Advanced Configuration and Power Interface Specification

ACPI Software Programming Model
NFIT Structures[n] _ 40 A list of NFIT structures for this
implementation.
Each NFIT Structure Type must start with a 2 byte Type field followed by a 2 byte length field. This
allows OSPM to ignore unrecognized types. Supported NFIT Structure Types are listed in Table 5-
127.
Table 5-127 NFIT Structure Types
Value
Description
0 System Physical Address Range Structure
1 Memory Device to System Address Range Map Structure
2 Interleave Structure
3 SMBIOS Management Information Structure
4 NVDIMM Control Region Structure
5 NVDIMM Block Data Window Region Structure
6 Flush Hint Address Structure
7-0xFFFF Reserved.
5.2.25.1 System Physical Address Range Structure
This structure describes the system physical address ranges occupied by NVDIMMs and the types of
the regions. This structure is also used to describe Volatile Memory Region, Virtual CD Region and
Virtual Disk Region.
System physical address ranges described as address type Virtual CD or Virtual Disk shall be
described as EFI Runtime Services Data in UEFI GetMemoryMap API (AddressRangeReserved in
E820 Table).
If a region is described as Virtual CD Region – Persistent or Virtual Disk Region – Persistent,
platform firmware also has to describe this region as part of a byte addressable persistent memory
address range.
OSPM has to exclude the ranges of type Virtual CD Region - Persistent or Virtual Disk Region -
Persistent from the contiguous address ranges described by this structure as byte addressable
persistent memory.
If a region is described as Virtual CD Region – Volatile or Virtual Disk Region – Volatile and if
those ranges are also described by an entry in this structure of type Volatile Memory Region, OSPM
has to exclude these ranges.
Platform is allowed to implement this structure just to describe system physical address ranges that
describe Virtual CD and Virtual Disk. For Virtual CD Region and Virtual Disk Region (both volatile
and persistent), the following fields - Proximity Domain, SPA Range Structure Index, Flags, and
Address Range Memory Mapping Attribute, are not relevant and shall be set to 0.
The default mapping of the NVDIMM Control Region shall be UC memory attributes with
AddressRangeReserved type in E820 and EfiMemoryMappedIO type in UEFI GetMemoryMap. The
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