x00-0xFF WordConst := Integer => 0x0000-0xFFFF

ByteConst := Integer => 0x00-0xFF

WordConst := Integer => 0x0000-0xFFFF

DWordConst := Integer => 0x00000000-0xFFFFFFFF

QWordConst := Integer => 0x0000000000000000-0xFFFFFFFFFFFFFFFF

Numeric constants can be specified in decimal, octal, or hexadecimal. Octal constants are preceded by a leading zero (0), and hexadecimal constants are preceded by a leading zero and either a lower or upper case ‘x’. In some cases, the grammar specifies that the number must evaluate to an integer within a limited range, such as 0x00–0xFF, and so on.

2. 
   Strings
   

String := ‘”’ Utf8CharList ‘”’

Utf8CharList := Nothing | |

Utf8Char := 0x01-0x21 |

0x23-0x5B |

0x5D-0x7F |

0xC2-0xDF 0x80-0xBF |

0xE0 0xA0-0xBF 0x80-0xBF |

0xE1-0xEC 0x80-0xBF 0x80-0xBF |

0xED 0x80-0x9F 0x80-0xBF |

0xEE-0xEF 0x80-0xBF 0x80-0xBF |

0xF0 0x90-0xBF 0x80-0xBF 0x80-0xBF |

0xF1-0xF3 0x80-0xBF 0x80-0xBF 0x80-0xBF |

0xF4 0x80-0x8F 0x80-0xBF 0x80-0xBF

EscapeSeq := SimpleEscapeSeq | OctalEscapeSeq | HexEscapeSeq

SimpleEscapeSeq := \' | \" | \a | \b | \f | \n | \r | \t | \v | \\

OctalEscapeSeq := \ OctalDigitChar |

\ OctalDigitChar OctalDigitChar |

\ OctalDigitChar OctalDigitChar OctalDigitChar

HexEscapeSeq := \x HexDigitChar |

NullChar := 0x00

String literals consist of zero or more ASCII characters surrounded by double quotation marks ("). A string literal represents a sequence of characters that, taken together, form a null-terminated string. After all adjacent strings in the constant have been concatenated, a null character is appended.

Strings in the source file may be encoded using the UTF-8 encoding scheme as defined in the Unicode 4.0 specification. UTF-8 is a byte-oriented encoding scheme, where some characters take a single byte and others take multiple bytes. The ASCII character values 0x01-0x7F take up exactly one byte.

However, only one operator currently supports UTF-8 strings: Unicode. Since string literals are defined to contain only non-null character values, both Hex and Octal escape sequence values must be non-null values in the ASCII range 0x01 through 0xFF. For arbitrary byte data (outside the range of ASCII values), the Buffer object should be used instead.

Since the backslash is used as the escape character and also the namespace root prefix, any string literals that are to contain a fully qualified namepath from the root of the namespace must use the double backslash to indicate this:

Name (_EJD, ”\\_SB.PCI0.DOCK1”)

The double backslash is only required within quoted string literals.

Since double quotation marks are used close a string, a special escape sequence (\") is used to allow quotation marks within strings. Other escape sequences are listed in the table below:
Table 18 4 ASL Escape Sequences

Store (“ABC”, ”DEF”)

However, the following sequence of statements is supported:
Name (STR, ”DEF”)

...
Store (“ABC”, STR)

3. 
      ASL Resource Templates
   

{

// List of resource macros

The following is an example of how these macros can be used to create a resource template that can be returned from a _PRS control method:

{

StartDependentFn (1, 1)

IRQ (Level, ActiveLow, Shared) {10, 11}

DMA (TypeF, NotBusMaster, Transfer16) {4}

IO (Decode16, 0x1000, 0x2000, 0, 0x100)

IO (Decode16, 0x5000, 0x6000, 0, 0x100, IO1)

}

StartDependentFn (1, 1)

IRQ (Level, ActiveLow, Shared) {}

DMA (TypeF, NotBusMaster, Transfer16){5}

IO (Decode16, 0x3000, 0x4000, 0, 0x100)

IO (Decode16, 0x5000, 0x6000, 0, 0x100, IO2)

}

EndDependentFn ()

Occasionally, it is necessary to change a parameter of a descriptor in an existing resource template at run-time (i.e., during a method execution.) To facilitate this, the descriptor macros optionally include a name declaration that can be used later to refer to the descriptor. When a name is declared with a descriptor, the ASL compiler will automatically create field names under the given name to refer to individual fields in the descriptor.

The offset returned by a reference to a resource descriptor field name is either in units of bytes (for 8-, 16-, 32-, and 64-bit field widths) or in bits (for all other field widths). In all cases, the returned offset is the integer offset (in either bytes or bits) of the name from the first byte (offset 0) of the parent resource template.

For example, given the above resource template, the following code changes the minimum and maximum addresses for the I/O descriptor named IO2:

Store (0xA000, IMIN)

Store (0xB000, IMAX)

The resource template macros for each of the resource descriptors are listed below, after the table that defines the resource descriptor. The resource template macros are formally defined in section 15, “Memory.”

The reserved names (such as _MIN and _MAX) for the fields of each resource descriptor are defined in the appropriate table entry of the table that defines that resource descriptor.

4. 
      ASL Macros
   

Table 18-5   Example ASL Built-in Macros

5. 
      ASL Data Types
   

The table below describes each of the available data types.