Intel Extensible Firmware Interface - Manual (Page 772)

Extensible Firmware Interface Specification
18-12 12/01/02 Version 1.10
Allocation requests of Type AllocateMaxAddress will allocate any available range of pages
that satisfies the request that are below or equal to the value pointed to by HostAddress on
input. On success, the value pointed to by HostAddress contains the base of the range actually
allocated. If there are not enough consecutive available pages below the requested address, an error
is returned.
Allocation requests of Type AllocateAddress will allocate the pages at the address supplied
in the data pointed to by HostAddress . If the range is not available memory an error is returned.
Status Codes Returned
EFI_SUCCESS The requested memory pages were allocated.
EFI_OUT_OF_RESOURCES The memory pages could not be allocated.
EFI_INVALID_PARAMETER The requested memory type is invalid.
EFI_UNSUPPORTED The requested HostAddress is not supported on
this platform.