Intel Extensible Firmware Interface, Specification

Page: 63 / 494

Services
Version 1.02 12/12/00 45
3.2.1 AllocatePages()
Summary
Allocates memory pages from the system.
Prototype
EFI_STATUS
AllocatePages(
IN EFI_ALLOCATE_TYPE Type,
IN EFI_MEMORY_TYPE MemoryType,
IN UINTN Pages,
IN OUT EFI_PHYSICAL_ADDRESS * Memory
);
Parameters
Type
The type of allocation to perform. See “Related Definitions”.
MemoryType
The type of memory to allocate. The only types allowed are
EfiLoaderCode, EfiLoaderData,
EfiRuntimeServicesCode, EfiRuntimeServicesData,
EfiBootServicesCode, EfiBootServicesData,
EfiACPIReclaimMemory,
and
EfiACPIMemoryNVS
. Normal
allocations (that is, allocations by any EFI application) are of type
EfiLoaderData
. See “Related Definitions”, Table 3-5, and
Table 3-6.
Pages
The number of contiguous 4KB pages to allocate.
Memory
Pointer to a physical address. On input, the way in which the address is
used depends on the value of
Type
. See “Description” for more
information. On output the address is set to the base of the page range
that was allocated. See “Related Definitions”.