Intel Extensible Firmware Interface - Manual (Page 48)

Extensible Firmware Interface Specification
2-8 12/01/02 Version 1.10
Table 2-2. Common EFI Data Types (continued)
Mnemonic Description
INT32 4-byte signed value.
UINT32 4-byte unsigned value.
INT64 8-byte signed value.
UINT64 8-byte unsigned value.
CHAR8 1-byte Character.
CHAR16 2-byte Character. Unless otherwise specified all strings are stored in the
UTF-16 encoding format as defined by Unicode 2.1 and ISO/IEC 10646 standards.
VOID Undeclared type.
EFI_GUID 128-bit buffer containing a unique identifier value. Unless otherwise specified,
aligned on a 64-bit boundary.
EFI_STATUS Status code. Type INTN.
EFI_HANDLE A collection of related interfaces. Type VOID *.
EFI_EVENT Handle to an event structure. Type VOID *.
EFI_LBA Logicalblock address. Type UINT64.
EFI_TPL Task priority level. Type UINTN.
EFI_MAC_ADDRESS 32-byte buffer containing a network Media Access Controladdress.
EFI_IPv4_ADDRESS 4-byte buffer. An IPv4 internet protocoladdress.
EFI_IPv6_ADDRESS 16-byte buffer. An IPv6 internet protocoladdress.
EFI_IP_ADDRESS 16-byte buffer aligned on a 4-byte boundary. An IPv4 or IPv6 internet protocol
address.
Element of a standard ANSI C enum type declaration. Type INTN.
Table 2-3. Modifiers for Common EFI Data Types
Mnemonic Description
IN Datum is passed to the function.
OUT Datum is returned from the function.
OPTIONAL Passing the datum to the function is optional, and a NULL may be
passed if the value is not supplied.
EFIAPI Defines the calling convention for EFI interfaces.