Intel Extensible Firmware Interface, Specification

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PXE Base Code Protocol
Version 1.02 12/12/00 275
Related Definitions
//*******************************************************
// EFI_PXE_BASE_CODE_CALLBACK_STATUS
//*******************************************************
typedef enum {
EFI_PXE_BASE_CODE_CALLBACK_STATUS_FIRST,
EFI_PXE_BASE_CODE_CALLBACK_STATUS_CONTINUE,
EFI_PXE_BASE_CODE_CALLBACK_STATUS_ABORT,
EFI_PXE_BASE_CODE_CALLBACK_STATUS_LAST
} EFI_PXE_BASE_CODE_CALLBACK_STATUS;
//*******************************************************
// 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.