audk/MdeModulePkg/Universal/Network/SnpDxe/WaitForPacket.c

/** @file
    Event handler to check for available packet.

Copyright (c) 2004 - 2008, Intel Corporation. <BR> 
All rights reserved. This program and the accompanying materials are licensed 
and made available under the terms and conditions of the BSD License which 
accompanies this distribution. The full text of the license may be found at 
http://opensource.org/licenses/bsd-license.php 

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#include "Snp.h"


/**
  Nofication call back function for WaitForPacket event.

  @param  Event       EFI Event.
  @param  SnpPtr      Pointer to SNP_DRIVER structure.

**/
VOID
EFIAPI
SnpWaitForPacketNotify (
  EFI_EVENT Event,
  VOID      *SnpPtr
  )
{
  PXE_DB_GET_STATUS PxeDbGetStatus;

  //
  // Do nothing if either parameter is a NULL pointer.
  //
  if (Event == NULL || SnpPtr == NULL) {
    return ;
  }
  //
  // Do nothing if the SNP interface is not initialized.
  //
  switch (((SNP_DRIVER *) SnpPtr)->Mode.State) {
  case EfiSimpleNetworkInitialized:
    break;

  case EfiSimpleNetworkStopped:
  case EfiSimpleNetworkStarted:
  default:
    return ;
  }
  //
  // Fill in CDB for UNDI GetStatus().
  //
  ((SNP_DRIVER *) SnpPtr)->Cdb.OpCode     = PXE_OPCODE_GET_STATUS;
  ((SNP_DRIVER *) SnpPtr)->Cdb.OpFlags    = 0;
  ((SNP_DRIVER *) SnpPtr)->Cdb.CPBsize    = PXE_CPBSIZE_NOT_USED;
  ((SNP_DRIVER *) SnpPtr)->Cdb.CPBaddr    = PXE_CPBADDR_NOT_USED;
  ((SNP_DRIVER *) SnpPtr)->Cdb.DBsize     = sizeof (UINT32) * 2;
  ((SNP_DRIVER *) SnpPtr)->Cdb.DBaddr     = (UINT64)(UINTN) (((SNP_DRIVER *) SnpPtr)->Db);
  ((SNP_DRIVER *) SnpPtr)->Cdb.StatCode   = PXE_STATCODE_INITIALIZE;
  ((SNP_DRIVER *) SnpPtr)->Cdb.StatFlags  = PXE_STATFLAGS_INITIALIZE;
  ((SNP_DRIVER *) SnpPtr)->Cdb.IFnum      = ((SNP_DRIVER *) SnpPtr)->IfNum;
  ((SNP_DRIVER *) SnpPtr)->Cdb.Control    = PXE_CONTROL_LAST_CDB_IN_LIST;

  //
  // Clear contents of DB buffer.
  //
  ZeroMem (((SNP_DRIVER *) SnpPtr)->Db, sizeof (UINT32) * 2);

  //
  // Issue UNDI command and check result.
  //
  (*((SNP_DRIVER *) SnpPtr)->IssueUndi32Command) ((UINT64)(UINTN) &((SNP_DRIVER *) SnpPtr)->Cdb);

  if (((SNP_DRIVER *) SnpPtr)->Cdb.StatCode != EFI_SUCCESS) {
    return ;
  }
  //
  // We might have a packet.  Check the receive length and signal
  // the event if the length is not zero.
  //
  CopyMem (
    &PxeDbGetStatus,
    ((SNP_DRIVER *) SnpPtr)->Db,
    sizeof (UINT32) * 2
    );

  if (PxeDbGetStatus.RxFrameLen != 0) {
    gBS->SignalEvent (Event);
  }
}

/* eof - WaitForPacket.c */