Intel Extensible Firmware Interface - Manual (Page 511)

Protocols — PCI Bus Support
Version 1.10 12/01/02 12-93
Description
The SetBarAttributes() function sets the attributes specified in Attributes for the PCI
controller on the resource range specified by BarIndex , Offset , and Length . Since the
granularity of setting these attributes may vary from resource type to resource type, and from
platform to platform, the actual resource range and the one passed in by the caller may differ. As a
result, this function may set the attributes specified by
Attributes on a larger resource range
than the caller requested. The actual range is returned in Offset and Length . The caller is
responsible for verifying that the actual range for which the attributes were set is acceptable.
If the attributes are set on the PCI controller, then the actual resource range is returned in Offset
and Length , and EFI_SUCCESS is returned. Many of the attribute types also require that the
state of the PCI Host Bus Controller and the state of any PCI to PCI bridges between the PCI Host
Bus Controller and the PCI Controller to be modified. This function will only return
EFI_SUCCESS is all of these state changes are made. The PCI Controller may support a
combination of attributes, but unless the PCI Host Bus Controller and the PCI to PCI bridges also
support that same combination of attributes, then this call will return an error.
If the attributes specified by Attributes , or the resource range specified by BarIndex ,
Offset , and Length are not supported by the PCI controller, then EFI_UNSUPPORTED is
returned. The set of supported attributes for the PCI controller can be found by calling
GetBarAttributes() .
If either Offset or Length is NULL then EFI_INVALID_PARAMETER is returned.
If there are not enough resources available to set the attributes, then EFI_OUT_OF_RESOURCES
is returned.
Status Codes Returned
EFI_SUCCESS The set of attributes specified by Attributes for the resource
range specified by BarIndex , Offset , and Length were
set on the PCI controller, and the actual resource range is returned
in
Offset and Length .
EFI_UNSUPPORTED The set of attributes specified by Attributes is not supported
by the PCI controller for the resource range specified by
BarIndex , Offset , and Length .
EFI_INVALID_PARAMETER Offset is NULL .
EFI_INVALID_PARAMETER Length is NULL .
EFI_OUT_OF_RESOURCES There are not enough resources to set the attributes on the
resource range specified by
BarIndex , Offset , and
Length .