PEP_ACPI_EXTENDED_ADDRESS structure (pepfx.h)

The PEP_ACPI_EXTENDED_ADDRESS structure is used to report resource usage in the address space such as memory and IO.

Syntax

typedef struct _PEP_ACPI_EXTENDED_ADDRESS {
  PEP_ACPI_RESOURCE_TYPE  Type;
  PEP_ACPI_RESOURCE_FLAGS Flags;
  UCHAR                   ResourceFlags;
  UCHAR                   GeneralFlags;
  UCHAR                   TypeSpecificFlags;
  UCHAR                   RevisionId;
  UCHAR                   Reserved;
  ULONGLONG               Granularity;
  ULONGLONG               MinimumAddress;
  ULONGLONG               MaximumAddress;
  ULONGLONG               TranslationAddress;
  ULONGLONG               AddressLength;
  ULONGLONG               TypeAttribute;
  PUNICODE_STRING         DescriptorName;
} PEP_ACPI_EXTENDED_ADDRESS, *PPEP_ACPI_EXTENDED_ADDRESS;

Members

Type

A PEP_ACPI_RESOURCE_TYPE enumeration value describing this resource.

Flags

A PEP_ACPI_RESOURCE_FLAGS structure describing this resource.

ResourceFlags

Indicates the type of resource this structure describes.

Value Meaning
0
Indicates that this resource is a memory range.
1
Indicates that this resource is an IO range.
2
Indicates that this resource is a bus number range.
3-191
These values are reserved for future use.
192-255
These values are reserved for use by the hardware vendor.

GeneralFlags

A value containing the bit flags that are common to all resource types.

Bit(s) Meaning
0 - Consumer/Producer flag
When set, this indicates that the device consumes this resource.
1 - Decode type
When set, indicates that this bridge subtractively decodes the address. This applies to top level bridges only.

When not set, indicates that this bridge positively decodes this address.

2 - Minimum address fixed
When set, indicates that the minimum address is fixed.
3 - Max address fixed
When set, indicates that the maximum address is fixed.
4 to 7 - Reserved
These bits are reserved and must be set to zero.

TypeSpecificFlags

The value of this member is dependent on the value in ResourceFlags member. The flags for each resource type are described in the tables below.

Memory Resource (ResourceFlags = 0)

Bit(s) Meaning
0 - Write status
When set, indicates that this memory range is available for reading and writing. Otherwise, this indicates that this memory range is read-only.
1 to 2 - Memory attributes (MEM)
0 - Indicates the memory is non-cacheable.

1 - Indicates the memory is cacheable.

2 - Indicates the memory is cacheable and supports write combining.

3 - The memory is cacheable and prefetchable.

3 to 4 - Memory attributes (MTP)
These bits are only defined if this memory resource describes system RAM.

0 - Address range memory: This range is available RAM usable by the operating system.

1 - Address range reserved: This range of addresses is in use or reserved by the system and is not to be included in the allocatable memory pool of the operating system's memory manager.

2 - Address range ACPI: ACPI Reclaim Memory. This range is available RAM usable by the OS after it reads the ACPI tables.

3 - Address Range NVS: ACPI NVS Memory. This range of addresses is in use or reserved by the system and must not be used by the operating system. This range is required to be saved and restored across an NVS sleep.

5 - Memory to IO translation
0 - Type-static: This resource is memory on the primary and secondary sides of the bridge.

1 - Type-translation: This resource is memory on the secondary side of the bridge and IO on the primary side of the bridge.

6 to 7 - Reserved
These bits are reserved and must be set to zero.
 

IO Resource (ResourceFlags = 1)

Bit(s) Meaning
0 to 1 - Range
0 - Reserved.

1 - Non-ISA ranges only. This flag is for bridges on systems with multiple bridges. Setting this bit means the memory window specified in this descriptor is limited to the non-ISA IO addresses that fall within the specified window. The non-ISA IO ranges are: n100-n3FF, n500-n7FF, n900-nBFF, nD00-nFFF. This bit can only be set for bridges entirely configured through the ACPI namespace.

2 - ISA ranges only. This flag is for bridges on systems with multiple bridges. Setting this bit means the memory window specified in this descriptor is limited to the ISA IO addresses that fall within the specified window. The ISA IO ranges are: n000-n0FF, n400-n4FF, n800-n8FF, nC00-nCFF. This bit can only be set for bridges entirely configured through the ACPI namespace.

3 - The memory window covers the entire range

2 to 3 - Reserved
These bits are reserved and must be set to zero.
4 - IO to memory translation
0 - Type-static: This resource is IO on the primary and secondary sides of the bridge.

1 - Type-translation: This resource is IO on the secondary side of the bridge and memory on the primary side of the bridge.

5 - Sparse translation
This bit is only meaningful if bit 4 (IO to memory translation) is set.

0 - Dense translation: The primary-side memory address of any specific IO port within the secondary-side range can be found using the following function.

address = port + TranslationAddress

1 - Sparse translation: The primary-side memory address of any specific IO port within the secondary-side range can be found using the following function.

address = (((port & 0xFFFc) << 10) || (port & 0xFFF)) + TranslationAddress

In the address used to access the IO port, bits 2 to 11 must be identical to bits 12 to 21, this gives four bytes of IO ports on each 4 KB page.

6 to 7 - Reserved
These bits are reserved and must be set to zero.
 

Bus Number Range Resource (ResourceFlags = 2)

Bit(s) Meaning
0 to 7 - Reserved
These bits are reserved and must be set to zero.

RevisionId

Indicates the revision of the extended address space descriptor detailed by this structure. For ACPI 3.0, this value is 1.

Reserved

Granularity

A bit mask indicating which bits have been decoded.

MinimumAddress

The minimum starting address. For bridges that translate addresses, this is the address space on the secondary side of the bridge.

MaximumAddress

The maximum starting address. For bridges that translate addresses, this is the address space on the secondary side of the bridge.

TranslationAddress

For bridges that translate addresses across the bridge, this is the address on the primary side.

AddressLength

The address length.

TypeAttribute

Indicates attributes that are specific to the resource type that is specified in the ResourceFlags member. If ResourceFlags is zero, this value is zero, otherwise the meaning of the value can be found in the UEFI Specification in the section titled GetMemoryMap().

DescriptorName

The name of this resource descriptor.

Requirements

Requirement Value
Minimum supported client Supported starting with Windows 10.
Header pepfx.h (include Pep_x.h)