Intel Extensible Firmware Interface - Manual (Page 918)

Extensible Firmware Interface Specification
E-52 12/01/02 Version 1.10
// Supported loopback options. This field can be one or a
// combination of more than one constants defined as
// PXE_LOOPBACK_xxxxx #defines below. This value indicates
// the ability of UNDI to change/control the loopback modes
// of the NIC
PXE_UINT8 SupportedLoopBackModes;
} PXE_DB_GET_INIT_INFO;
#pragma pack()
#define PXE_MAX_TXRX_UNIT_ETHER 1500
#define PXE_HWADDR_LEN_ETHER 0x0006
#define PXE_DUPLEX_AUTO_DETECT_SUPPORTED 1
define PXE_DUPLEX_FORCE_FULL_SUPPORTED 2
#define PXE_DUPLEX_FORCE_HALF_SUPPORTED 4
#define PXE_LOOPBACK_INTERNAL_SUPPORTED 1
#define PXE_LOOPBACK_EXTERNAL_SUPPORTED 2