20. ACPI Machine Language (AML) Specification

This chapter formally defines the ACPI Machine Language (AML), which is the virtual machine language for ACPI control methods on an ACPI-compatible OS. ACPI control methods can be written directly in AML, but people usually write them in ASL and then compile to AML.

AML is the language processed by the ACPI AML interpreter. It is primarily a declarative language. It’s best not to think of it as a stream of code, but rather as a set of declarations that the ACPI AML interpreter will compile into the ACPI Namespace at definition block load time. For example, notice that DefByte allocates an anonymous integer variable with a byte-size initial value in ACPI namespace, and passes in an initial value. The byte in the AML stream that defines the initial value is not the address of the variable’s storage location.

An OEM or platform firmware vendor needs to write ASL and be able to single-step AML for debugging. (Debuggers and other ACPI control method language tools are expected to be AML-level tools, not source-level tools.) An ASL translator implementer must understand how to read ASL and generate AML. An AML interpreter author must understand how to execute AML.

AML and ASL are different languages, though they are closely related.

All ACPI-compatible operating systems must support AML. A given user can define some arbitrary source language (to replace ASL) and write a tool to translate it to AML. However, the ACPI group will support a single translator for a single language, ASL.

20.1. Notation Conventions

The notation conventions in the table below help the reader to interpret the AML formal grammar.

Table 20.1 AML Grammar Notation Conventions

Notation Convention

Description

Example

0xdd

Refers to a byte value expressed as 2 hexadecimal digits.

0x21

Number in bold.

Denotes the encoding of the AML term.

Term => Evaluated Type

Shows the resulting type of the evaluation of Term.

Single quotes (‘ ‘)

Indicate constant characters.

‘A’ => 0x41

Term := Term Term …

The term to the left of := can be expanded into the sequence of terms on the right.

aterm := bterm cterm means that aterm can be expanded into the two-term sequence of bterm followed by cterm.

Term Term Term …

Terms separated from each other by spaces form an ordered list.

Angle brackets (< > )

used to group items.

<a b> | <c d> means either a b or c d.

Bar symbol ( | )

Separates alternatives.

aterm := bterm | [cterm dterm] means the following constructs are possible:
bterm cterm dterm
aterm := [bterm | cterm] dterm means the following constructs are possible:
bterm dterm cterm dterm

Dash character ( - )

Indicates a range.

1-9 means a single digit in the range 1 to 9 inclusive.

Parenthesized term following another term.

The parenthesized term is the repeat count of the previous term.

aterm(3) means aterm aterm aterm. bterm(n) means n number of bterms.

20.2. AML Grammar Definition

This section defines the byte values that make up an AML byte stream.

The AML encoding can be categorized into the following groups:

  • Table and Table Header encoding

  • Name objects encoding

  • Data objects encoding

  • Package length encoding

  • Term objects encoding

  • Miscellaneous objects encoding

20.2.1. Table and Table Header Encoding

TableSignature :=

DWordData // As defined in section 5.2.3.

TableLength :=

DWordData // Length of the table in bytes including the block header.

SpecCompliance :=

ByteData // The revision of the structure.

CheckSum :=

ByteData // Byte checksum of the entire table.

OemID :=
ByteData(6) // OEM ID of up to 6 characters. If the OEM ID is shorter than 6 characters,
it can be terminated with a NULL character.
OemTableID :=
ByteData(8) // OEM Table ID of up to 8 characters. If the OEM Table ID is shorter than 8 characters,
it can be terminated with a NULL character.
OemRevision :=

DWordData // OEM Table Revision.

CreatorID :=

DWordData // Vendor ID of the ASL compiler.

CreatorRevision :=

DWordData // Revision of the ASL compiler.

20.2.2. Name Objects Encoding

LeadNameChar := ‘A’-‘Z’ | ‘_’

DigitChar := ‘0’ - ‘9’

NameChar := DigitChar | LeadNameChar

RootChar := ‘'

ParentPrefixChar := ‘^’

‘A’-‘Z’ := 0x41 - 0x5A

‘_’ := 0x5F

‘0’-‘9’ := 0x30 - 0x39

‘' := 0x5C

‘^’ := 0x5E

NameSeg :=
// Notice that NameSegs shorter than 4 characters are filled with trailing underscores (‘_’s).

NameString := <rootchar namepath> | <prefixpath namepath>

PrefixPath := Nothing | <’^’ prefixpath>

NamePath := NameSeg | DualNamePath | MultiNamePath | NullName

DualNamePath := DualNamePrefix NameSeg NameSeg

DualNamePrefix := 0x2E

MultiNamePrefix := 0x2F

SegCount := ByteData
// SegCount can be from 1 to 255. For example: MultiNamePrefix(35) is
// encoded as 0x2f 0x23 and followed by 35 NameSegs. So, the total
// encoding length will be 1 + 1 + 35*4 = 142. Notice that:
// DualNamePrefix NameSeg NameSeg has a smaller encoding than the
// encoding of: MultiNamePrefix(2) NameSeg NameSeg

SimpleName := NameString | ArgObj | LocalObj

NullName := 0x00

Target := SuperName | NullName

20.2.3. Data Objects Encoding

DataRefObject := DataObject | ObjectReference

ByteConst := BytePrefix ByteData

BytePrefix := 0x0A

WordConst := WordPrefix WordData

WordPrefix := 0x0B

DWordConst := DWordPrefix DWordData

DWordPrefix := 0x0C

QWordConst := QWordPrefix QWordData

QWordPrefix := 0x0E

StringPrefix := 0x0D

ConstObj := ZeroOp | OneOp | OnesOp

ByteList := Nothing | <bytedata bytelist>

ByteData := 0x00 - 0xFF

WordData := ByteData[0:7] ByteData[8:15]

// 0x0000-0xFFFF

DWordData := WordData[0:15] WordData[16:31]

// 0x00000000-0xFFFFFFFF

QWordData := DWordData[0:31] DWordData[32:63]

// 0x0000000000000000-0xFFFFFFFFFFFFFFFF

AsciiCharList := Nothing | <asciichar asciicharlist>

AsciiChar := 0x01 - 0x7F

NullChar := 0x00

ZeroOp := 0x00

OneOp := 0x01

OnesOp := 0xFF

RevisionOp := ExtOpPrefix 0x30

ExtOpPrefix := 0x5B

20.2.4. Package Length Encoding

PkgLength :=
<pkgleadbyte bytedata bytedata> |
<pkgleadbyte bytedata bytedata bytedata>
PkgLeadByte :=
<bit 7-6: bytedata count that follows (0-3)>
<bit 5-4: only used if pkglength < 63>
<bit 3-0: least significant package length nybble>

Note

The high 2 bits of the first byte reveal how many follow bytes are in the PkgLength. If the PkgLength has only one byte, bit 0 through 5 are used to encode the package length (in other words, values 0-63). If the package length value is more than 63, more than one byte must be used for the encoding in which case bit 4 and 5 of the PkgLeadByte are reserved and must be zero. If the multiple bytes encoding is used, bits 0-3 of the PkgLeadByte become the least significant 4 bits of the resulting package length value. The next ByteData will become the next least significant 8 bits of the resulting value and so on, up to 3 ByteData bytes. Thus, the maximum package length is 2*28.

20.2.5. Term Objects Encoding

TermList := Nothing | <termobj termlist>

MethodInvocation := NameString TermArgList

TermArgList := Nothing | <termarg termarglist>

20.2.5.1. Namespace Modifier Objects Encoding

NameSpaceModifierObj := DefAlias | DefName | DefScope

AliasOp := 0x06

NameOp := 0x08

ScopeOp := 0x10

20.2.5.2. Named Objects Encoding

BankFieldOp :=

ExtOpPrefix 0x87

BankValue :=

TermArg => Integer

FieldFlags :=
ByteData // bit 0-3: AccessType
// 0 AnyAcc
// 1 ByteAcc
// 2 WordAcc
// 3 DWordAcc
// 4 QWordAcc
// 5 BufferAcc
// 6 Reserved
// 7-15 Reserved
// bit 4: LockRule
// 0 NoLock
// 1 Lock
// bit 5-6: UpdateRule
// 0 Preserve
// 1 WriteAsOnes
// 2 WriteAsZeros
// bit 7: Reserved (must be 0)

FieldList := Nothing | <fieldelement fieldlist>

NamedField := NameSeg PkgLength

ReservedField := 0x00 PkgLength

AccessField :=

0x01 AccessType AccessAttrib

AccessType :=
ByteData // Bits 0:3 - Same as AccessType bits of FieldFlags.
// Bits 4:5 - Reserved
// Bits 7:6 - 0 = AccessAttrib = Normal Access Attributes
// 1 = AccessAttrib = AttribBytes (x)
// 2 = AccessAttrib = AttribRawBytes (x)
// 3 = AccessAttrib = AttribRawProcessBytes (x)
//
// x’ is encoded as bits 0:7 of the AccessAttrib byte.
AccessAttrib :=
ByteData // If AccessType is BufferAcc for the SMB or
// GPIO OpRegions, AccessAttrib can be one of
// the following values:
// 0x02 AttribQuick
// 0x04 AttribSendReceive
// 0x06 AttribByte
// 0x08 AttribWord
// 0x0A AttribBlock
// 0x0C Attrib ProcessCall
// 0x0D AttribBlockProcessCall
ConnectField :=

<0x02 NameString> | <0x02 BufferData

CreateBitFieldOp := 0x8D

SourceBuff :=

TermArg => Buffer

BitIndex :=

TermArg => Integer

CreateByteFieldOp := 0x8C

ByteIndex :=

TermArg => Integer

CreateDWordFieldOp := 0x8A

CreateFieldOp :=

ExtOpPrefix 0x13

NumBits :=

TermArg => Integer

CreateQWordFieldOp := 0x8F

CreateWordFieldOp := 0x8B

DefDataRegion := DataRegionOp NameString TermArg TermArg TermArg

DataRegionOp := ExOpPrefix 0x88

DeviceOp := ExtOpPrefix 0x82

DefEvent := EventOp NameString

EventOp := ExtOpPrefix 0x02

ExternalOp := 0x15

ObjectType := ByteData

ArgumentCount := ByteData (0 - 7)

FieldOp := ExtOpPrefix 0x81

IndexFieldOp := ExtOpPrefix 0x86

MethodOp := 0x14

MethodFlags :=
ByteData // bit 0-2: ArgCount (0-7)
// bit 3: SerializeFlag
// 0 NotSerialized
// 1 Serialized
// bit 4-7: SyncLevel (0x00-0x0f)

MutexOp := ExtOpPrefix 0x01

SyncFlags := ByteData // bits 0-3: SyncLevel (0x00-0x0f), bits 4-7: Reserved (must be 0)

OpRegionOp := ExtOpPrefix 0x80

RegionSpace :=
ByteData // 0x00 SystemMemory
// 0x01 SystemIO
// 0x02 PCI_Config
// 0x03 EmbeddedControl
// 0x04 SMBus
// 0x05 System CMOS
// 0x06 PciBarTarget
// 0x07 IPMI
// 0x08 GeneralPurposeIO
// 0x09 GenericSerialBus
// 0x0A PCC
// 0x80-0xFF: OEM Defined

RegionOffset := TermArg => Integer

RegionLen := TermArg => Integer

PowerResOp := ExtOpPrefix 0x84

SystemLevel := ByteData

ResourceOrder := WordData

ProcID := ByteData

PblkAddr := DWordData

PblkLen := ByteData

ThermalZoneOp := ExtOpPrefix 0x85

ExtendedAccessField := 0x03 AccessType ExtendedAccessAttrib AccessLength

ExtendedAccessAttrib :=

ByteData // 0x0B AttribBytes, 0x0E AttribRawBytes, 0x0F AttribRawProcess

20.2.5.3. Statement Opcodes Encoding

DefBreak := BreakOp

BreakOp := 0xA5

DefBreakPoint := BreakPointOp

BreakPointOp := 0xCC

DefContinue := ContinueOp

ContinueOp := 0x9F

DefElse := Nothing | <elseop pkglength termlist>

ElseOp := 0xA1

FatalOp := ExtOpPrefix 0x32

FatalType := ByteData

FatalCode := DWordData

FatalArg := TermArg => Integer

IfOp := 0xA0

Predicate := TermArg => Integer

DefNoop := NoopOp

NoopOp := 0xA3

NotifyOp := 0x86

NotifyObject := SuperName => ThermalZone | Processor | Device

NotifyValue := TermArg => Integer

DefRelease := ReleaseOp MutexObject

ReleaseOp := ExtOpPrefix 0x27

MutexObject := SuperName

DefReset := ResetOp EventObject

ResetOp := ExtOpPrefix 0x26

EventObject := SuperName

DefReturn := ReturnOp ArgObject

ReturnOp := 0xA4

ArgObject := TermArg => DataRefObject

DefSignal := SignalOp EventObject

SignalOp := ExtOpPrefix 0x24

DefSleep := SleepOp MsecTime

SleepOp := ExtOpPrefix 0x22

MsecTime := TermArg => Integer

DefStall := StallOp UsecTime

StallOp := ExtOpPrefix 0x21

UsecTime := TermArg => ByteData

WhileOp := 0xA2

20.2.5.4. Expression Opcodes Encoding

ReferenceTypeOpcode := DefRefOf | DefDerefOf | DefIndex | UserTermObj

AcquireOp := ExtOpPrefix 0x23

Timeout := WordData

AddOp := 0x72

Operand := TermArg => Integer

AndOp := 0x7B

BufferOp := 0x11

BufferSize := TermArg => Integer

DefConcat := ConcatOp Data Data Target

ConcatOp := 0x73

Data := TermArg => ComputationalData

ConcatResOp := 0x84

BufData := TermArg => Buffer

DefCondRefOf := CondRefOfOp SuperName Target

CondRefOfOp := ExtOpPrefix 0x12

DefCopyObject := CopyObjectOp TermArg SimpleName

CopyObjectOp := 0x9D

DefDecrement := DecrementOp SuperName

DecrementOp := 0x76

DefDerefOf := DerefOfOp ObjReference

DerefOfOp := 0x83

ObjReference := TermArg => ObjectReference | String

DivideOp := 0x78

Dividend := TermArg => Integer

Divisor := TermArg => Integer

Remainder := Target

Quotient := Target

DefFindSetLeftBit := FindSetLeftBitOp Operand Target

FindSetLeftBitOp := 0x81

DefFindSetRightBit := FindSetRightBitOp Operand Target

FindSetRightBitOp := 0x82

DefFromBCD := FromBCDOp BCDValue Target

FromBCDOp := ExtOpPrefix 0x28

BCDValue := TermArg => Integer

DefIncrement := IncrementOp SuperName

IncrementOp := 0x75

IndexOp := 0x88

BuffPkgStrObj := TermArg => Buffer, Package, or String

IndexValue := TermArg => Integer

DefLAnd := LandOp Operand Operand

LandOp := 0x90

DefLEqual := LequalOp Operand Operand

LequalOp := 0x93

DefLGreater := LgreaterOp Operand Operand

LgreaterOp := 0x94

DefLGreaterEqual := LgreaterEqualOp Operand Operand

LgreaterEqualOp := LnotOp LlessOp

DefLLess := LlessOp Operand Operand

LlessOp := 0x95

DefLLessEqual := LlessEqualOp Operand Operand

LlessEqualOp := LnotOp LgreaterOp

DefLNot := LnotOp Operand

LnotOp := 0x92

DefLNotEqual := LnotEqualOp Operand Operand

LnotEqualOp := LnotOp LequalOp

LoadOp := ExtOpPrefix 0x20

LoadTableOp := ExtOpPrefix 0x1F

DefLOr := LorOp Operand Operand

LorOp := 0x91

MatchOp := 0x89

SearchPkg := TermArg => Package

MatchOpcode :=
ByteData // 0 MTR
// 1 MEQ
// 2 MLE
// 3 MLT
// 4 MGE
// 5 MGT

StartIndex := TermArg => Integer

MidOp := 0x9E

MidObj := TermArg => Buffer | String

ModOp := 0x85

MultiplyOp := 0x77

NandOp := 0x7C

NorOp := 0x7E

DefNot := NotOp Operand Target

NotOp := 0x80

ObjectTypeOp := 0x8E

DefOr := OrOp Operand Operand Target

OrOp := 0x7D

PackageOp := 0x12

VarPackageOp := 0x13

NumElements := ByteData

VarNumElements := TermArg => Integer

PackageElementList := Nothing | <packageelement packageelementlist>

PackageElement := DataRefObject | NameString

DefRefOf := RefOfOp SuperName

RefOfOp := 0x71

ShiftLeftOp := 0x79

ShiftCount := TermArg => Integer

ShiftRightOp := 0x7A

DefSizeOf := SizeOfOp SuperName

SizeOfOp := 0x87

StoreOp := 0x70

SubtractOp := 0x74

DefTimer := TimerOp

TimerOp := 0x5B 0x33

DefToBCD := ToBCDOp Operand Target

ToBCDOp := ExtOpPrefix 0x29

DefToBuffer := ToBufferOp Operand Target

ToBufferOp := 0x96

DefToDecimalString := ToDecimalStringOp Operand Target

ToDecimalStringOp := 0x97

DefToHexString := ToHexStringOp Operand Target

ToHexStringOp := 0x98

DefToInteger := ToIntegerOp Operand Target

ToIntegerOp := 0x99

LengthArg := TermArg => Integer

ToStringOp := 0x9C

WaitOp := ExtOpPrefix 0x25

XorOp := 0x7F

20.2.6. Miscellaneous Objects Encoding

Miscellaneous objects include:

  • Arg objects

  • Local objects

  • Debug objects

20.2.6.1. Arg Objects Encoding

ArgObj := Arg0Op | Arg1Op | Arg2Op | Arg3Op | Arg4Op | Arg5Op | Arg6Op

Arg0Op := 0x68

Arg1Op := 0x69

Arg2Op := 0x6A

Arg3Op := 0x6B

Arg4Op := 0x6C

Arg5Op := 0x6D

Arg6Op := 0x6E

20.2.6.2. Local Objects Encoding

LocalObj := Local0Op | Local1Op | Local2Op | Local3Op | Local4Op | Local5Op | Local6Op | Local7Op

Local0Op := 0x60

Local1Op := 0x61

Local2Op := 0x62

Local3Op := 0x63

Local4Op := 0x64

Local5Op := 0x65

Local6Op := 0x66

Local7Op := 0x67

20.2.6.3. Debug Objects Encoding

DebugObj := DebugOp

DebugOp := ExtOpPrefix 0x31

20.3. AML Byte Stream Byte Values

The following table lists all byte values that can be found in an AML byte stream, and the meaning of each byte value. This table is useful for debugging AML code.

Table 20.2 AML Byte Stream Byte Values

Encoding Value

Encoding Name

Encoding Group

Fixed List Arguments

Variable List Arguments

0x00

ZeroOp

Data Object

0x01

OneOp

Data Object

0x02-0x05

0x06

AliasOp

Term Object

NameString NameString

0x07

0x08

NameOp

Term Object

NameString DataRefObject

0x09

0x0A

BytePrefix

Data Object

ByteData

0x0B

WordPrefix

Data Object

WordData

0x0C

DWordPrefix

Data Object

DWordData

0x0D

StringPrefix

Data Object

AsciiCharList NullChar

0x0E

QWordPrefix

Data Object

QWordData

0x0F

0x10

ScopeOp

Term Object

NameString

TermList

0x11

BufferOp

Term Object

TermArg

ByteList

0x12

PackageOp

Term Object

ByteData

Package TermList

0x13

VarPackageOp

Term Object

TermArg

Package TermList

0x14

MethodOp

Term Object

NameString ByteData

TermList

0x15

ExternalOp

Name Object

NameString ByteData ByteData

0x16-0x2D

0x2E (‘.’)

DualNamePrefix

Name Object

NameSeg NameSeg

0x2F (‘/’)

MultiNamePrefix

Name Object

ByteData NameSeg(N)

0x30-0x39 (‘0’-‘9’)

DigitChar

Name Object

0x3A-0x40

0x41-0x5A (‘A’-‘Z’)

NameChar

Name Object

0x5B (‘[‘)

ExtOpPrefix

ByteData

0x5B 0x00

0x5B 0x01

MutexOp

Term Object

NameString ByteData

0x5B 0x02

EventOp

Term Object

NameString

0x5B 0x12

CondRefOfOp

Term Object

SuperName SuperName

0x5B 0x13

CreateFieldOp

Term Object

TermArg TermArg TermArg NameString

0x5B 0x1F

LoadTableOp

Term Object

TermArg TermArg TermArg TermArg TermArg TermArg

0x5B 0x20

LoadOp

Term Object

NameString SuperName

0x5B 0x21

StallOp

Term Object

TermArg

0x5B 0x22

SleepOp

Term Object

TermArg

0x5B 0x23

AcquireOp

Term Object

SuperName WordData

0x5B 0x24

SignalOp

Term Object

SuperName

0x5B 0x25

WaitOp

Term Object

SuperName TermArg

0x5B 0x26

ResetOp

Term Object

SuperName

0x5B 0x27

ReleaseOp

Term Object

SuperName

0x5B 0x28

FromBCDOp

Term Object

TermArg Target

0x5B 0x29

ToBCD

Term Object

TermArg Target

0x5B 0x2A

Reserved

0x5B 0x30

RevisionOp

Data Object

0x5B 0x31

DebugOp

Debug Object

0x5B 0x32

FatalOp

Term Object

ByteData DWordData TermArg

0x5B 0x33

TimerOp

Term Object

0x5B 0x80

OpRegionOp

Term Object

NameString ByteData TermArg TermArg

0x5B 0x81

FieldOp

Term Object

NameString ByteData

FieldList

0x5B 0x82

DeviceOp

Term Object

NameString

TermList

0x5B 0x83

Permanently Reserved

Use of this opcode for ProcessorOp was deprecated in ACPI 6.4, and is not to be reused.

0x5B 0x84

PowerResOp

Term Object

NameString ByteData WordData

TermList

0x5B 0x85

ThermalZoneOp

Term Object

NameString

TermList

0x5B 0x86

IndexFieldOp

Term Object

NameString NameString ByteData

FieldList

0x5B 0x87

BankFieldOp

Term Object

NameString NameString TermArg ByteData

FieldList

0x5B 0x88

DataRegionOp

Term Object

NameString TermArg TermArg TermArg

0x5B 0x80 - 0x5B 0xFF

0x5C (‘\’)

RootChar

Name Object

0x5D

0x5E (‘^’)

ParentPrefixChar

Name Object

0x5F(‘_’)

NameChar—

Name Object

0x60 (‘`’)

Local0Op

Local Object

0x61 (‘a’)

Local1Op

Local Object

0x62 (‘b’)

Local2Op

Local Object

0x63 (‘c’)

Local3Op

Local Object

0x64 (‘d’)

Local4Op

Local Object

0x65 (‘e’)

Local5Op

Local Object

0x66 (‘f’)

Local6Op

Local Object

0x67 (‘g’)

Local7Op

Local Object

0x68 (‘h’)

Arg0Op

Arg Object

0x69 (‘i’)

Arg1Op

Arg Object

0x6A (‘j’)

Arg2Op

Arg Object

0x6B (‘k’)

Arg3Op

Arg Object

0x6C (‘l’)

Arg4Op

Arg Object

0x6D (‘m’)

Arg5Op

Arg Object

0x6E (‘n’)

Arg6Op

Arg Object

0x6F

0x70

StoreOp

Term Object

TermArg SuperName

0x71

RefOfOp

Term Object

SuperName

0x72

AddOp

Term Object

TermArg TermArg Target

0x73

ConcatOp

Term Object

TermArg TermArg Target

0x74

SubtractOp

Term Object

TermArg TermArg Target

0x75

IncrementOp

Term Object

SuperName

0x76

DecrementOp

Term Object

SuperName

0x77

MultiplyOp

Term Object

TermArg TermArg Target

0x78

DivideOp

Term Object

TermArg TermArg Target Target

0x79

ShiftLeftOp

Term Object

TermArg TermArg Target

0x7A

ShiftRightOp

Term Object

TermArg TermArg Target

0x7B

AndOp

Term Object

TermArg TermArg Target

0x7C

NandOp

Term Object

TermArg TermArg Target

0x7D

OrOp

Term Object

TermArg TermArg Target

0x7E

NorOp

Term Object

TermArg TermArg Target

0x7F

XorOp

Term Object

TermArg TermArg Target

0x80

NotOp

Term Object

TermArg Target

0x81

FindSetLeftBitOp

Term Object

TermArg Target

0x82

FindSetRightBitOp

Term Object

TermArg Target

0x83

DerefOfOp

Term Object

TermArg

0x84

ConcatResOp

Term Object

TermArg TermArg Target

0x85

ModOp

Term Object

TermArg TermArg Target

0x86

NotifyOp

Term Object

SuperName TermArg

0x87

SizeOfOp

Term Object

SuperName

0x88

IndexOp

Term Object

TermArg TermArg Target

0x89

MatchOp

Term Object

TermArg ByteData TermArg ByteData TermArg TermArg

0x8A

CreateDWordFieldOp

Term Object

TermArg TermArg NameString

0x8B

CreateWordFieldOp

Term Object

TermArg TermArg NameString

0x8C

CreateByteFieldOp

Term Object

TermArg TermArg NameString

0x8D

CreateBitFieldOp

Term Object

TermArg TermArg NameString

0x8E

ObjectTypeOp

Term Object

SuperName

0x8F

CreateQWordFieldOp

Term Object

TermArg TermArg NameString

0x90

LandOp

Term Object

TermArg TermArg

0x91

LorOp

Term Object

TermArg TermArg

0x92

LnotOp

Term Object

TermArg

0x92 0x93

LNotEqualOp

Term Object

TermArg TermArg

0x92 0x94

LLessEqualOp

Term Object

TermArg TermArg

0x92 0x95

LGreaterEqualOp

Term Object

TermArg TermArg

0x93

LEqualOp

Term Object

TermArg TermArg

0x94

LGreaterOp

Term Object

TermArg TermArg

0x95

LLessOp

Term Object

TermArg TermArg

0x96

ToBufferOp

Term Object

TermArg Target

0x97

ToDecimalStringOp

Term Object

TermArg Target

0x98

ToHexStringOp

Term Object

TermArg Target

0x99

ToIntegerOp

Term Object

TermArg Target

0x9A-0x9B

0x9C

ToStringOp

Term Object

TermArg TermArg Target

0x9D

CopyObjectOp

Term Object

TermArg SimpleName

0x9E

MidOp

Term Object

TermArg TermArg TermArg Target

0x9F

ContinueOp

Term Object

0xA0

IfOp

Term Object

TermArg

TermList

0xA1

ElseOp

Term Object

TermList

0xA2

WhileOp

Term Object

TermArg

TermList

0xA3

NoopOp

Term Object

0xA4

ReturnOp

Term Object

TermArg

0xA5

BreakOp

Term Object

0xA6-0xCB

0xCC

BreakPointOp

Term Object

0xCD-0xFE

0xFF

OnesOp

Data Object

20.4. AML Encoding of Names in the Namespace

Assume the following namespace exists:

\\
S0
  MEM
    SET
    GET
S1
  MEM
    SET
    GET
  CPU
    SET
    GET

Assume further that a definition block is loaded that creates a node \S0.CPU.SET, and loads a block using it as a root. Assume the loaded block contains the following names:

STP1
^GET
^^PCI0
^^PCI0.SBS
\\S2
\\S2.ISA.COM1
^^^S3
^^^S2.MEM
^^^S2.MEM.SET
Scope(\S0.CPU.SET.STP1) {
  XYZ
  ^ABC
  ^ABC.DEF
}

This will be encoded in AML as:

'STP1'
ParentPrefixChar 'GET_'
ParentPrefixChar ParentPrefixChar 'PCI0'
ParentPrefixChar ParentPrefixChar DualNamePrefix 'PCI0' 'SBS_'
RootChar 'S2__'
RootChar MultiNamePrefix 3 'S2__' 'ISA_' 'COM1'
ParentPrefixChar ParentPrefixChar ParentPrefixChar 'S3__'
ParentPrefixChar ParentPrefixChar ParentPrefixChar DualNamePrefix 'S2__' 'MEM_'
ParentPrefixChar ParentPrefixChar ParentPrefixChar MultiNamePrefix 3 'S2__' 'MEM_' 'SET_'

After the block is loaded, the namespace will look like this (names added to the namespace by the loading operation are shown in bold):

\\
  S0
    MEM
      SET
      GET
    CPU
      SET
        STP1
          XYZ
        ABC
          DEF
      GET
    PCI0
      SBS
  S1
    MEM
      SET
      GET
    CPU
      SET
      GET
  S2
    ISA
      COM1
    MEM
      SET
  S3