Appendix C: Deprecated Content

This section will list content (if any) that is being deprecated from the ACPI specification in this release.

Removing the section ID structure - Type 2, which was section in ACPI Spec 6.3A.

The ID type structure is described in the following table. The ID structure can be used to provide an ID (or vendor specific part number) for a particular processor hierarchy node structure. The ID structure is optional, and may be used by software to determine special features and/or errata workarounds for that processor hierarchy node. This ID structure can also be used to identify all underlying hierarchy nodes and components, which may include identifying proprietary hardware components that are not explicitly described in this table.

This ID structure would typically be used to describe an ID of a physical package node, but may be optionally used at any node level.

Example: In the case where this ID structure is used to uniquely describe a physical package node, it could represent a single system-on-chip (SoC) on a single die and all nodes and components within that node (e.g. processors, caches, system buses and DMA engines, interrupt controllers, on-chip peripherals, etc.). The silicon vendor of this SoC has a known erratum with a particular hardware component in that SoC that could impact behavior and/or correctness. An operating system vendor may query this ID structure to first determine the silicon vendor, then later acquire the remaining ID fields to determine part number, matching it against the part with a known erratum. The operating system may then remedy errata by either disabling relevant features or applying an appropriate software work around.

Table 3 ID Type Structure


Byte Length

Byte Offset





2 - ID structure








Must be zero




This identifies the node vendor using the vendor ACPI ID as described in the ACPI ID registry at




Vendor specific value to identify first level unique node ID (e.g. chip family ID)




Vendor specific value to identify second level unique node ID (e.g. chip ID)




Vendor specific value to identify major revision of the node




Vendor specific value to identify minor revision of the node




Vendor specific value to identify spin revision of the node

In the _PDC (Processor Driver Capabilities) section, removed the following description and left the backward-compatibility note that follows. Per feedback on the ACPI 6.4 draft spec.

This optional object is a method that is used by OSPM to communicate to the platform the level of processor power management support provided by OSPM. This object is a child object of the processor. OSPM evaluates _PDC prior to evaluating any other processor power management objects returning configuration information.

The _PDC object provides OSPM a mechanism to convey to the platform the capabilities supported by OSPM for processor power management. This allows the platform to modify the ACPI namespace objects returning configuration information for processor power management based on the level of support provided by OSPM. Using this method provides a mechanism for OEMs to provide support for new technologies on legacy OSes, while also allowing OSPM to leverage new technologies on platforms capable of supporting them. This method is evaluated once during processor device initialization, and will not be re-evaluated during resume from a sleep state transition. The platform must preserve state information across S1-S3 sleep state transitions.

Arguments: (1)

Arg0 - A variable-length Buffer containing a list of capabilities as described below.

Return Value:


The buffer argument contains a list of DWORDs in the following format:

  • RevisionId - Revision of the buffer format

  • Count - The number of capability values in the capabilities array

  • Capabilities[Count] - Capabilities array

Each DWORD entry in the capabilities array is a bitfield that defines capabilities and features supported by OSPM for processor configuration and power management as specified by the CPU manufacturer.

In the Named Objects Encoding section, removed the following definitions:

DefProcessor := ProcessorOp PkgLength NameString ProcID PblkAddr PblkLen TermList

ProcessorOp := ExtOpPrefix 0x83

In the DESCRIPTION_HEADER Signatures for tables reserved by ACPI, removed the following item for Mantis 2033:

“DPPT” DMA Protection Policy Table. See Links to ACPI-Related Documents under the heading “DMA Protection Policy Table”.

Processor (Declare Processor)

This Operator was deprecated by Mantis 1232 for ACPI Spec 6.0 in February, 2015. Some remaining references were removed for ACPI Spec 6.4 in February, 2021.