Intel Extensible Firmware Interface - Manual (Page 507)

Protocols — PCI Bus Support
Version 1.10 12/01/02 12-89
EFI_PCI_IO_PROTOCOL.GetBarAttributes()
Summary
Gets the attributes that this PCI controller supports setting on a BAR using
SetBarAttributes() , and retrieves the list of resource descriptors for a BAR.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_PCI_IO_PROTOCOL_GET_BAR_ATTRIBUTES) (
IN EFI_PCI_IO_PROTOCOL
*This,
IN UINT8 BarIndex,
OUT UINT64 *Supports OPTIONAL,
OUT VOID **Resources OPTIONAL
);
Parameters
This A pointer to the EFI_PCI_IO_PROTOCOL instance. Type
EFI_PCI_IO_PROTOCOL is defined in Section 12.4.
BarIndex The BAR index of the standard PCI Configuration header to use as
the base address for resource range. The legal range for this field
is 0..5.
Supports A pointer to the mask of attributes that this PCI controller supports
setting for this BAR with
SetBarAttributes() . The list of
attributes is listed in Section 12.4. This is an optional parameter
that may be
NULL .
Resources A pointer to the ACPI 2.0 resource descriptors that describe the
current configuration of this BAR of the PCI controller. This
buffer is allocated for the caller with the Boot Service
AllocatePool() . It is the caller’s responsibility to free the
buffer with the Boot Service FreePool() . See “Related
Definitions” below for the ACPI 2.0 resource descriptors that may
be used. This is an optional parameter that may be
NULL .