<s>
The	O
Apple	B-Device
–	I-Device
Intel	I-Device
architecture	I-Device
,	O
or	O
Mactel	B-Device
,	O
is	O
an	O
unofficial	O
name	O
used	O
for	O
Macintosh	B-Device
personal	B-Device
computers	I-Device
developed	O
and	O
manufactured	O
by	O
Apple	B-Device
Inc	O
.	O
that	O
use	O
Intel	B-Operating_System
x86	I-Operating_System
processors	O
,	O
rather	O
than	O
the	O
PowerPC	B-Architecture
and	O
Motorola	O
68000	O
(	O
"	O
68k	B-Device
"	O
)	O
series	O
processors	O
used	O
in	O
their	O
predecessors	O
or	O
the	O
ARM-based	B-Architecture
Apple	B-Device
silicon	I-Device
SoCs	B-Architecture
used	O
in	O
their	O
successors	O
.	O
</s>
<s>
With	O
the	O
change	O
in	O
architecture	B-General_Concept
,	O
a	O
change	O
in	O
firmware	B-Application
became	O
necessary	O
;	O
Apple	B-Device
selected	O
the	O
Intel-designed	O
Extensible	B-Architecture
Firmware	I-Architecture
Interface	I-Architecture
(	O
EFI	B-Architecture
)	O
as	O
its	O
comparable	O
component	O
to	O
the	O
Open	B-Architecture
Firmware	I-Architecture
used	O
on	O
its	O
PowerPC	B-Architecture
architectures	O
,	O
and	O
as	O
the	O
firmware-based	O
replacement	O
for	O
the	O
PC	B-Operating_System
BIOS	I-Operating_System
from	O
Intel	O
.	O
</s>
<s>
With	O
the	O
change	O
in	O
processor	O
architecture	B-General_Concept
to	O
x86	B-Operating_System
,	O
Macs	O
gained	O
the	O
ability	O
to	O
boot	O
into	O
x86-native	O
operating	B-General_Concept
systems	I-General_Concept
(	O
such	O
as	O
Microsoft	B-Application
Windows	I-Application
)	O
,	O
while	O
Intel	O
VT-x	O
brought	O
near-native	O
virtualization	O
with	O
macOS	B-Operating_System
as	O
the	O
host	O
OS	O
.	O
</s>
<s>
Apple	B-Device
uses	O
a	O
subset	O
of	O
the	O
standard	O
PC	O
architecture	B-General_Concept
,	O
which	O
provides	O
support	O
for	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
and	O
support	O
for	O
other	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Hardware	O
and	O
firmware	B-Application
components	O
that	O
must	O
be	O
supported	O
to	O
run	O
an	O
operating	B-General_Concept
system	I-General_Concept
on	O
Apple-Intel	B-Device
hardware	O
include	O
the	O
Extensible	B-Architecture
Firmware	I-Architecture
Interface	I-Architecture
.	O
</s>
<s>
With	O
the	O
change	O
in	O
architecture	B-General_Concept
,	O
a	O
change	O
in	O
firmware	B-Application
became	O
necessary	O
.	O
</s>
<s>
Extensible	B-Architecture
Firmware	I-Architecture
Interface	I-Architecture
(	O
EFI	B-Architecture
)	O
is	O
the	O
firmware-based	O
replacement	O
for	O
the	O
PC	B-Operating_System
BIOS	I-Operating_System
from	O
Intel	O
.	O
</s>
<s>
Designed	O
by	O
Intel	O
,	O
it	O
was	O
chosen	O
by	O
Apple	B-Device
to	O
replace	O
Open	B-Architecture
Firmware	I-Architecture
,	O
used	O
on	O
PowerPC	B-Architecture
architectures	O
.	O
</s>
<s>
Since	O
many	O
operating	B-General_Concept
systems	I-General_Concept
,	O
such	O
as	O
Windows	B-Application
XP	I-Application
and	O
many	O
versions	O
of	O
Windows	O
Vista	O
,	O
are	O
incompatible	O
with	O
EFI	B-Architecture
,	O
Apple	B-Device
released	O
a	O
firmware	B-Application
upgrade	O
with	O
a	O
Compatibility	O
Support	O
Module	O
that	O
provides	O
a	O
subset	O
of	O
traditional	O
BIOS	B-Operating_System
support	O
with	O
its	O
Boot	B-Application
Camp	I-Application
product	O
.	O
</s>
<s>
It	O
is	O
a	O
part	O
of	O
the	O
Extensible	B-Architecture
Firmware	I-Architecture
Interface	I-Architecture
(	O
EFI	B-Architecture
)	O
standard	O
proposed	O
by	O
Intel	O
as	O
a	O
substitute	O
for	O
the	O
earlier	O
PC	B-Operating_System
BIOS	I-Operating_System
.	O
</s>
<s>
The	O
GPT	O
replaces	O
the	O
Master	O
Boot	O
Record	O
(	O
MBR	O
)	O
used	O
with	O
BIOS	B-Operating_System
.	O
</s>
<s>
Intel	B-Device
Macs	I-Device
can	O
boot	O
in	O
two	O
ways	O
:	O
directly	O
via	O
EFI	B-Architecture
,	O
or	O
in	O
a	O
"	O
legacy	O
"	O
BIOS	B-Operating_System
compatibility	O
mode	O
.	O
</s>
<s>
For	O
multibooting	B-Operating_System
,	O
holding	O
down	O
"	O
Option	B-Device
"	O
gives	O
a	O
choice	O
of	O
bootable	O
devices	O
,	O
while	O
the	O
rEFInd	B-Device
bootloader	B-Application
is	O
commonly	O
used	O
for	O
added	O
configurability	O
.	O
</s>
<s>
Legacy	O
Live	O
USBs	B-Protocol
cannot	O
be	O
used	O
on	O
Intel	B-Device
Macs	I-Device
;	O
the	O
EFI	B-Architecture
firmware	B-Application
can	O
recognize	O
and	O
boot	O
from	O
USB	B-Protocol
drives	O
,	O
but	O
it	O
can	O
only	O
do	O
this	O
in	O
EFI	B-Architecture
mode	O
–	O
when	O
the	O
firmware	B-Application
switches	O
to	O
BIOS	B-Operating_System
mode	O
,	O
it	O
no	O
longer	O
recognizes	O
USB	B-Protocol
drives	O
,	O
due	O
to	O
lack	O
of	O
a	O
BIOS-mode	O
USB	B-Protocol
driver	O
.	O
</s>
<s>
Many	O
operating	B-General_Concept
systems	I-General_Concept
,	O
such	O
as	O
earlier	O
versions	O
of	O
Windows	O
and	O
Linux	B-Application
,	O
could	O
only	O
be	O
booted	O
in	O
BIOS	B-Operating_System
mode	O
,	O
or	O
were	O
more	O
easily	O
booted	O
or	O
perform	O
better	O
when	O
booted	O
in	O
BIOS	B-Operating_System
mode	O
,	O
and	O
thus	O
USB	B-Protocol
booting	O
on	O
Intel-based	B-Device
Macs	I-Device
was	O
for	O
a	O
time	O
largely	O
limited	O
to	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
,	O
which	O
can	O
easily	O
be	O
booted	O
via	O
EFI	B-Architecture
.	O
</s>
<s>
On	O
April	O
5	O
,	O
2006	O
,	O
Apple	B-Device
made	O
available	O
for	O
download	O
a	O
public	O
beta	O
version	O
of	O
Boot	B-Application
Camp	I-Application
,	O
a	O
collection	O
of	O
technologies	O
that	O
allows	O
users	O
of	O
Intel-based	B-Device
Macs	I-Device
to	O
boot	O
Windows	B-Application
XP	I-Application
Service	O
Pack	O
2	O
.	O
</s>
<s>
The	O
first	O
non-beta	O
version	O
of	O
Boot	B-Application
Camp	I-Application
is	O
included	O
in	O
Mac	B-Application
OS	I-Application
X	I-Application
v10.5	I-Application
,	O
"	O
Leopard.	O
"	O
</s>
<s>
Before	O
the	O
introduction	O
of	O
Boot	B-Application
Camp	I-Application
,	O
which	O
provides	O
most	O
hardware	B-Application
drivers	I-Application
for	O
Windows	B-Application
XP	I-Application
,	O
drivers	B-Application
for	O
XP	B-Application
were	O
difficult	O
to	O
find	O
.	O
</s>
<s>
Linux	B-Application
can	O
also	O
be	O
booted	O
with	O
Boot	B-Application
Camp	I-Application
.	O
</s>
<s>
Intel-based	B-Device
Mac	I-Device
computers	O
use	O
very	O
similar	O
hardware	O
to	O
PCs	B-Device
from	O
other	O
manufacturers	O
that	O
ship	O
with	O
Microsoft	B-Application
Windows	I-Application
or	O
Linux	B-Application
operating	I-Application
systems	I-Application
.	O
</s>
<s>
In	O
particular	O
,	O
CPUs	B-Device
,	O
chipsets	B-Device
,	O
and	O
GPUs	B-Architecture
are	O
entirely	O
compatible	O
.	O
</s>
<s>
However	O
,	O
Apple	B-Device
computers	O
also	O
include	O
some	O
custom	O
hardware	O
and	O
design	O
choices	O
not	O
found	O
in	O
competing	O
systems	O
:	O
</s>
<s>
System	B-Device
Management	I-Device
Controller	I-Device
is	O
a	O
custom	O
Apple	B-Device
chip	O
that	O
controls	O
various	O
functions	O
of	O
the	O
computer	O
related	O
to	O
power	O
management	O
,	O
including	O
handling	O
the	O
power	O
button	O
,	O
management	O
of	O
battery	O
and	O
thermal	O
sensors	O
,	O
among	O
others	O
.	O
</s>
<s>
It	O
also	O
plays	O
a	O
part	O
in	O
the	O
protection	O
scheme	O
deployed	O
to	O
restrict	O
booting	O
macOS	B-Operating_System
to	O
Apple	B-Device
hardware	O
(	O
see	O
Digital	O
Rights	O
Management	O
below	O
)	O
.	O
</s>
<s>
Intel-based	B-Device
Mac	I-Device
does	O
n't	O
implement	O
TPM	O
.	O
</s>
<s>
Early	O
MacBook	B-Device
and	O
MacBook	B-Device
Pro	I-Device
computers	O
used	O
an	O
internal	O
variant	O
of	O
USB	B-Protocol
as	O
a	O
keyboard	B-Device
and	O
trackpad	B-Device
interconnect	O
.	O
</s>
<s>
Since	O
the	O
2013	O
revision	O
of	O
MacBook	B-Device
Air	I-Device
,	O
Apple	B-Device
started	O
to	O
use	O
a	O
custom	O
Serial	B-Architecture
Peripheral	I-Architecture
Interface	I-Architecture
controller	O
instead	O
.	O
</s>
<s>
The	O
2016	O
MacBook	B-Device
Pro	I-Device
additionally	O
uses	O
a	O
custom	O
internal	O
USB	B-Protocol
device	O
dubbed	O
"	O
iBridge	O
"	O
as	O
an	O
interface	O
to	O
the	O
Touch	O
Bar	O
and	O
Touch	O
ID	O
components	O
,	O
as	O
well	O
as	O
the	O
FaceTime	B-Operating_System
Camera	I-Operating_System
.	O
</s>
<s>
PC	O
laptops	O
generally	O
use	O
internal	O
variant	O
of	O
the	O
legacy	O
PS/2	B-Protocol
keyboard	I-Protocol
interconnect	O
.	O
</s>
<s>
PS/2	B-Protocol
also	O
used	O
to	O
be	O
the	O
standard	O
for	O
PC	O
laptop	O
pointing	O
devices	O
,	O
although	O
a	O
variety	O
of	O
other	O
interfaces	O
,	O
including	O
USB	B-Protocol
,	O
SMBus	B-Algorithm
,	O
and	O
I2C	O
,	O
may	O
also	O
be	O
used	O
.	O
</s>
<s>
Additional	O
custom	O
hardware	O
may	O
include	O
a	O
GMUX	O
chip	O
that	O
controls	O
GPU	B-Device
switching	I-Device
,	O
non-compliant	O
implementations	O
of	O
solid-state	B-Device
storage	I-Device
and	O
non-standard	O
configurations	O
of	O
HD	O
Audio	O
subsystem	O
.	O
</s>
<s>
Keyboard	B-Device
layout	O
has	O
significant	O
differences	O
between	O
Apple	B-Device
and	O
IBM	B-Device
PC	I-Device
keyboards	I-Device
.	O
</s>
<s>
While	O
PC	B-Device
keyboards	I-Device
can	O
be	O
used	O
in	O
macOS	B-Operating_System
,	O
as	O
well	O
as	O
Mac	O
keyboards	B-Device
in	O
Microsoft	B-Application
Windows	I-Application
,	O
some	O
functional	O
differences	O
occur	O
.	O
</s>
<s>
Compact	O
and	O
laptop	O
keyboards	B-Device
from	O
Apple	B-Device
also	O
lack	O
some	O
keys	O
considered	O
essential	O
on	O
PCs	B-Device
,	O
such	O
as	O
the	O
forward	O
key	O
,	O
although	O
some	O
of	O
them	O
are	O
accessible	O
through	O
the	O
key	O
.	O
</s>
<s>
All	O
Intel-based	B-Device
Macs	I-Device
have	O
been	O
using	O
some	O
version	O
of	O
EFI	B-Architecture
as	O
the	O
boot	O
firmware	B-Application
.	O
</s>
<s>
At	O
the	O
time	O
the	O
platform	O
debuted	O
in	O
2006	O
,	O
it	O
was	O
in	O
a	O
stark	O
contrast	O
to	O
PCs	B-Device
,	O
which	O
almost	O
universally	O
employed	O
legacy	B-Operating_System
BIOS	I-Operating_System
,	O
and	O
Apple	B-Device
's	O
implementation	O
of	O
EFI	B-Architecture
did	O
not	O
initially	O
implement	O
the	O
Compatibility	O
Support	O
Module	O
that	O
would	O
allow	O
booting	O
contemporary	O
standard	O
PC	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
Apple	B-Device
updated	O
the	O
firmware	B-Application
with	O
CSM	O
support	O
with	O
the	O
release	O
of	O
Boot	B-Application
Camp	I-Application
in	O
April	O
2006	O
,	O
and	O
since	O
the	O
release	O
of	O
Windows	B-Application
8	I-Application
in	O
2012	O
,	O
Microsoft	O
has	O
required	O
its	O
OEM	O
partners	O
to	O
use	O
UEFI	B-Architecture
boot	O
process	O
on	O
PCs	B-Device
,	O
which	O
made	O
the	O
differences	O
smaller	O
.	O
</s>
<s>
However	O
,	O
Apple	B-Device
's	O
version	O
of	O
EFI	B-Architecture
also	O
includes	O
some	O
custom	O
extensions	O
that	O
are	O
utilized	O
during	O
regular	O
macOS	B-Operating_System
boot	O
process	O
,	O
which	O
include	O
the	O
following	O
:	O
</s>
<s>
Drivers	B-Application
for	O
the	O
HFS	B-Application
Plus	I-Application
and	O
APFS	B-Application
file	B-Application
systems	I-Application
with	O
support	O
locating	O
the	O
bootloader	B-Application
based	O
on	O
the	O
"	O
blessed	O
directory	O
"	O
and	O
"	O
blessed	O
file	O
"	O
properties	O
of	O
HFS+	B-Application
and	O
APFS	B-Application
volumes	O
.	O
</s>
<s>
The	O
EFI	B-Device
System	I-Device
Partition	I-Device
is	O
thus	O
not	O
used	O
or	O
necessary	O
for	O
regular	O
macOS	B-Operating_System
boot	O
process	O
.	O
</s>
<s>
This	O
is	O
used	O
by	O
FileVault	O
2	O
to	O
present	O
the	O
login	O
screen	O
before	O
loading	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Other	O
non-standard	O
EFI	B-Architecture
services	O
for	O
managing	O
various	O
firmware	B-Application
features	O
such	O
as	O
the	O
computer	O
's	O
NVRAM	B-General_Concept
and	O
boot	O
arguments	O
.	O
</s>
<s>
Some	O
of	O
these	O
differences	O
can	O
pose	O
as	O
obstacles	O
both	O
to	O
running	B-Operating_System
macOS	I-Operating_System
on	I-Operating_System
non-Apple	I-Operating_System
hardware	I-Operating_System
and	O
booting	O
alternative	O
operating	B-General_Concept
systems	I-General_Concept
on	O
Mac	O
computers	O
–	O
Apple	B-Device
only	O
provides	O
drivers	B-Application
for	O
its	O
custom	O
hardware	O
for	O
macOS	B-Operating_System
and	O
Microsoft	B-Application
Windows	I-Application
(	O
as	O
part	O
of	O
Boot	B-Application
Camp	I-Application
)	O
;	O
drivers	B-Application
for	O
other	O
operating	B-General_Concept
systems	I-General_Concept
such	O
as	O
Linux	B-Application
need	O
to	O
be	O
written	O
by	O
third	O
parties	O
,	O
usually	O
volunteer	O
free	B-Application
software	I-Application
enthusiasts	O
.	O
</s>
<s>
Digital	O
rights	O
management	O
in	O
the	O
Apple	B-Device
–	I-Device
Intel	I-Device
architecture	I-Device
is	O
accomplished	O
via	O
the	O
"	O
Dont	O
Steal	O
Mac	O
OS	O
X.kext	O
,	O
"	O
sometimes	O
referred	O
to	O
as	O
DSMOS	O
or	O
DSMOSX	O
,	O
a	O
file	O
present	O
in	O
Intel-capable	O
versions	O
of	O
the	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
Its	O
presence	O
enforces	O
a	O
form	O
of	O
digital	O
rights	O
management	O
,	O
preventing	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
being	O
installed	O
on	O
stock	O
PCs	B-Device
.	O
</s>
<s>
The	O
name	O
of	O
the	O
kext	O
is	O
a	O
reference	O
to	O
the	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
license	O
conditions	O
,	O
which	O
allow	O
installation	O
on	O
Apple	B-Device
hardware	O
only	O
.	O
</s>
<s>
According	O
to	O
Apple	B-Device
,	O
anything	O
else	O
is	O
stealing	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
.	O
</s>
<s>
The	O
kext	O
is	O
located	O
at	O
/System/Library/Extensions	O
on	O
the	O
volume	O
containing	O
the	O
operating	B-General_Concept
system	I-General_Concept
.	O
</s>
<s>
The	O
extension	O
contains	O
a	O
kernel	O
function	O
called	O
that	O
performs	O
AES	B-Algorithm
decryption	O
of	O
"	O
apple-protected	O
"	O
programs	O
.	O
</s>
<s>
A	O
system	O
lacking	O
a	O
proper	O
key	O
will	O
not	O
be	O
able	O
to	O
run	O
the	O
Apple-restricted	O
binaries	O
,	O
which	O
include	O
,	O
,	O
,	O
,	O
,	O
,	O
,	O
,	O
,	O
or	O
.	O
</s>
<s>
Please	O
do	O
n't	O
steal	O
Mac	B-Application
OS	I-Application
!	O
</s>
<s>
(	O
C	O
)	O
Apple	B-Device
Computer	O
,	O
Inc.	O
"	O
</s>
<s>
After	O
the	O
initial	O
announcement	O
of	O
first	O
Intel-based	B-Device
Mac	I-Device
hardware	O
configurations	O
,	O
reporting	O
a	O
Trusted	O
Platform	O
Module	O
among	O
system	O
components	O
,	O
it	O
was	O
believed	O
that	O
the	O
TPM	O
is	O
responsible	O
for	O
handling	O
the	O
DRM	O
protection	O
.	O
</s>
<s>
The	O
keys	O
are	O
actually	O
contained	O
within	O
the	O
System	B-Device
Management	I-Device
Controller	I-Device
,	O
a	O
component	O
exclusive	O
to	O
Apple	B-Device
computers	O
,	O
and	O
can	O
be	O
easily	O
retrieved	O
from	O
it	O
.	O
</s>
<s>
These	O
two	O
32-byte	O
keys	O
form	O
a	O
human-readable	O
ASCII	O
string	O
copyrighted	O
by	O
Apple	B-Device
,	O
establishing	O
another	O
possible	O
line	O
of	O
legal	O
defence	O
against	O
prospective	O
clone	O
makers	O
.	O
</s>
<s>
The	O
Intel	O
Core	O
Duo	O
(	O
and	O
later	O
,	O
including	O
the	O
current	O
i5	O
,	O
i7	O
,	O
i9	O
,	O
and	O
Xeon	O
)	O
processors	O
found	O
in	O
Intel	B-Device
Macs	I-Device
support	O
Intel	O
VT-x	O
,	O
which	O
allows	O
for	O
high	O
performance	O
(	O
near-native	O
)	O
virtualization	B-General_Concept
that	O
gives	O
the	O
user	O
the	O
ability	O
to	O
run	O
and	O
switch	O
between	O
two	O
or	O
more	O
operating	B-General_Concept
systems	I-General_Concept
simultaneously	O
,	O
rather	O
than	O
having	O
to	O
dual-boot	B-Operating_System
and	O
run	O
only	O
one	O
operating	B-General_Concept
system	I-General_Concept
at	O
a	O
time	O
.	O
</s>
<s>
The	O
first	O
software	O
to	O
take	O
advantage	O
of	O
this	O
technology	O
was	O
Parallels	B-Language
Desktop	I-Language
for	I-Language
Mac	I-Language
,	O
released	O
in	O
June	O
2006	O
.	O
</s>
<s>
The	O
Parallels	B-Language
virtualization	B-General_Concept
products	O
allow	O
users	O
to	O
use	O
installations	O
of	O
Windows	B-Application
XP	I-Application
and	O
later	O
in	O
a	O
virtualized	O
mode	O
while	O
running	O
OS	B-Operating_System
X	I-Operating_System
.	O
VirtualBox	B-Operating_System
is	O
virtualization	B-General_Concept
software	O
from	O
Oracle	B-Application
Corporation	I-Application
,	O
which	O
was	O
released	O
January	O
2007	O
.	O
</s>
<s>
Available	O
for	O
Mac	B-Operating_System
OS	I-Operating_System
X	I-Operating_System
as	O
well	O
as	O
other	O
host	O
operating	B-General_Concept
systems	I-General_Concept
,	O
it	O
supports	O
Intel	O
VT-x	O
and	O
can	O
run	O
multiple	O
other	O
guest	O
operating	B-General_Concept
systems	I-General_Concept
,	O
including	O
Windows	B-Application
XP	I-Application
and	O
later	O
.	O
</s>
<s>
VMware	O
offers	O
a	O
product	O
similar	O
to	O
Parallels	B-Language
called	O
Fusion	B-Operating_System
,	O
released	O
August	O
2007	O
.	O
</s>
<s>
VMware	O
's	O
virtualization	B-General_Concept
product	O
also	O
allows	O
users	O
to	O
use	O
installations	O
of	O
Windows	B-Application
XP	I-Application
and	O
later	O
under	O
OS	B-Operating_System
X	I-Operating_System
.	O
</s>
<s>
Regardless	O
of	O
the	O
product	O
used	O
,	O
there	O
are	O
inherent	O
limitations	O
and	O
performance	O
penalties	O
in	O
using	O
a	O
virtualized	O
guest	O
OS	O
versus	O
the	O
native	O
macOS	B-Operating_System
or	O
booting	O
an	O
alternative	O
OS	O
solution	O
offered	O
via	O
Boot	B-Application
Camp	I-Application
.	O
</s>
