Intel Extensible Firmware Interface - Manual (Page 674)

Extensible Firmware Interface Specification
15-68 12/01/02 Version 1.10
//*******************************************************
// EFI_PXE_BASE_CODE_FUNCTION
//*******************************************************
typedef enum {
EFI_PXE_BASE_CODE_FUNCTION_FIRST,
EFI_PXE_BASE_CODE_FUNCTION_DHCP,
EFI_PXE_BASE_CODE_FUNCTION_DISCOVER,
EFI_PXE_BASE_CODE_FUNCTION_MTFTP,
EFI_PXE_BASE_CODE_FUNCTION_UDP_WRITE,
EFI_PXE_BASE_CODE_FUNCTION_UDP_READ,
EFI_PXE_BASE_CODE_FUNCTION_ARP,
EFI_PXE_BASE_CODE_FUNCTION_IGMP,
EFI_PXE_BASE_CODE_PXE_FUNCTION_LAST
} EFI_PXE_BASE_CODE_FUNCTION;
Description
This function is invoked when the PXE Base Code Protocol is about to transmit, has received, or is
waiting to receive a packet. Parameters
Function and Received specify the type of event.
Parameters PacketLen and Packet specify the packet that generated the event. If these fields
are zero and NULL respectively, then this is a status update callback. If the operation specified by
Function is to continue, then CALLBACK_STATUS_CONTINUE should be returned. If the
operation specified by Function should be aborted, then CALLBACK_STATUS_ABORT should
be returned. Due to the polling nature of EFI device drivers, a callback function should not execute
for more than 5 ms.
The EFI_PXE_BASE_CODE.SetParameters() function must be called after a Callback
Protocol is installed to enable the use of callbacks.