+ This function is invoked when the PXE Base Code Protocol is about to transmit, has received,\r
+ or is waiting to receive a packet. Parameters Function and Received specify the type of event.\r
+ Parameters PacketLen and Packet specify the packet that generated the event. If these fields\r
+ are zero and NULL respectively, then this is a status update callback. If the operation specified\r
+ by Function is to continue, then CALLBACK_STATUS_CONTINUE should be returned. If the operation\r
+ specified by Function should be aborted, then CALLBACK_STATUS_ABORT should be returned. Due to\r
+ the polling nature of UEFI device drivers, a callback function should not execute for more than 5 ms.\r
+ The SetParameters() function must be called after a Callback Protocol is installed to enable the\r
+ use of callbacks.\r
+ \r
+ @param This The pointer to the EFI_PXE_BASE_CODE_CALLBACK_PROTOCOL instance.\r