Intel Extensible Firmware Interface - Manual (Page 124)

Extensible Firmware Interface Specification
5-26 12/01/02 Version 1.10
Related Definitions
//*******************************************************
//EFI_MEMORY_DESCRIPTOR
//*******************************************************
typedef struct {
UINT32
Type;
EFI_PHYSICAL_ADDRESS PhysicalStart;
EFI_VIRTUAL_ADDRESS VirtualStart;
UINT64 NumberOfPages;
UINT64 Attribute;
} EFI_MEMORY_DESCRIPTOR;
Type Type of the memory region. Type EFI_MEMORY_TYPE is
defined in the AllocatePages() function description.
PhysicalStart Physical address of the first byte in the memory region. Physical
start must be aligned on a 4 KB boundary. Type
EFI_PHYSICAL_ADDRESS is defined in the
AllocatePages() function description.
VirtualStart Virtual address of the first byte in the memory region. Virtual start
must be aligned on a 4 KB boundary. Type
EFI_VIRTUAL_ADDRESS is defined in “Related Definitions.”
NumberOfPages Number of 4 KB pages in the memory region.
Attribute Attributes of the memory region that describe the bit mask of
capabilities for that memory region, and not necessarily the current
settings for that memory region. See the following “Memory
Attribute Definitions.”
//*******************************************************
// Memory Attribute Definitions
//*******************************************************
// These types can be “ORed” together as needed.
#define EFI_MEMORY_UC
0x0000000000000001
#define EFI_MEMORY_WC 0x0000000000000002
#define EFI_MEMORY_WT 0x0000000000000004
#define EFI_MEMORY_WB 0x0000000000000008
#define EFI_MEMORY_UCE 0x0000000000000010
#define EFI_MEMORY_WP 0x0000000000001000
#define EFI_MEMORY_RP 0x0000000000002000
#define EFI_MEMORY_XP 0x0000000000004000
#define EFI_MEMORY_RUNTIME 0x8000000000000000