Application
project	O
site	O
.	O
</s>
<s>
can4linux	B-Application
can	B-Protocol
be	O
compiled	O
in	O
a	O
way	O
that	O
allows	O
more	O
than	O
one	O
process	O
to	O
have	O
access	O
to	O
the	O
same	O
CAN	B-Protocol
controller	I-Protocol
hardware	O
for	O
reading	O
and	O
writing	O
frames	O
on	O
the	O
CAN	B-Protocol
bus	I-Protocol
.	O
</s>
<s>
Beside	O
the	O
real	O
application	O
other	O
processes	O
like	O
data	O
loggers	O
or	O
other	O
diagnosis	O
processes	O
can	B-Protocol
access	O
the	O
bus	O
.	O
</s>
