<s>
Process	B-Application
Control	I-Application
Daemon	I-Application
(	O
PCD	O
)	O
is	O
an	O
open	B-License
source	I-License
,	O
light-weight	O
system	O
level	O
process	O
manager/controller	O
for	O
Embedded	B-Application
Linux	I-Application
based	O
projects	O
(	O
such	O
as	O
consumer	O
electronics	O
and	O
network	O
devices	O
)	O
.	O
</s>
<s>
This	O
tool	O
provides	O
a	O
complementary	O
service	O
for	O
any	O
Embedded	B-Application
Linux	I-Application
driven	O
product	O
and	O
is	O
specialized	O
for	O
the	O
needs	O
of	O
embedded	B-Architecture
products	I-Architecture
.	O
</s>
<s>
PCD	O
was	O
created	O
because	O
Embedded	B-Application
Linux	I-Application
distributions	O
did	O
not	O
provide	O
such	O
a	O
tool	O
.	O
</s>
<s>
Other	O
similar	O
tools	O
which	O
are	O
available	O
are	O
not	O
suited	O
for	O
embedded	B-Architecture
products	I-Architecture
in	O
terms	O
of	O
compatibility	O
,	O
performance	O
and	O
limited	O
hardware	O
resources	O
.	O
</s>
<s>
The	O
system	O
was	O
originally	O
started	O
with	O
shell	B-Operating_System
scripts	I-Operating_System
,	O
where	O
the	O
init	B-Device
process	I-Device
started	O
the	O
rcS	O
script	O
,	O
and	O
it	O
started	O
some	O
other	O
scripts	O
.	O
</s>
<s>
Due	O
to	O
the	O
rapid	O
development	O
process	O
of	O
the	O
system	O
's	O
software	O
,	O
more	O
processes	B-Operating_System
and	O
tasks	B-General_Concept
were	O
added	O
,	O
and	O
the	O
scripts	O
became	O
too	O
long	O
,	O
unreadable	O
and	O
hard	O
to	O
maintain	O
.	O
</s>
<s>
There	O
was	O
no	O
efficient	O
way	O
to	O
control	O
the	O
startup	B-Application
process	I-Application
of	O
the	O
system	O
.	O
</s>
<s>
For	O
example	O
,	O
a	O
daemon	B-Operating_System
which	O
listens	O
on	O
a	O
socket	B-Protocol
must	O
precede	O
any	O
clients	O
that	O
send	O
data	O
on	O
this	O
socket	B-Protocol
.	O
</s>
<s>
With	O
shell	B-Operating_System
scripts	I-Operating_System
,	O
there	O
is	O
no	O
efficient	O
way	O
to	O
verify	O
this	O
condition	O
.	O
</s>
<s>
There	O
was	O
no	O
entity	O
that	O
monitored	O
and	O
controlled	O
the	O
processes	B-Operating_System
in	O
the	O
system	O
.	O
</s>
<s>
In	O
case	O
of	O
a	O
process	O
crash	O
,	O
there	O
was	O
no	O
debug	O
information	O
available	O
,	O
unless	O
compiling	O
a	O
special	O
version	O
that	O
supports	O
low	O
optimizations	O
,	O
debug	O
symbols	O
and	O
a	O
GDB	B-Application
server	I-Application
.	O
</s>
<s>
The	O
Debugging	O
and	O
remote	O
debugging	O
capabilities	O
were	O
also	O
improved	O
due	O
to	O
the	O
extended	O
debug	O
information	O
which	O
was	O
available	O
in	O
case	O
of	O
a	O
crash	O
(	O
Segmentation	B-Error_Name
fault	I-Error_Name
,	O
bus	B-General_Concept
error	I-General_Concept
,	O
or	O
similar	O
)	O
.	O
</s>
<s>
The	O
project	O
is	O
no	O
longer	O
active	O
but	O
has	O
been	O
extended	O
to	O
support	O
more	O
embedded	B-Architecture
architectures	I-Architecture
and	O
new	O
features	O
.	O
</s>
<s>
Control	O
and	O
monitor	O
all	O
the	O
processes	B-Operating_System
and	O
services	O
in	O
the	O
system	O
.	O
</s>
<s>
Create	O
a	O
graphical	O
representation	O
of	O
the	O
system	O
's	O
processes	B-Operating_System
.	O
</s>
<s>
The	O
PCD	O
needs	O
to	O
be	O
configured	O
with	O
all	O
the	O
processes	B-Operating_System
,	O
daemons	B-Operating_System
and	O
tasks	B-General_Concept
it	O
controls	O
.	O
</s>
<s>
The	O
PCD	O
also	O
implements	O
a	O
crash	O
daemon	B-Operating_System
that	O
constantly	O
monitors	O
the	O
system	O
health	O
,	O
and	O
performs	O
a	O
recovery	O
action	O
in	O
case	O
of	O
a	O
crash	O
.	O
</s>
<s>
The	O
PCD	O
Project	O
is	O
an	O
Open-Source	B-License
project	O
,	O
and	O
it	O
is	O
licensed	O
under	O
the	O
GNU	B-Application
Lesser	I-Application
General	I-Application
Public	I-Application
License	I-Application
version	O
2.1	O
,	O
as	O
published	O
by	O
the	O
Free	O
Software	O
Foundation	O
:	O
</s>
<s>
The	O
LGPL	B-Application
allows	O
linking	O
and	O
mixing	O
proprietary	O
code	O
with	O
PCD	O
safely	O
.	O
</s>
<s>
It	O
provides	O
4	O
major	O
advantages	O
:	O
It	O
simplifies	O
the	O
initialization	O
code	O
,	O
it	O
improves	O
boot	O
time	O
,	O
it	O
reduces	O
debugging	O
effort	O
(	O
providing	O
great	O
crash	O
logs	O
)	O
,	O
and	O
improves	O
the	O
traditional	O
WD	O
implementation	O
(	O
monitoring	O
all	O
processes	B-Operating_System
and	O
act	O
accordingly	O
)	O
.	O
</s>
<s>
"	O
Things	O
are	O
getting	O
a	O
lot	O
easier	O
for	O
software	O
developers	O
who	O
want	O
to	O
use	O
open	B-License
source	I-License
Linux	O
in	O
their	O
real	O
time	O
embedded	O
designs	O
,	O
particularly	O
on	O
the	O
ARM	O
architecture	O
"	O
.	O
</s>
