Intel Extensible Firmware Interface Specification page 409

G.3.3.3 PXE_VOID
The void type does not allocate storage. This type is used only to prototype functions that do not
return any information and/or do not take any parameters.
typedef void PXE_VOID;
G.3.3.4 PXE_UINT8
Unsigned 8-bit integer.
typedef unsigned char PXE_UINT8;
G.3.3.5 PXE_UINT16
Unsigned 16-bit integer.
typedef unsigned short PXE_UINT16;
G.3.3.6 PXE_UINT32
Unsigned 32-bit integer.
typedef unsigned PXE_UINT32;
G.3.3.7 PXE_UINT64
Unsigned 64-bit integer.
#if PXE_UINT64_SUPPORT != 0
typedef unsigned long PXE_UINT64;
#endif // PXE_UINT64_SUPPORT
If a 64-bit integer type is not available in the compiler being used, use this definition:
#if PXE_NO_UINT64_SUPPORT != 0
typedef PXE_UINT32 PXE_UINT64[2];
#endif // PXE_NO_UINT64_SUPPORT
G.3.3.8 PXE_UINTN
Unsigned integer that is the default word size used by the compiler. This needs to be at least a
32-bit unsigned integer.
typedef unsigned PXE_UINTN;
Version 1.02
32/64-bit UNDI Specification
12/12/00 391