Advanced Configuration and Power Interface Specification

ACPI-Defined Devices and Device-Specific Objects
type as well as the specific implementation within that type. This allows for variability across
vendors as well as within vendor offerings. Region Format Interface Code consists of a Class Code
and an Interface Code as specified by JEDEC SPD Annex L: Serial Presence Detect for DDR4
SDRAM NVDIMM Revision 0.5 or greater (Item 2220.01).
The NVDIMM Firmware Interface Table enables loading of drivers for managing the NVDIMM as
well as for handling the address ranges supported by the NVDIMM. Region Format Interface Code
is used to load the generic drivers for the following: management driver, persistent memory driver
and block driver. A Vendor specific driver for each of the above can be loaded by matching on
Vendor ID, Device ID and Revision ID (in addition to the Region Format Interface Code).
Region Format Interface Code requirements shall be met by all compliant NVDIMMs. Any Vendor
specific extensions are only allowed to extend on top of the Region Format Interface Code
requirements.
It is assumed that the OSPM on parsing the NVDIMM Firmware Interface Table is capable of
loading the Region Format Interface Code specific driver or vendor specific drivers based on such
discovery. This scheme is as shown in Figure 9-58.
Figure 9-58 Vendor/Device Specific Driver Loading
The Subsystem Vendor ID, Subsystem Device ID and Subsystem Revision ID fields allow selection
of specific solution provider drivers that may span across devices from multiple vendors.
9.20.1 Hot Plug Support
The NVDIMM memory hot plug representation of the ACPI Name Space is described in this
section. The NVDR device is the NVDIMM root device, the NVD1 and NVD2 are NVDIMM
devices, the MEM0 is memory module device corresponding to the NVD1 and NVD2 devices. The
_FIT method under NVDR device returns all NFIT entries including the hot added devices.
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