Intel Extensible Firmware Interface - Manual (Page 456)

Extensible Firmware Interface Specification
12-38 12/01/02 Version 1.10
ResourceLength A pointer to the length of the resource range to be modified by the
attributes specified by
Attributes . On return,
*ResourceLength will be set the actual length of the resource
range. Not all resources can be set to a byte boundary, so the
actual length may differ from the one passed in by the caller. This
parameter is only used if the
MEMORY_WRITE_COMBINE bit, the
MEMORY_CACHED bit, or the MEMORY_DISABLE bit of
Attributes is set. Otherwise, it is ignored, and may be NULL .
Description
The SetAttributes() function sets the attributes specified in Attributes for the PCI root
bridge on the resource range specified by ResourceBase and ResourceLength . 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 ResourceBase and
ResourceLength . 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 root bridge, then the actual resource range is returned in
ResourceBase and ResourceLength , and EFI_SUCCESS is returned.
If the attributes specified by Attributes are not supported by the PCI root bridge, then
EFI_UNSUPPORTED is returned. The set of supported attributes for a PCI root bridge can be
found by calling GetAttributes() .
If either ResourceBase or ResourceLength are NULL , and a resource range is required for
the attributes specified in Attributes , then EFI_INVALID_PARAMETER is returned.
If more than one resource range is required for the set of attributes specified by Attributes ,
then EFI_INVALID_PARAMETER is returned.
If there are not enough resources available to set the attributes, then EFI_OUT_OF_RESOURCES
is returned.