Advanced Configuration and Power Interface Specification

ACPI Source Language (ASL)Reference
Description
Function declares a named package containing a series of terms that collectively represent a control
method. A control method is a procedure that can be invoked to perform computation. Function
opens a name scope.
System software executes a control method by executing the terms in the package in order. For more
information on method execution, see Section 5.5.2, “Control Method Execution.”
The current namespace location used during name creation is adjusted to be the current location on
the namespace tree. Any names created within this scope are “below” the name of this package. The
current namespace location is assigned to the method package, and all namespace references that
occur during control method execution for this package are relative to that location.
Functions are equivalent to a Method that specifies NotSerialized. As such, a function should not
create any named objects, since a second thread that might re-enter the function will cause a fatal
error if an attempt is made to create the same named object twice.
Note: (Compatibility Note) New for ACPI 3.0
Example
The following block of ASL sample code shows the use of Function for defining a control method:
Function (EXAM, IntObj, {StrObj, {IntObj, StrObj}})
{
}
Name (Temp,””)
Store (Arg0, Temp)
// could have used Arg1
Return (SizeOf (Concatenate (Arg1, Temp)))
This declaration is equivalent to:
Method (EXAM, 2, NotSerialized, 0, IntObj, {StrObj, {IntObj, StrObj}})
{
…
}
19.6.54 GpioInt (GPIO Interrupt Connection Resource Descriptor
Macro)
GpioInt (EdgeLevel, ActiveLevel, Shared, PinConfig, DebounceTimeout, ResourceSource,
ResourceSourceIndex, ResourceUsage, DescriptorName, VendorData) {PinList}
Arguments
EdgeLevel can be either Edge or Level. The bit field name _MOD is automatically created to refer
to this portion of the resource descriptor.
ActiveLevel can be one of ActiveHigh, ActiveLow or ActiveBoth. ActiveBoth can be specified
only if EdgeLevel is Edge. The bit field name _POL is automatically created to refer to this portion
of the resource descriptor.
Shared is an optional argument and can be one of Shared, Exclusive, SharedAndWake or
ExclusiveAndWake. If not specified, Exclusive is assumed. The "Wake" designation indicates that
the interrupt is capable of waking the system from a low-power idle state or a system sleep state. The
bit field name _SHR is automatically created to refer to this portion of the resource descriptor.
Version 6.0 843