Advanced Configuration and Power Interface Specification

ACPI Software Programming Model
Name Description Heading
_TZM
_TZP
Thermal Zone Member – returns a reference to the thermal
zone of which a device is a member.
Thermal Zone Polling – returns a Thermal zone’s polling
frequency.
Section 11.4.24 page 622
Section 11.4.25 page 622
_UID Unique ID – return a device’s unique persistent ID. Section 6.1.12 page 293
_UPC USB Port Capabilities – returns a list of USB port capabilities. Section 9.13 page 524
_UPD User Presence Detect – returns user detection information. Section 9.16.1 page 537
_UPP User Presence Polling – returns the recommended user Section 9.16.2 page 537
presence polling interval.
_VEN Vendor-defined Data – Vendor-defined data for a GPIO or Section 19.6.54 page 843
SerialBus connection, resource descriptor field
_VPO Video Post Options – returns the implemented video post Section B.3.6 page 976
options.
_WAK Wake – inform AML that the system has just awakened. Section 7.4.5 page 415
_Wxx Wake Event – method executed as a result of a wake event. Section 5.6.4.2.2 page 247
5.7 Predefined Objects
The AML interpreter of an ACPI compatible operating system supports the evaluation of a number
of predefined objects. The objects are considered “built in” to the AML interpreter on the target
operating system.
A list of predefined object names are shown in the following table.
Table 5-163 Predefined Object Names
Name
\_GL
\_OS
\_OSI
\_REV
Description
Global Lock mutex
Name of the operating system
Operating System Interface support
Revision of the ACPI specification that is implemented
5.7.1 \_GL (Global Lock Mutex)
This predefined object is a Mutex object that behaves like a Mutex as defined in Section 19.6.86,
“Mutex (Declare Synchronization/Mutex Object),” with the added behavior that acquiring this
Mutex also acquires the shared environment Global Lock defined in Section 5.2.10.1, “Global
Lock.” This allows Control Methods to explicitly synchronize with the Global Lock if necessary.
5.7.2 _OSI (Operating System Interfaces)
This object provides the platform with the ability to query OSPM to determine the set of ACPI
related interfaces, behaviors, or features that the operating system supports.
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