Intel Extensible Firmware Interface - Manual (Page 940)

Extensible Firmware Interface Specification
E-74 12/01/02 Version 1.10
E.4.14 MCast IP To MAC
Translate a multicast IPv4 or IPv6 address to a multicast MAC address.
E.4.14.1 Issuing the Command
To issue a MCast IP To MAC command, create a CDB and fill it in as shown in the table below:
CDB Field How to initialize the CDB structure for a MCast IP To MAC command
OpCode PXE_OPCODE_MCAST_IP_TO_MAC
OpFlags Set as needed.
CPBsize sizeof(PXE_CPB_MCAST_IP_TO_MAC)
DBsize sizeof(PXE_DB_MCAST_IP_TO_MAC)
CPBaddr Address of PXE_CPB_MCAST_IP_TO_MAC structure.
Dbaddr Address of PXE_DB_MCAST_IP_TO_MAC structure.
StatCode PXE_STATCODE_INITIALIZE
StatFlags PXE_STATFLAGS_INITIALIZE
Ifnum A valid interface number from zero to !PXE.IFcnt .
Control Set as needed.
OpFlags
To convert a multicast IP address to a multicast MAC address the UNDI needs to know the format
of the IP address. Set one of these OpFlags to identify the format of the IP addresses in the CPB:
PXE_OPFLAGS_MCAST_IPV4_TO_MAC
PXE_OPFLAGS_MCAST_IPV6_TO_MAC
Preparing the CPB
Fill in an array of one or more multicast IP addresses. Be sure to set the CDB.CPBsize and
CDB.CPBaddr fields accordingly.
typedef struct s_pxe_cpb_mcast_ip_to_mac {
// Multicast IP address to be converted to multicast
// MAC address.
PXE_IP_ADDR IP[n];
} PXE_CPB_MCAST_IP_TO_MAC;