[mirror_edk2.git] / NetworkPkg / UefiPxeBcDxe / PxeBcBoot.c

/** @file\r
  Boot functions implementation for UefiPxeBc Driver.\r
\r
  Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>\r
  (C) Copyright 2016 Hewlett Packard Enterprise Development LP<BR>\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "PxeBcImpl.h"\r
\r
/**\r
  Display the string of the boot item.\r
\r
  If the length of the boot item string beyond 70 Char, just display 70 Char.\r
\r
  @param[in]  Str           The pointer to the string.\r
  @param[in]  Len           The length of the string.\r
\r
**/\r
VOID\r
PxeBcDisplayBootItem (\r
  IN UINT8  *Str,\r
  IN UINT8  Len\r
  )\r
{\r
  UINT8  Tmp;\r
\r
  //\r
  // Cut off the chars behind 70th.\r
  //\r
  Len      = (UINT8)MIN (PXEBC_DISPLAY_MAX_LINE, Len);\r
  Tmp      = Str[Len];\r
  Str[Len] = 0;\r
  AsciiPrint ("%a \n", Str);\r
\r
  //\r
  // Restore the original 70th char.\r
  //\r
  Str[Len] = Tmp;\r
}\r
\r
/**\r
  Select and maintain the boot prompt if needed.\r
\r
  @param[in]  Private          Pointer to PxeBc private data.\r
\r
  @retval EFI_SUCCESS          Selected boot prompt done.\r
  @retval EFI_TIMEOUT          Selected boot prompt timed out.\r
  @retval EFI_NOT_FOUND        The proxy offer is not Pxe10.\r
  @retval EFI_ABORTED          User cancelled the operation.\r
  @retval EFI_NOT_READY        Reading the input key from the keyboard has not finish.\r
\r
**/\r
EFI_STATUS\r
PxeBcSelectBootPrompt (\r
  IN PXEBC_PRIVATE_DATA  *Private\r
  )\r
{\r
  PXEBC_DHCP_PACKET_CACHE  *Cache;\r
  PXEBC_VENDOR_OPTION      *VendorOpt;\r
  EFI_PXE_BASE_CODE_MODE   *Mode;\r
  EFI_EVENT                TimeoutEvent;\r
  EFI_EVENT                DescendEvent;\r
  EFI_INPUT_KEY            InputKey;\r
  EFI_STATUS               Status;\r
  UINT32                   OfferType;\r
  UINT8                    Timeout;\r
  UINT8                    *Prompt;\r
  UINT8                    PromptLen;\r
  INT32                    SecCol;\r
  INT32                    SecRow;\r
\r
  TimeoutEvent = NULL;\r
  DescendEvent = NULL;\r
  Mode         = Private->PxeBc.Mode;\r
  Cache        = Mode->ProxyOfferReceived ? &Private->ProxyOffer : &Private->DhcpAck;\r
  OfferType    = Mode->UsingIpv6 ? Cache->Dhcp6.OfferType : Cache->Dhcp4.OfferType;\r
\r
  //\r
  // Only DhcpPxe10 and ProxyPxe10 offer needs boot prompt.\r
  //\r
  if ((OfferType != PxeOfferTypeProxyPxe10) && (OfferType != PxeOfferTypeDhcpPxe10)) {\r
    return EFI_NOT_FOUND;\r
  }\r
\r
  //\r
  // There is no specified ProxyPxe10 for IPv6 in PXE and UEFI spec.\r
  //\r
  ASSERT (!Mode->UsingIpv6);\r
\r
  VendorOpt = &Cache->Dhcp4.VendorOpt;\r
  //\r
  // According to the PXE specification 2.1, Table 2-1 PXE DHCP Options,\r
  // we must not consider a boot prompt or boot menu if all of the following hold:\r
  //   - the PXE_DISCOVERY_CONTROL tag(6) is present inside the Vendor Options(43), and has bit 3 set\r
  //   - a boot file name has been presented in the initial DHCP or ProxyDHCP offer packet.\r
  //\r
  if (IS_DISABLE_PROMPT_MENU (VendorOpt->DiscoverCtrl) &&\r
      (Cache->Dhcp4.OptList[PXEBC_DHCP4_TAG_INDEX_BOOTFILE] != NULL))\r
  {\r
    return EFI_ABORTED;\r
  }\r
\r
  if (!IS_VALID_BOOT_PROMPT (VendorOpt->BitMap)) {\r
    return EFI_TIMEOUT;\r
  }\r
\r
  Timeout   = VendorOpt->MenuPrompt->Timeout;\r
  Prompt    = VendorOpt->MenuPrompt->Prompt;\r
  PromptLen = (UINT8)(VendorOpt->MenuPromptLen - 1);\r
\r
  //\r
  // The valid scope of Timeout refers to PXE2.1 spec.\r
  //\r
  if (Timeout == 0) {\r
    return EFI_TIMEOUT;\r
  }\r
\r
  if (Timeout == 255) {\r
    return EFI_SUCCESS;\r
  }\r
\r
  //\r
  // Create and start a timer as timeout event.\r
  //\r
  Status = gBS->CreateEvent (\r
                  EVT_TIMER,\r
                  TPL_CALLBACK,\r
                  NULL,\r
                  NULL,\r
                  &TimeoutEvent\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  Status = gBS->SetTimer (\r
                  TimeoutEvent,\r
                  TimerRelative,\r
                  MultU64x32 (Timeout, TICKS_PER_SECOND)\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    goto ON_EXIT;\r
  }\r
\r
  //\r
  // Create and start a periodic timer as descend event by second.\r
  //\r
  Status = gBS->CreateEvent (\r
                  EVT_TIMER,\r
                  TPL_CALLBACK,\r
                  NULL,\r
                  NULL,\r
                  &DescendEvent\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    goto ON_EXIT;\r
  }\r
\r
  Status = gBS->SetTimer (\r
                  DescendEvent,\r
                  TimerPeriodic,\r
                  TICKS_PER_SECOND\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    goto ON_EXIT;\r
  }\r
\r
  //\r
  // Display the boot item and cursor on the screen.\r
  //\r
  SecCol = gST->ConOut->Mode->CursorColumn;\r
  SecRow = gST->ConOut->Mode->CursorRow;\r
\r
  PxeBcDisplayBootItem (Prompt, PromptLen);\r
\r
  gST->ConOut->SetCursorPosition (gST->ConOut, SecCol + PromptLen, SecRow);\r
  AsciiPrint ("(%d) ", Timeout--);\r
\r
  Status = EFI_TIMEOUT;\r
  while (EFI_ERROR (gBS->CheckEvent (TimeoutEvent))) {\r
    if (!EFI_ERROR (gBS->CheckEvent (DescendEvent))) {\r
      gST->ConOut->SetCursorPosition (gST->ConOut, SecCol + PromptLen, SecRow);\r
      AsciiPrint ("(%d) ", Timeout--);\r
    }\r
\r
    if (gST->ConIn->ReadKeyStroke (gST->ConIn, &InputKey) == EFI_NOT_READY) {\r
      gBS->Stall (10 * TICKS_PER_MS);\r
      continue;\r
    }\r
\r
    //\r
    // Parse the input key by user.\r
    // If <F8> or <Ctrl> + <M> is pressed, return success to display the boot menu.\r
    //\r
    if (InputKey.ScanCode == 0) {\r
      switch (InputKey.UnicodeChar) {\r
        case CTRL ('c'):\r
          Status = EFI_ABORTED;\r
          break;\r
\r
        case CTRL ('m'):\r
        case 'm':\r
        case 'M':\r
          Status = EFI_SUCCESS;\r
          break;\r
\r
        default:\r
          continue;\r
      }\r
    } else {\r
      switch (InputKey.ScanCode) {\r
        case SCAN_F8:\r
          Status = EFI_SUCCESS;\r
          break;\r
\r
        case SCAN_ESC:\r
          Status = EFI_ABORTED;\r
          break;\r
\r
        default:\r
          continue;\r
      }\r
    }\r
\r
    break;\r
  }\r
\r
  //\r
  // Reset the cursor on the screen.\r
  //\r
  gST->ConOut->SetCursorPosition (gST->ConOut, 0, SecRow + 1);\r
\r
ON_EXIT:\r
  if (DescendEvent != NULL) {\r
    gBS->CloseEvent (DescendEvent);\r
  }\r
\r
  if (TimeoutEvent != NULL) {\r
    gBS->CloseEvent (TimeoutEvent);\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Select the boot menu by user's input.\r
\r
  @param[in]  Private         Pointer to PxeBc private data.\r
  @param[out] Type            The type of the menu.\r
  @param[in]  UseDefaultItem  Use default item or not.\r
\r
  @retval EFI_ABORTED     User cancel operation.\r
  @retval EFI_SUCCESS     Select the boot menu success.\r
  @retval EFI_NOT_READY   Read the input key from the keyboard has not finish.\r
\r
**/\r
EFI_STATUS\r
PxeBcSelectBootMenu (\r
  IN  PXEBC_PRIVATE_DATA  *Private,\r
  OUT UINT16              *Type,\r
  IN  BOOLEAN             UseDefaultItem\r
  )\r
{\r
  EFI_PXE_BASE_CODE_MODE   *Mode;\r
  PXEBC_DHCP_PACKET_CACHE  *Cache;\r
  PXEBC_VENDOR_OPTION      *VendorOpt;\r
  EFI_INPUT_KEY            InputKey;\r
  UINT32                   OfferType;\r
  UINT8                    MenuSize;\r
  UINT8                    MenuNum;\r
  INT32                    TopRow;\r
  UINT16                   Select;\r
  UINT16                   LastSelect;\r
  UINT8                    Index;\r
  BOOLEAN                  Finish;\r
  CHAR8                    Blank[PXEBC_DISPLAY_MAX_LINE];\r
  PXEBC_BOOT_MENU_ENTRY    *MenuItem;\r
  PXEBC_BOOT_MENU_ENTRY    *MenuArray[PXEBC_MENU_MAX_NUM];\r
\r
  Finish    = FALSE;\r
  Select    = 0;\r
  Index     = 0;\r
  *Type     = 0;\r
  Mode      = Private->PxeBc.Mode;\r
  Cache     = Mode->ProxyOfferReceived ? &Private->ProxyOffer : &Private->DhcpAck;\r
  OfferType = Mode->UsingIpv6 ? Cache->Dhcp6.OfferType : Cache->Dhcp4.OfferType;\r
\r
  //\r
  // There is no specified DhcpPxe10/ProxyPxe10 for IPv6 in PXE and UEFI spec.\r
  //\r
  ASSERT (!Mode->UsingIpv6);\r
  ASSERT (OfferType == PxeOfferTypeProxyPxe10 || OfferType == PxeOfferTypeDhcpPxe10);\r
\r
  VendorOpt = &Cache->Dhcp4.VendorOpt;\r
  if (!IS_VALID_BOOT_MENU (VendorOpt->BitMap)) {\r
    return EFI_SUCCESS;\r
  }\r
\r
  //\r
  // Display the boot menu on the screen.\r
  //\r
  SetMem (Blank, sizeof (Blank), ' ');\r
\r
  MenuSize = VendorOpt->BootMenuLen;\r
  MenuItem = VendorOpt->BootMenu;\r
\r
  if (MenuSize == 0) {\r
    return EFI_DEVICE_ERROR;\r
  }\r
\r
  while (MenuSize > 0 && Index < PXEBC_MENU_MAX_NUM) {\r
    ASSERT (MenuItem != NULL);\r
    MenuArray[Index] = MenuItem;\r
    MenuSize         = (UINT8)(MenuSize - (MenuItem->DescLen + 3));\r
    MenuItem         = (PXEBC_BOOT_MENU_ENTRY *)((UINT8 *)MenuItem + MenuItem->DescLen + 3);\r
    Index++;\r
  }\r
\r
  if (UseDefaultItem) {\r
    ASSERT (MenuArray[0] != NULL);\r
    CopyMem (Type, &MenuArray[0]->Type, sizeof (UINT16));\r
    *Type = NTOHS (*Type);\r
    return EFI_SUCCESS;\r
  }\r
\r
  MenuNum = Index;\r
\r
  for (Index = 0; Index < MenuNum; Index++) {\r
    ASSERT (MenuArray[Index] != NULL);\r
    PxeBcDisplayBootItem (MenuArray[Index]->DescStr, MenuArray[Index]->DescLen);\r
  }\r
\r
  TopRow = gST->ConOut->Mode->CursorRow - MenuNum;\r
\r
  //\r
  // Select the boot item by user in the boot menu.\r
  //\r
  do {\r
    //\r
    // Highlight selected row.\r
    //\r
    gST->ConOut->SetAttribute (gST->ConOut, EFI_TEXT_ATTR (EFI_BLACK, EFI_LIGHTGRAY));\r
    gST->ConOut->SetCursorPosition (gST->ConOut, 0, TopRow + Select);\r
    ASSERT (Select < PXEBC_MENU_MAX_NUM);\r
    ASSERT (MenuArray[Select] != NULL);\r
    Blank[MenuArray[Select]->DescLen] = 0;\r
    AsciiPrint ("%a\r", Blank);\r
    PxeBcDisplayBootItem (MenuArray[Select]->DescStr, MenuArray[Select]->DescLen);\r
    gST->ConOut->SetCursorPosition (gST->ConOut, 0, TopRow + MenuNum);\r
    LastSelect = Select;\r
\r
    while (gST->ConIn->ReadKeyStroke (gST->ConIn, &InputKey) == EFI_NOT_READY) {\r
      gBS->Stall (10 * TICKS_PER_MS);\r
    }\r
\r
    if (InputKey.ScanCode == 0) {\r
      switch (InputKey.UnicodeChar) {\r
        case CTRL ('c'):\r
          InputKey.ScanCode = SCAN_ESC;\r
          break;\r
\r
        case CTRL ('j'): /* linefeed */\r
        case CTRL ('m'): /* return */\r
          Finish = TRUE;\r
          break;\r
\r
        case CTRL ('i'): /* tab */\r
        case ' ':\r
        case 'd':\r
        case 'D':\r
          InputKey.ScanCode = SCAN_DOWN;\r
          break;\r
\r
        case CTRL ('h'): /* backspace */\r
        case 'u':\r
        case 'U':\r
          InputKey.ScanCode = SCAN_UP;\r
          break;\r
\r
        default:\r
          InputKey.ScanCode = 0;\r
      }\r
    }\r
\r
    switch (InputKey.ScanCode) {\r
      case SCAN_LEFT:\r
      case SCAN_UP:\r
        if (Select != 0) {\r
          Select--;\r
        }\r
\r
        break;\r
\r
      case SCAN_DOWN:\r
      case SCAN_RIGHT:\r
        if (++Select == MenuNum) {\r
          Select--;\r
        }\r
\r
        break;\r
\r
      case SCAN_PAGE_UP:\r
      case SCAN_HOME:\r
        Select = 0;\r
        break;\r
\r
      case SCAN_PAGE_DOWN:\r
      case SCAN_END:\r
        Select = (UINT16)(MenuNum - 1);\r
        break;\r
\r
      case SCAN_ESC:\r
        return EFI_ABORTED;\r
    }\r
\r
    //\r
    // Unhighlight the last selected row.\r
    //\r
    gST->ConOut->SetAttribute (gST->ConOut, EFI_TEXT_ATTR (EFI_LIGHTGRAY, EFI_BLACK));\r
    gST->ConOut->SetCursorPosition (gST->ConOut, 0, TopRow + LastSelect);\r
    ASSERT (LastSelect < PXEBC_MENU_MAX_NUM);\r
    ASSERT (MenuArray[LastSelect] != NULL);\r
    Blank[MenuArray[LastSelect]->DescLen] = 0;\r
    AsciiPrint ("%a\r", Blank);\r
    PxeBcDisplayBootItem (MenuArray[LastSelect]->DescStr, MenuArray[LastSelect]->DescLen);\r
    gST->ConOut->SetCursorPosition (gST->ConOut, 0, TopRow + MenuNum);\r
  } while (!Finish);\r
\r
  //\r
  // Swap the byte order.\r
  //\r
  ASSERT (Select < PXEBC_MENU_MAX_NUM);\r
  ASSERT (MenuArray[Select] != NULL);\r
  CopyMem (Type, &MenuArray[Select]->Type, sizeof (UINT16));\r
  *Type = NTOHS (*Type);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Parse out the boot information from the last Dhcp4 reply packet.\r
\r
  @param[in, out] Private      Pointer to PxeBc private data.\r
  @param[out]     BufferSize   Size of the boot file to be downloaded.\r
\r
  @retval EFI_SUCCESS          Successfully parsed out all the boot information.\r
  @retval Others               Failed to parse out the boot information.\r
\r
**/\r
EFI_STATUS\r
PxeBcDhcp4BootInfo (\r
  IN OUT PXEBC_PRIVATE_DATA  *Private,\r
  OUT UINT64                 *BufferSize\r
  )\r
{\r
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;\r
  EFI_PXE_BASE_CODE_MODE      *Mode;\r
  EFI_STATUS                  Status;\r
  PXEBC_DHCP4_PACKET_CACHE    *Cache4;\r
  UINT16                      Value;\r
  PXEBC_VENDOR_OPTION         *VendorOpt;\r
  PXEBC_BOOT_SVR_ENTRY        *Entry;\r
\r
  PxeBc       = &Private->PxeBc;\r
  Mode        = PxeBc->Mode;\r
  Status      = EFI_SUCCESS;\r
  *BufferSize = 0;\r
\r
  //\r
  // Get the last received Dhcp4 reply packet.\r
  //\r
  if (Mode->PxeReplyReceived) {\r
    Cache4 = &Private->PxeReply.Dhcp4;\r
  } else if (Mode->ProxyOfferReceived) {\r
    Cache4 = &Private->ProxyOffer.Dhcp4;\r
  } else {\r
    Cache4 = &Private->DhcpAck.Dhcp4;\r
  }\r
\r
  if (Cache4->OptList[PXEBC_DHCP4_TAG_INDEX_BOOTFILE] == NULL) {\r
    //\r
    // This should never happen in a correctly configured DHCP / PXE\r
    // environment. One misconfiguration that can cause it is two DHCP servers\r
    // mistakenly running on the same network segment at the same time, and\r
    // racing each other in answering DHCP requests. Thus, the DHCP packets\r
    // that the edk2 PXE client considers "belonging together" may actually be\r
    // entirely independent, coming from two (competing) DHCP servers.\r
    //\r
    // Try to deal with this gracefully. Note that this check is not\r
    // comprehensive, as we don't try to identify all such errors.\r
    //\r
    return EFI_PROTOCOL_ERROR;\r
  }\r
\r
  //\r
  // Parse the boot server address.\r
  // If prompt/discover is disabled, get the first boot server from the boot servers list.\r
  // Otherwise, parse the boot server Ipv4 address from next server address field in DHCP header.\r
  // If all these fields are not available, use option 54 instead.\r
  //\r
  VendorOpt = &Cache4->VendorOpt;\r
  if (IS_DISABLE_PROMPT_MENU (VendorOpt->DiscoverCtrl) && IS_VALID_BOOT_SERVERS (VendorOpt->BitMap)) {\r
    Entry = VendorOpt->BootSvr;\r
    if ((VendorOpt->BootSvrLen >= sizeof (PXEBC_BOOT_SVR_ENTRY)) && (Entry->IpCnt > 0)) {\r
      CopyMem (\r
        &Private->ServerIp,\r
        &Entry->IpAddr[0],\r
        sizeof (EFI_IPv4_ADDRESS)\r
        );\r
    }\r
  }\r
\r
  if (Private->ServerIp.Addr[0] == 0) {\r
    //\r
    // ServerIp.Addr[0] equals zero means we failed to get IP address from boot server list.\r
    // Try to use next server address field.\r
    //\r
    CopyMem (\r
      &Private->ServerIp,\r
      &Cache4->Packet.Offer.Dhcp4.Header.ServerAddr,\r
      sizeof (EFI_IPv4_ADDRESS)\r
      );\r
  }\r
\r
  if (Private->ServerIp.Addr[0] == 0) {\r
    //\r
    // Still failed , use the IP address from option 54.\r
    //\r
    CopyMem (\r
      &Private->ServerIp,\r
      Cache4->OptList[PXEBC_DHCP4_TAG_INDEX_SERVER_ID]->Data,\r
      sizeof (EFI_IPv4_ADDRESS)\r
      );\r
  }\r
\r
  //\r
  // Parse the boot file name by option.\r
  //\r
  Private->BootFileName = Cache4->OptList[PXEBC_DHCP4_TAG_INDEX_BOOTFILE]->Data;\r
\r
  if (Cache4->OptList[PXEBC_DHCP4_TAG_INDEX_BOOTFILE_LEN] != NULL) {\r
    //\r
    // Parse the boot file size by option.\r
    //\r
    CopyMem (&Value, Cache4->OptList[PXEBC_DHCP4_TAG_INDEX_BOOTFILE_LEN]->Data, sizeof (Value));\r
    Value = NTOHS (Value);\r
    //\r
    // The field of boot file size is 512 bytes in unit.\r
    //\r
    *BufferSize = 512 * Value;\r
  } else {\r
    //\r
    // Get the bootfile size by tftp command if no option available.\r
    //\r
    Status = PxeBc->Mtftp (\r
                      PxeBc,\r
                      EFI_PXE_BASE_CODE_TFTP_GET_FILE_SIZE,\r
                      NULL,\r
                      FALSE,\r
                      BufferSize,\r
                      &Private->BlockSize,\r
                      &Private->ServerIp,\r
                      Private->BootFileName,\r
                      NULL,\r
                      FALSE\r
                      );\r
  }\r
\r
  //\r
  // Save the value of boot file size.\r
  //\r
  Private->BootFileSize = (UINTN)*BufferSize;\r
\r
  //\r
  // Display all the information: boot server address, boot file name and boot file size.\r
  //\r
  AsciiPrint ("\n  Server IP address is ");\r
  PxeBcShowIp4Addr (&Private->ServerIp.v4);\r
  AsciiPrint ("\n  NBP filename is %a", Private->BootFileName);\r
  AsciiPrint ("\n  NBP filesize is %d Bytes", Private->BootFileSize);\r
\r
  return Status;\r
}\r
\r
/**\r
  Parse out the boot information from the last Dhcp6 reply packet.\r
\r
  @param[in, out] Private      Pointer to PxeBc private data.\r
  @param[out]     BufferSize   Size of the boot file to be downloaded.\r
\r
  @retval EFI_SUCCESS          Successfully parsed out all the boot information.\r
  @retval EFI_BUFFER_TOO_SMALL\r
  @retval Others               Failed to parse out the boot information.\r
\r
**/\r
EFI_STATUS\r
PxeBcDhcp6BootInfo (\r
  IN OUT PXEBC_PRIVATE_DATA  *Private,\r
  OUT UINT64                 *BufferSize\r
  )\r
{\r
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;\r
  EFI_PXE_BASE_CODE_MODE      *Mode;\r
  EFI_STATUS                  Status;\r
  PXEBC_DHCP6_PACKET_CACHE    *Cache6;\r
  UINT16                      Value;\r
\r
  PxeBc       = &Private->PxeBc;\r
  Mode        = PxeBc->Mode;\r
  Status      = EFI_SUCCESS;\r
  *BufferSize = 0;\r
\r
  //\r
  // Get the last received Dhcp6 reply packet.\r
  //\r
  if (Mode->PxeReplyReceived) {\r
    Cache6 = &Private->PxeReply.Dhcp6;\r
  } else if (Mode->ProxyOfferReceived) {\r
    Cache6 = &Private->ProxyOffer.Dhcp6;\r
  } else {\r
    Cache6 = &Private->DhcpAck.Dhcp6;\r
  }\r
\r
  if (Cache6->OptList[PXEBC_DHCP6_IDX_BOOT_FILE_URL] == NULL) {\r
    //\r
    // This should never happen in a correctly configured DHCP / PXE\r
    // environment. One misconfiguration that can cause it is two DHCP servers\r
    // mistakenly running on the same network segment at the same time, and\r
    // racing each other in answering DHCP requests. Thus, the DHCP packets\r
    // that the edk2 PXE client considers "belonging together" may actually be\r
    // entirely independent, coming from two (competing) DHCP servers.\r
    //\r
    // Try to deal with this gracefully. Note that this check is not\r
    // comprehensive, as we don't try to identify all such errors.\r
    //\r
    return EFI_PROTOCOL_ERROR;\r
  }\r
\r
  //\r
  // Set the station address to IP layer.\r
  //\r
  Status = PxeBcSetIp6Address (Private);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Parse (m)tftp server ip address and bootfile name.\r
  //\r
  Status = PxeBcExtractBootFileUrl (\r
             Private,\r
             &Private->BootFileName,\r
             &Private->ServerIp.v6,\r
             (CHAR8 *)(Cache6->OptList[PXEBC_DHCP6_IDX_BOOT_FILE_URL]->Data),\r
             NTOHS (Cache6->OptList[PXEBC_DHCP6_IDX_BOOT_FILE_URL]->OpLen)\r
             );\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Parse the value of boot file size.\r
  //\r
  if (Cache6->OptList[PXEBC_DHCP6_IDX_BOOT_FILE_PARAM] != NULL) {\r
    //\r
    // Parse it out if have the boot file parameter option.\r
    //\r
    Status = PxeBcExtractBootFileParam ((CHAR8 *)Cache6->OptList[PXEBC_DHCP6_IDX_BOOT_FILE_PARAM]->Data, &Value);\r
    if (EFI_ERROR (Status)) {\r
      return Status;\r
    }\r
\r
    //\r
    // The field of boot file size is 512 bytes in unit.\r
    //\r
    *BufferSize = 512 * Value;\r
  } else {\r
    //\r
    // Send get file size command by tftp if option unavailable.\r
    //\r
    Status = PxeBc->Mtftp (\r
                      PxeBc,\r
                      EFI_PXE_BASE_CODE_TFTP_GET_FILE_SIZE,\r
                      NULL,\r
                      FALSE,\r
                      BufferSize,\r
                      &Private->BlockSize,\r
                      &Private->ServerIp,\r
                      Private->BootFileName,\r
                      NULL,\r
                      FALSE\r
                      );\r
  }\r
\r
  //\r
  // Save the value of boot file size.\r
  //\r
  Private->BootFileSize = (UINTN)*BufferSize;\r
\r
  //\r
  // Display all the information: boot server address, boot file name and boot file size.\r
  //\r
  AsciiPrint ("\n  Server IP address is ");\r
  PxeBcShowIp6Addr (&Private->ServerIp.v6);\r
  AsciiPrint ("\n  NBP filename is %a", Private->BootFileName);\r
  AsciiPrint ("\n  NBP filesize is %d Bytes", Private->BootFileSize);\r
\r
  return Status;\r
}\r
\r
/**\r
  Extract the discover information and boot server entry from the\r
  cached packets if unspecified.\r
\r
  @param[in]      Private      Pointer to PxeBc private data.\r
  @param[in]      Type         The type of bootstrap to perform.\r
  @param[in, out] DiscoverInfo Pointer to EFI_PXE_BASE_CODE_DISCOVER_INFO.\r
  @param[out]     BootEntry    Pointer to PXEBC_BOOT_SVR_ENTRY.\r
  @param[out]     SrvList      Pointer to EFI_PXE_BASE_CODE_SRVLIST.\r
\r
  @retval EFI_SUCCESS       Successfully extracted the information.\r
  @retval EFI_DEVICE_ERROR  Failed to extract the information.\r
\r
**/\r
EFI_STATUS\r
PxeBcExtractDiscoverInfo (\r
  IN     PXEBC_PRIVATE_DATA               *Private,\r
  IN     UINT16                           Type,\r
  IN OUT EFI_PXE_BASE_CODE_DISCOVER_INFO  **DiscoverInfo,\r
  OUT PXEBC_BOOT_SVR_ENTRY                **BootEntry,\r
  OUT EFI_PXE_BASE_CODE_SRVLIST           **SrvList\r
  )\r
{\r
  EFI_PXE_BASE_CODE_MODE           *Mode;\r
  PXEBC_DHCP4_PACKET_CACHE         *Cache4;\r
  PXEBC_VENDOR_OPTION              *VendorOpt;\r
  PXEBC_BOOT_SVR_ENTRY             *Entry;\r
  BOOLEAN                          IsFound;\r
  EFI_PXE_BASE_CODE_DISCOVER_INFO  *Info;\r
  UINT16                           Index;\r
\r
  Mode = Private->PxeBc.Mode;\r
  Info = *DiscoverInfo;\r
\r
  if (Mode->UsingIpv6) {\r
    Info->IpCnt    = 1;\r
    Info->UseUCast = TRUE;\r
\r
    Info->SrvList[0].Type              = Type;\r
    Info->SrvList[0].AcceptAnyResponse = FALSE;\r
\r
    //\r
    // There is no vendor options specified in DHCPv6, so take BootFileUrl in the last cached packet.\r
    //\r
    CopyMem (&Info->SrvList[0].IpAddr, &Private->ServerIp, sizeof (EFI_IP_ADDRESS));\r
\r
    *SrvList = Info->SrvList;\r
  } else {\r
    Entry     = NULL;\r
    IsFound   = FALSE;\r
    Cache4    = (Mode->ProxyOfferReceived) ? &Private->ProxyOffer.Dhcp4 : &Private->DhcpAck.Dhcp4;\r
    VendorOpt = &Cache4->VendorOpt;\r
\r
    if (!Mode->DhcpAckReceived || !IS_VALID_DISCOVER_VENDOR_OPTION (VendorOpt->BitMap)) {\r
      //\r
      // Address is not acquired or no discovery options.\r
      //\r
      return EFI_INVALID_PARAMETER;\r
    }\r
\r
    //\r
    // Parse the boot server entry from the vendor option in the last cached packet.\r
    //\r
    Info->UseMCast    = (BOOLEAN) !IS_DISABLE_MCAST_DISCOVER (VendorOpt->DiscoverCtrl);\r
    Info->UseBCast    = (BOOLEAN) !IS_DISABLE_BCAST_DISCOVER (VendorOpt->DiscoverCtrl);\r
    Info->MustUseList = (BOOLEAN)IS_ENABLE_USE_SERVER_LIST (VendorOpt->DiscoverCtrl);\r
    Info->UseUCast    = (BOOLEAN)IS_VALID_BOOT_SERVERS (VendorOpt->BitMap);\r
\r
    if (Info->UseMCast) {\r
      //\r
      // Get the multicast discover ip address from vendor option if has.\r
      //\r
      CopyMem (&Info->ServerMCastIp.v4, &VendorOpt->DiscoverMcastIp, sizeof (EFI_IPv4_ADDRESS));\r
    }\r
\r
    Info->IpCnt = 0;\r
\r
    if (Info->UseUCast) {\r
      Entry = VendorOpt->BootSvr;\r
\r
      while (((UINT8)(Entry - VendorOpt->BootSvr)) < VendorOpt->BootSvrLen) {\r
        if (Entry->Type == HTONS (Type)) {\r
          IsFound = TRUE;\r
          break;\r
        }\r
\r
        Entry = GET_NEXT_BOOT_SVR_ENTRY (Entry);\r
      }\r
\r
      if (!IsFound) {\r
        return EFI_DEVICE_ERROR;\r
      }\r
\r
      Info->IpCnt = Entry->IpCnt;\r
      if (Info->IpCnt >= 1) {\r
        *DiscoverInfo = AllocatePool (sizeof (*Info) + (Info->IpCnt - 1) * sizeof (**SrvList));\r
        if (*DiscoverInfo == NULL) {\r
          return EFI_OUT_OF_RESOURCES;\r
        }\r
\r
        CopyMem (*DiscoverInfo, Info, sizeof (*Info));\r
        Info = *DiscoverInfo;\r
      }\r
\r
      for (Index = 0; Index < Info->IpCnt; Index++) {\r
        CopyMem (&Info->SrvList[Index].IpAddr, &Entry->IpAddr[Index], sizeof (EFI_IPv4_ADDRESS));\r
        Info->SrvList[Index].AcceptAnyResponse = !Info->MustUseList;\r
        Info->SrvList[Index].Type              = NTOHS (Entry->Type);\r
      }\r
    }\r
\r
    *BootEntry = Entry;\r
    *SrvList   = Info->SrvList;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Build the discover packet and send out for boot server.\r
\r
  @param[in]  Private               Pointer to PxeBc private data.\r
  @param[in]  Type                  PxeBc option boot item type.\r
  @param[in]  Layer                 Pointer to option boot item layer.\r
  @param[in]  UseBis                Use BIS or not.\r
  @param[in]  DestIp                Pointer to the destination address.\r
  @param[in]  IpCount               The count of the server address.\r
  @param[in]  SrvList               Pointer to the server address list.\r
\r
  @retval     EFI_SUCCESS           Successfully discovered boot file.\r
  @retval     EFI_OUT_OF_RESOURCES  Failed to allocate resource.\r
  @retval     EFI_NOT_FOUND         Can't get the PXE reply packet.\r
  @retval     Others                Failed to discover boot file.\r
\r
**/\r
EFI_STATUS\r
PxeBcDiscoverBootServer (\r
  IN  PXEBC_PRIVATE_DATA         *Private,\r
  IN  UINT16                     Type,\r
  IN  UINT16                     *Layer,\r
  IN  BOOLEAN                    UseBis,\r
  IN  EFI_IP_ADDRESS             *DestIp,\r
  IN  UINT16                     IpCount,\r
  IN  EFI_PXE_BASE_CODE_SRVLIST  *SrvList\r
  )\r
{\r
  if (Private->PxeBc.Mode->UsingIpv6) {\r
    return PxeBcDhcp6Discover (\r
             Private,\r
             Type,\r
             Layer,\r
             UseBis,\r
             DestIp\r
             );\r
  } else {\r
    return PxeBcDhcp4Discover (\r
             Private,\r
             Type,\r
             Layer,\r
             UseBis,\r
             DestIp,\r
             IpCount,\r
             SrvList\r
             );\r
  }\r
}\r
\r
/**\r
  Discover all the boot information for boot file.\r
\r
  @param[in, out] Private      Pointer to PxeBc private data.\r
  @param[out]     BufferSize   Size of the boot file to be downloaded.\r
\r
  @retval EFI_SUCCESS          Successfully obtained all the boot information .\r
  @retval EFI_BUFFER_TOO_SMALL The buffer size is not enough for boot file.\r
  @retval EFI_ABORTED          User cancel current operation.\r
  @retval Others               Failed to parse out the boot information.\r
\r
**/\r
EFI_STATUS\r
PxeBcDiscoverBootFile (\r
  IN OUT PXEBC_PRIVATE_DATA  *Private,\r
  OUT UINT64                 *BufferSize\r
  )\r
{\r
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;\r
  EFI_PXE_BASE_CODE_MODE      *Mode;\r
  EFI_STATUS                  Status;\r
  UINT16                      Type;\r
  UINT16                      Layer;\r
  BOOLEAN                     UseBis;\r
\r
  PxeBc = &Private->PxeBc;\r
  Mode  = PxeBc->Mode;\r
  Type  = EFI_PXE_BASE_CODE_BOOT_TYPE_BOOTSTRAP;\r
  Layer = EFI_PXE_BASE_CODE_BOOT_LAYER_INITIAL;\r
\r
  //\r
  // Start D.O.R.A/S.A.R.R exchange to acquire station ip address and\r
  // other pxe boot information.\r
  //\r
  Status = PxeBc->Dhcp (PxeBc, TRUE);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  //\r
  // Select a boot server from boot server list.\r
  //\r
  Status = PxeBcSelectBootPrompt (Private);\r
\r
  if (Status == EFI_SUCCESS) {\r
    //\r
    // Choose by user's input.\r
    //\r
    Status = PxeBcSelectBootMenu (Private, &Type, FALSE);\r
  } else if (Status == EFI_TIMEOUT) {\r
    //\r
    // Choose by default item.\r
    //\r
    Status = PxeBcSelectBootMenu (Private, &Type, TRUE);\r
  }\r
\r
  if (!EFI_ERROR (Status)) {\r
    if (Type == EFI_PXE_BASE_CODE_BOOT_TYPE_BOOTSTRAP) {\r
      //\r
      // Local boot(PXE bootstrap server) need abort\r
      //\r
      return EFI_ABORTED;\r
    }\r
\r
    //\r
    // Start to discover the boot server to get (m)tftp server ip address, bootfile\r
    // name and bootfile size.\r
    //\r
    UseBis = (BOOLEAN)(Mode->BisSupported && Mode->BisDetected);\r
    Status = PxeBc->Discover (PxeBc, Type, &Layer, UseBis, NULL);\r
    if (EFI_ERROR (Status)) {\r
      return Status;\r
    }\r
\r
    if (Mode->PxeReplyReceived && !Mode->ProxyOfferReceived) {\r
      //\r
      // Some network boot loader only search the packet in Mode.ProxyOffer to get its server\r
      // IP address, so we need to store a copy of Mode.PxeReply packet into Mode.ProxyOffer.\r
      //\r
      if (Mode->UsingIpv6) {\r
        CopyMem (\r
          &Mode->ProxyOffer.Dhcpv6,\r
          &Mode->PxeReply.Dhcpv6,\r
          Private->PxeReply.Dhcp6.Packet.Ack.Length\r
          );\r
      } else {\r
        CopyMem (\r
          &Mode->ProxyOffer.Dhcpv4,\r
          &Mode->PxeReply.Dhcpv4,\r
          Private->PxeReply.Dhcp4.Packet.Ack.Length\r
          );\r
      }\r
\r
      Mode->ProxyOfferReceived = TRUE;\r
    }\r
  }\r
\r
  //\r
  // Parse the boot information.\r
  //\r
  if (Mode->UsingIpv6) {\r
    Status = PxeBcDhcp6BootInfo (Private, BufferSize);\r
  } else {\r
    Status = PxeBcDhcp4BootInfo (Private, BufferSize);\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Install PxeBaseCodeCallbackProtocol if not installed before.\r
\r
  @param[in, out] Private           Pointer to PxeBc private data.\r
  @param[out]     NewMakeCallback   If TRUE, it is a new callback.\r
                                    Otherwise, it is not new callback.\r
  @retval EFI_SUCCESS          PxeBaseCodeCallbackProtocol installed successfully.\r
  @retval Others               Failed to install PxeBaseCodeCallbackProtocol.\r
\r
**/\r
EFI_STATUS\r
PxeBcInstallCallback (\r
  IN OUT PXEBC_PRIVATE_DATA  *Private,\r
  OUT BOOLEAN                *NewMakeCallback\r
  )\r
{\r
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;\r
  EFI_STATUS                  Status;\r
\r
  //\r
  // Check whether PxeBaseCodeCallbackProtocol already installed.\r
  //\r
  PxeBc  = &Private->PxeBc;\r
  Status = gBS->HandleProtocol (\r
                  Private->Mode.UsingIpv6 ? Private->Ip6Nic->Controller : Private->Ip4Nic->Controller,\r
                  &gEfiPxeBaseCodeCallbackProtocolGuid,\r
                  (VOID **)&Private->PxeBcCallback\r
                  );\r
  if (Status == EFI_UNSUPPORTED) {\r
    CopyMem (\r
      &Private->LoadFileCallback,\r
      &gPxeBcCallBackTemplate,\r
      sizeof (EFI_PXE_BASE_CODE_CALLBACK_PROTOCOL)\r
      );\r
\r
    //\r
    // Install a default callback if user didn't offer one.\r
    //\r
    Status = gBS->InstallProtocolInterface (\r
                    Private->Mode.UsingIpv6 ? &Private->Ip6Nic->Controller : &Private->Ip4Nic->Controller,\r
                    &gEfiPxeBaseCodeCallbackProtocolGuid,\r
                    EFI_NATIVE_INTERFACE,\r
                    &Private->LoadFileCallback\r
                    );\r
\r
    (*NewMakeCallback) = (BOOLEAN)(Status == EFI_SUCCESS);\r
\r
    Status = PxeBc->SetParameters (PxeBc, NULL, NULL, NULL, NULL, NewMakeCallback);\r
    if (EFI_ERROR (Status)) {\r
      PxeBc->Stop (PxeBc);\r
      return Status;\r
    }\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Uninstall PxeBaseCodeCallbackProtocol.\r
\r
  @param[in]  Private           Pointer to PxeBc private data.\r
  @param[in]  NewMakeCallback   If TRUE, it is a new callback.\r
                                Otherwise, it is not new callback.\r
\r
**/\r
VOID\r
PxeBcUninstallCallback (\r
  IN PXEBC_PRIVATE_DATA  *Private,\r
  IN BOOLEAN             NewMakeCallback\r
  )\r
{\r
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;\r
\r
  PxeBc = &Private->PxeBc;\r
\r
  if (NewMakeCallback) {\r
    NewMakeCallback = FALSE;\r
\r
    PxeBc->SetParameters (PxeBc, NULL, NULL, NULL, NULL, &NewMakeCallback);\r
\r
    gBS->UninstallProtocolInterface (\r
           Private->Mode.UsingIpv6 ? Private->Ip6Nic->Controller : Private->Ip4Nic->Controller,\r
           &gEfiPxeBaseCodeCallbackProtocolGuid,\r
           &Private->LoadFileCallback\r
           );\r
  }\r
}\r
\r
/**\r
  Download one of boot file in the list, and it's special for IPv6.\r
\r
  @param[in]      Private           Pointer to PxeBc private data.\r
  @param[in, out] BufferSize        Size of user buffer for input;\r
                                    required buffer size for output.\r
  @param[in]      Buffer            Pointer to user buffer.\r
\r
  @retval EFI_SUCCESS               Read one of boot file in the list successfully.\r
  @retval EFI_BUFFER_TOO_SMALL      The buffer size is not enough for boot file.\r
  @retval EFI_NOT_FOUND             There is no proper boot file available.\r
  @retval Others                    Failed to download boot file in the list.\r
\r
**/\r
EFI_STATUS\r
PxeBcReadBootFileList (\r
  IN     PXEBC_PRIVATE_DATA  *Private,\r
  IN OUT UINT64              *BufferSize,\r
  IN     VOID                *Buffer           OPTIONAL\r
  )\r
{\r
  EFI_STATUS                  Status;\r
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;\r
\r
  PxeBc = &Private->PxeBc;\r
\r
  //\r
  // Try to download the boot file if everything is ready.\r
  //\r
  if (Buffer != NULL) {\r
    Status = PxeBc->Mtftp (\r
                      PxeBc,\r
                      EFI_PXE_BASE_CODE_TFTP_READ_FILE,\r
                      Buffer,\r
                      FALSE,\r
                      BufferSize,\r
                      &Private->BlockSize,\r
                      &Private->ServerIp,\r
                      Private->BootFileName,\r
                      NULL,\r
                      FALSE\r
                      );\r
  } else {\r
    Status = EFI_BUFFER_TOO_SMALL;\r
  }\r
\r
  return Status;\r
}\r
\r
/**\r
  Load boot file into user buffer.\r
\r
  @param[in]      Private           Pointer to PxeBc private data.\r
  @param[in, out] BufferSize        Size of user buffer for input;\r
                                    required buffer size for output.\r
  @param[in]      Buffer            Pointer to user buffer.\r
\r
  @retval EFI_SUCCESS          Get all the boot information successfully.\r
  @retval EFI_BUFFER_TOO_SMALL The buffer size is not enough for boot file.\r
  @retval EFI_ABORTED          User cancelled the current operation.\r
  @retval Others               Failed to parse out the boot information.\r
\r
**/\r
EFI_STATUS\r
PxeBcLoadBootFile (\r
  IN     PXEBC_PRIVATE_DATA  *Private,\r
  IN OUT UINTN               *BufferSize,\r
  IN     VOID                *Buffer         OPTIONAL\r
  )\r
{\r
  BOOLEAN                     NewMakeCallback;\r
  UINT64                      RequiredSize;\r
  UINT64                      CurrentSize;\r
  EFI_STATUS                  Status;\r
  EFI_PXE_BASE_CODE_PROTOCOL  *PxeBc;\r
  EFI_PXE_BASE_CODE_MODE      *PxeBcMode;\r
\r
  NewMakeCallback = FALSE;\r
  PxeBc           = &Private->PxeBc;\r
  PxeBcMode       = &Private->Mode;\r
  CurrentSize     = *BufferSize;\r
  RequiredSize    = 0;\r
\r
  //\r
  // Install pxebc callback protocol if hasn't been installed yet.\r
  //\r
  Status = PxeBcInstallCallback (Private, &NewMakeCallback);\r
  if (EFI_ERROR (Status)) {\r
    return Status;\r
  }\r
\r
  if (Private->BootFileSize == 0) {\r
    //\r
    // Discover the boot information about the bootfile if hasn't.\r
    //\r
    Status = PxeBcDiscoverBootFile (Private, &RequiredSize);\r
    if (EFI_ERROR (Status)) {\r
      goto ON_EXIT;\r
    }\r
\r
    if (PXEBC_IS_SIZE_OVERFLOWED (RequiredSize)) {\r
      //\r
      // It's error if the required buffer size is beyond the system scope.\r
      //\r
      Status = EFI_DEVICE_ERROR;\r
      goto ON_EXIT;\r
    } else if (RequiredSize > 0) {\r
      //\r
      // Get the right buffer size of the bootfile required.\r
      //\r
      if ((CurrentSize < RequiredSize) || (Buffer == NULL)) {\r
        //\r
        // It's buffer too small if the size of user buffer is smaller than the required.\r
        //\r
        CurrentSize = RequiredSize;\r
        Status      = EFI_BUFFER_TOO_SMALL;\r
        goto ON_EXIT;\r
      }\r
\r
      CurrentSize = RequiredSize;\r
    } else if ((RequiredSize == 0) && PxeBcMode->UsingIpv6) {\r
      //\r
      // Try to download another bootfile in list if failed to get the filesize of the last one.\r
      // It's special for the case of IPv6.\r
      //\r
      Status = PxeBcReadBootFileList (Private, &CurrentSize, Buffer);\r
      goto ON_EXIT;\r
    }\r
  } else if ((CurrentSize < Private->BootFileSize) || (Buffer == NULL)) {\r
    //\r
    // It's buffer too small if the size of user buffer is smaller than the required.\r
    //\r
    CurrentSize = Private->BootFileSize;\r
    Status      = EFI_BUFFER_TOO_SMALL;\r
    goto ON_EXIT;\r
  }\r
\r
  //\r
  // Begin to download the bootfile if everything is ready.\r
  //\r
  AsciiPrint ("\n Downloading NBP file...\n");\r
  if (PxeBcMode->UsingIpv6) {\r
    Status = PxeBcReadBootFileList (\r
               Private,\r
               &CurrentSize,\r
               Buffer\r
               );\r
  } else {\r
    Status = PxeBc->Mtftp (\r
                      PxeBc,\r
                      EFI_PXE_BASE_CODE_TFTP_READ_FILE,\r
                      Buffer,\r
                      FALSE,\r
                      &CurrentSize,\r
                      &Private->BlockSize,\r
                      &Private->ServerIp,\r
                      Private->BootFileName,\r
                      NULL,\r
                      FALSE\r
                      );\r
  }\r
\r
ON_EXIT:\r
  *BufferSize = (UINTN)CurrentSize;\r
  PxeBcUninstallCallback (Private, NewMakeCallback);\r
\r
  if (Status == EFI_SUCCESS) {\r
    AsciiPrint ("\n  NBP file downloaded successfully.\n");\r
    return EFI_SUCCESS;\r
  } else if ((Status == EFI_BUFFER_TOO_SMALL) && (Buffer != NULL)) {\r
    AsciiPrint ("\n  PXE-E05: Buffer size is smaller than the requested file.\n");\r
  } else if (Status == EFI_DEVICE_ERROR) {\r
    AsciiPrint ("\n  PXE-E07: Network device error.\n");\r
  } else if (Status == EFI_OUT_OF_RESOURCES) {\r
    AsciiPrint ("\n  PXE-E09: Could not allocate I/O buffers.\n");\r
  } else if (Status == EFI_NO_MEDIA) {\r
    AsciiPrint ("\n  PXE-E12: Could not detect network connection.\n");\r
  } else if (Status == EFI_NO_RESPONSE) {\r
    AsciiPrint ("\n  PXE-E16: No valid offer received.\n");\r
  } else if (Status == EFI_TIMEOUT) {\r
    AsciiPrint ("\n  PXE-E18: Server response timeout.\n");\r
  } else if (Status == EFI_ABORTED) {\r
    AsciiPrint ("\n  PXE-E21: Remote boot cancelled.\n");\r
  } else if (Status == EFI_ICMP_ERROR) {\r
    AsciiPrint ("\n  PXE-E22: Client received ICMP error from server.\n");\r
  } else if (Status == EFI_TFTP_ERROR) {\r
    AsciiPrint ("\n  PXE-E23: Client received TFTP error from server.\n");\r
  } else if (Status == EFI_NOT_FOUND) {\r
    AsciiPrint ("\n  PXE-E53: No boot filename received.\n");\r
  } else if (Status != EFI_BUFFER_TOO_SMALL) {\r
    AsciiPrint ("\n  PXE-E99: Unexpected network error.\n");\r
  }\r
\r
  return Status;\r
}\r