From b3ba0d934670df86adaac8b110c9f75fd901921b Mon Sep 17 00:00:00 2001
From: Michael Turner <miketur@microsoft.com>
Date: Thu, 8 Dec 2022 14:48:03 -0800
Subject: [PATCH] Add debug messages for DHCP state changes, Tftp progress, and
 PxeBc progress. (#188)

## Description

Add DEBUG message to Dhcp4Dxe

- [ No] Breaking change?
- Will this change break pre-existing builds or functionality without
action being taken?

## How This Was Tested

Not tested

## Integration Instructions

To only get the DHCP debug messages, edit your platform build .dsc to
add the debug flag to

Current:
NetworkPkg/Dhcp4Dxe/Dhcp4Dxe.inf

To get the new DEBUG_NET messages from Dhcp4Dxe:
  NetworkPkg/Dhcp4Dxe/Dhcp4Dxe.inf {
    <PcdsPatchableInModule>
      gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel|0x80084246
    <PcdsFixedAtBuild>
      gEfiMdePkgTokenSpaceGuid.PcdFixedDebugPrintErrorLevel|0x80084246
}

Co-authored-by: kuqin12 <42554914+kuqin12@users.noreply.github.com>
---
 NetworkPkg/Dhcp4Dxe/Dhcp4Impl.c     |  7 ++++++
 NetworkPkg/Dhcp4Dxe/Dhcp4Io.c       | 38 ++++++++++++++++++++++++++++-
 NetworkPkg/Mtftp4Dxe/Mtftp4Impl.c   | 12 +++++++++
 NetworkPkg/Mtftp4Dxe/Mtftp4Rrq.c    | 16 ++++++++++++
 NetworkPkg/Mtftp4Dxe/Mtftp4Wrq.c    |  6 +++++
 NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c |  3 +++
 NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c |  6 +++++
 7 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/NetworkPkg/Dhcp4Dxe/Dhcp4Impl.c b/NetworkPkg/Dhcp4Dxe/Dhcp4Impl.c
index 24a0693942..351487b446 100644
--- a/NetworkPkg/Dhcp4Dxe/Dhcp4Impl.c
+++ b/NetworkPkg/Dhcp4Dxe/Dhcp4Impl.c
@@ -788,11 +788,13 @@ EfiDhcp4Start (
   DhcpSb = Instance->Service;
 
   if (DhcpSb->DhcpState == Dhcp4Stopped) {
+    DEBUG ((DEBUG_NET | DEBUG_ERROR, "%a: failed, in stopped state.\n", __FUNCTION__));
     Status = EFI_NOT_STARTED;
     goto ON_ERROR;
   }
 
   if ((DhcpSb->DhcpState != Dhcp4Init) && (DhcpSb->DhcpState != Dhcp4InitReboot)) {
+    DEBUG ((DEBUG_NET | DEBUG_ERROR, "%a: failed, !Init and !InitReboot state.\n", __FUNCTION__));
     Status = EFI_ALREADY_STARTED;
     goto ON_ERROR;
   }
@@ -903,11 +905,13 @@ EfiDhcp4RenewRebind (
   DhcpSb = Instance->Service;
 
   if (DhcpSb->DhcpState == Dhcp4Stopped) {
+    DEBUG ((DEBUG_NET, "%a: failed, Dhcp4Stopped.\n", __FUNCTION__));
     Status = EFI_NOT_STARTED;
     goto ON_EXIT;
   }
 
   if (DhcpSb->DhcpState != Dhcp4Bound) {
+    DEBUG ((DEBUG_NET, "%a: failed, !Dhcp4Bound.\n", __FUNCTION__));
     Status = EFI_ACCESS_DENIED;
     goto ON_EXIT;
   }
@@ -1016,6 +1020,7 @@ EfiDhcp4Release (
   DhcpSb = Instance->Service;
 
   if ((DhcpSb->DhcpState != Dhcp4InitReboot) && (DhcpSb->DhcpState != Dhcp4Bound)) {
+    DEBUG ((DEBUG_NET, "%a: failed, !InitReboot and !Bound.\n", __FUNCTION__));
     Status = EFI_ACCESS_DENIED;
     goto ON_EXIT;
   }
@@ -1085,6 +1090,8 @@ EfiDhcp4Stop (
 
   DhcpCleanLease (DhcpSb);
 
+  DEBUG ((DEBUG_NET, "%a: new state is Dhcp4Stopped.\n", __FUNCTION__));
+
   DhcpSb->DhcpState    = Dhcp4Stopped;
   DhcpSb->ServiceState = DHCP_UNCONFIGED;
 
diff --git a/NetworkPkg/Dhcp4Dxe/Dhcp4Io.c b/NetworkPkg/Dhcp4Dxe/Dhcp4Io.c
index 238e186c5b..e53b7c66e3 100644
--- a/NetworkPkg/Dhcp4Dxe/Dhcp4Io.c
+++ b/NetworkPkg/Dhcp4Dxe/Dhcp4Io.c
@@ -39,6 +39,7 @@ DhcpInitRequest (
     Status = DhcpSendMessage (DhcpSb, NULL, NULL, DHCP_MSG_DISCOVER, NULL);
 
     if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_NET | DEBUG_ERROR, "%a: SendError, new state is Dhcp4Init. Code=%r\n", __FUNCTION__, Status));
       DhcpSb->DhcpState = Dhcp4Init;
       return Status;
     }
@@ -47,6 +48,7 @@ DhcpInitRequest (
     Status = DhcpSendMessage (DhcpSb, NULL, NULL, DHCP_MSG_REQUEST, NULL);
 
     if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_NET | DEBUG_ERROR, "%a: SendError, new state is Dhcp4InitReboot. Code-%r\n", __FUNCTION__, Status));
       DhcpSb->DhcpState = Dhcp4InitReboot;
       return Status;
     }
@@ -86,6 +88,8 @@ DhcpCallUser (
     *NewPacket = NULL;
   }
 
+  DEBUG ((DEBUG_NET, "%a: Calling user code with DhcpState=%d.\n", __FUNCTION__, Event));
+
   //
   // If user doesn't provide the call back function, return the value
   // that directs the client to continue the normal process.
@@ -184,6 +188,8 @@ DhcpSetState (
 {
   EFI_STATUS  Status;
 
+  DEBUG ((DEBUG_NET, "%a: Setting state to %d, CallUser=%d.\n", __FUNCTION__, State, CallUser));
+
   if (CallUser) {
     Status = EFI_SUCCESS;
 
@@ -425,6 +431,8 @@ DhcpCleanLease (
   IN DHCP_SERVICE  *DhcpSb
   )
 {
+  DEBUG ((DEBUG_NET, "%a: Setting state to Init.\n", __FUNCTION__));
+
   DhcpSb->DhcpState  = Dhcp4Init;
   DhcpSb->Xid        = DhcpSb->Xid + 1;
   DhcpSb->ClientAddr = 0;
@@ -568,8 +576,10 @@ DhcpEndSession (
   )
 {
   if (DHCP_CONNECTED (DhcpSb->DhcpState)) {
+    DEBUG ((DEBUG_NET, "%a: AddressLost.\n", __FUNCTION__));
     DhcpCallUser (DhcpSb, Dhcp4AddressLost, NULL, NULL);
   } else {
+    DEBUG ((DEBUG_NET, "%a: Fail.\n", __FUNCTION__));
     DhcpCallUser (DhcpSb, Dhcp4Fail, NULL, NULL);
   }
 
@@ -869,22 +879,28 @@ DhcpHandleReboot (
     DhcpCallUser (DhcpSb, Dhcp4RcvdNak, Packet, NULL);
 
     DhcpSb->ClientAddr = 0;
-    DhcpSb->DhcpState  = Dhcp4Init;
+    DEBUG ((DEBUG_NET, "%a: NAK received, going to Init\n", __FUNCTION__));
+
+    DhcpSb->DhcpState = Dhcp4Init;
 
     Status = DhcpInitRequest (DhcpSb);
     goto ON_EXIT;
   }
 
+  DEBUG ((DEBUG_NET, "%a: ACK Received.\n", __FUNCTION__));
+
   //
   // Check whether the ACK matches the selected offer
   //
   if (EFI_NTOHL (Head->YourAddr) != DhcpSb->ClientAddr) {
+    DEBUG ((DEBUG_NET, "%a: ACK didn't match offer.\n", __FUNCTION__));
     Status = EFI_DEVICE_ERROR;
     goto ON_EXIT;
   }
 
   Status = DhcpCallUser (DhcpSb, Dhcp4RcvdAck, Packet, NULL);
   if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_NET, "%a: Error from CallUser - %r.\n", __FUNCTION__, Status));
     goto ON_EXIT;
   }
 
@@ -893,6 +909,7 @@ DhcpHandleReboot (
   //
   DhcpSb->Para = AllocateCopyPool (sizeof (DHCP_PARAMETER), Para);
   if (DhcpSb->Para == NULL) {
+    DEBUG ((DEBUG_NET, "%a: Out of resources.\n", __FUNCTION__));
     Status = EFI_OUT_OF_RESOURCES;
     goto ON_EXIT;
   }
@@ -900,11 +917,13 @@ DhcpHandleReboot (
   DhcpSb->Selected = Packet;
   Status           = DhcpLeaseAcquired (DhcpSb);
   if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_NET, "%a: Error from LeaseAcquired - %r.\n", __FUNCTION__, Status));
     return Status;
   }
 
   DhcpSb->IoStatus = EFI_SUCCESS;
   DhcpNotifyUser (DhcpSb, DHCP_NOTIFY_COMPLETION);
+  DEBUG ((DEBUG_NET, "%a: DHCP Complete.\n", __FUNCTION__));
   return EFI_SUCCESS;
 
 ON_EXIT:
@@ -954,6 +973,7 @@ DhcpInput (
   ASSERT (UdpPacket != NULL);
 
   if (DhcpSb->DhcpState == Dhcp4Stopped) {
+    DEBUG ((DEBUG_NET, "%a: Restarting due to state == Stopped.\n", __FUNCTION__));
     goto RESTART;
   }
 
@@ -961,6 +981,7 @@ DhcpInput (
   // Validate the packet received
   //
   if (UdpPacket->TotalSize < sizeof (EFI_DHCP4_HEADER)) {
+    DEBUG ((DEBUG_NET, "%a: Restarting due to invalid header size.\n", __FUNCTION__));
     goto RESTART;
   }
 
@@ -971,6 +992,7 @@ DhcpInput (
   Packet = (EFI_DHCP4_PACKET *)AllocatePool (Len);
 
   if (Packet == NULL) {
+    DEBUG ((DEBUG_NET, "%a: Restarting due to out of resources.\n", __FUNCTION__));
     goto RESTART;
   }
 
@@ -979,6 +1001,7 @@ DhcpInput (
   Packet->Length = NetbufCopy (UdpPacket, 0, UdpPacket->TotalSize, (UINT8 *)Head);
 
   if (Packet->Length != UdpPacket->TotalSize) {
+    DEBUG ((DEBUG_NET, "%a: Restarting due to incorrect packet length.\n", __FUNCTION__));
     goto RESTART;
   }
 
@@ -989,6 +1012,7 @@ DhcpInput (
       (NTOHL (Head->Xid) != DhcpSb->Xid) ||
       (CompareMem (DhcpSb->ClientAddressSendOut, Head->ClientHwAddr, Head->HwAddrLen) != 0))
   {
+    DEBUG ((DEBUG_NET, "%a: Restarting due to not our answer.\n", __FUNCTION__));
     goto RESTART;
   }
 
@@ -1000,6 +1024,7 @@ DhcpInput (
       (Packet->Dhcp4.Magik == DHCP_OPTION_MAGIC) &&
       EFI_ERROR (DhcpValidateOptions (Packet, &Para)))
   {
+    DEBUG ((DEBUG_NET, "%a: Restarting due to bad options.\n", __FUNCTION__));
     goto RESTART;
   }
 
@@ -1017,10 +1042,12 @@ DhcpInput (
   switch (DhcpSb->DhcpState) {
     case Dhcp4Selecting:
       Status = DhcpHandleSelect (DhcpSb, Packet, Para);
+      DEBUG ((DEBUG_NET, "%a: Selecting - code=%r.\n", __FUNCTION__, Status));
       break;
 
     case Dhcp4Requesting:
       Status = DhcpHandleRequest (DhcpSb, Packet, Para);
+      DEBUG ((DEBUG_NET, "%a: Requesting - code=%r.\n", __FUNCTION__, Status));
       break;
 
     case Dhcp4InitReboot:
@@ -1029,6 +1056,7 @@ DhcpInput (
       //
       // Ignore the packet in INITREBOOT, INIT and BOUND states
       //
+      DEBUG ((DEBUG_NET, "%a: Ignoring Init, InitReboot, Bound.\n", __FUNCTION__));
       FreePool (Packet);
       Status = EFI_SUCCESS;
       break;
@@ -1036,10 +1064,12 @@ DhcpInput (
     case Dhcp4Renewing:
     case Dhcp4Rebinding:
       Status = DhcpHandleRenewRebind (DhcpSb, Packet, Para);
+      DEBUG ((DEBUG_NET, "%a: Renew/Rebinding - code=%r.\n", __FUNCTION__, Status));
       break;
 
     case Dhcp4Rebooting:
       Status = DhcpHandleReboot (DhcpSb, Packet, Para);
+      DEBUG ((DEBUG_NET, "%a: Rebooting - code=%r.\n", __FUNCTION__, Status));
       break;
   }
 
@@ -1391,6 +1421,8 @@ DhcpRetransmit (
 
   ASSERT (DhcpSb->LastPacket != NULL);
 
+  DEBUG ((DEBUG_NET, "%a: Entry...\n", __FUNCTION__));
+
   //
   // For REQUEST message in Dhcp4Requesting state, do not change the secs fields.
   //
@@ -1523,6 +1555,7 @@ DhcpOnTimerTick (
         }
 
         DhcpSb->IoStatus = EFI_TIMEOUT;
+        DEBUG ((DEBUG_NET, "%a: Timeout\n", __FUNCTION__));
         DhcpNotifyUser (DhcpSb, DHCP_NOTIFY_RENEWREBIND);
       }
     } else {
@@ -1607,6 +1640,7 @@ DhcpOnTimerTick (
     Instance = NET_LIST_USER_STRUCT (Entry, DHCP_PROTOCOL, Link);
     Instance->Timeout--;
     if ((Instance->Timeout == 0) && (Instance->Token != NULL)) {
+      DEBUG ((DEBUG_NET, "%a: Calling PxeDhcpDone\n", __FUNCTION__));
       PxeDhcpDone (Instance);
     }
   }
@@ -1614,6 +1648,8 @@ DhcpOnTimerTick (
   return;
 
 END_SESSION:
+  DEBUG ((DEBUG_NET, "%a: Ending session with timeout\n", __FUNCTION__));
+
   DhcpEndSession (DhcpSb, EFI_TIMEOUT);
 
   return;
diff --git a/NetworkPkg/Mtftp4Dxe/Mtftp4Impl.c b/NetworkPkg/Mtftp4Dxe/Mtftp4Impl.c
index 211ddbcdcc..b9fd80fa20 100644
--- a/NetworkPkg/Mtftp4Dxe/Mtftp4Impl.c
+++ b/NetworkPkg/Mtftp4Dxe/Mtftp4Impl.c
@@ -492,6 +492,8 @@ Mtftp4Start (
   //
   Token->Status = EFI_NOT_READY;
 
+  DEBUG ((DEBUG_NET, "%a: Starting request, type=%d\n", __FUNCTION__, (UINT32)Operation));
+
   //
   // Build and send an initial requests
   //
@@ -637,6 +639,8 @@ EfiMtftp4Configure (
     return EFI_INVALID_PARAMETER;
   }
 
+  DEBUG ((DEBUG_NET, "%a: Entry\n", __FUNCTION__));
+
   Instance = MTFTP4_PROTOCOL_FROM_THIS (This);
 
   if (ConfigData == NULL) {
@@ -693,6 +697,8 @@ EfiMtftp4Configure (
     gBS->RestoreTPL (OldTpl);
   }
 
+  DEBUG ((DEBUG_NET, "%a: Exit Success\n", __FUNCTION__));
+
   return EFI_SUCCESS;
 }
 
@@ -794,6 +800,8 @@ EfiMtftp4ReadFile (
   IN EFI_MTFTP4_TOKEN     *Token
   )
 {
+  DEBUG ((DEBUG_NET, "%a: Entry\n", __FUNCTION__));
+
   return Mtftp4Start (This, Token, EFI_MTFTP4_OPCODE_RRQ);
 }
 
@@ -854,6 +862,8 @@ EfiMtftp4WriteFile (
   IN EFI_MTFTP4_TOKEN     *Token
   )
 {
+  DEBUG ((DEBUG_NET, "%a: Entry\n", __FUNCTION__));
+
   return Mtftp4Start (This, Token, EFI_MTFTP4_OPCODE_WRQ);
 }
 
@@ -923,6 +933,8 @@ EfiMtftp4ReadDirectory (
   IN EFI_MTFTP4_TOKEN     *Token
   )
 {
+  DEBUG ((DEBUG_NET, "%a: Entry\n", __FUNCTION__));
+
   return Mtftp4Start (This, Token, EFI_MTFTP4_OPCODE_DIR);
 }
 
diff --git a/NetworkPkg/Mtftp4Dxe/Mtftp4Rrq.c b/NetworkPkg/Mtftp4Dxe/Mtftp4Rrq.c
index 75aaa80617..4962797632 100644
--- a/NetworkPkg/Mtftp4Dxe/Mtftp4Rrq.c
+++ b/NetworkPkg/Mtftp4Dxe/Mtftp4Rrq.c
@@ -49,6 +49,8 @@ Mtftp4RrqStart (
 {
   EFI_STATUS  Status;
 
+  DEBUG ((DEBUG_NET, "%a: Entry\n", __FUNCTION__));
+
   //
   // The valid block number range are [1, 0xffff]. For example:
   // the client sends an RRQ request to the server, the server
@@ -273,6 +275,7 @@ Mtftp4RrqHandleData (
   Status = Mtftp4RrqSaveBlock (Instance, Packet, Len);
 
   if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_NET, "%a: Error = %r\n", __FUNCTION__, Status));
     return Status;
   }
 
@@ -429,6 +432,7 @@ Mtftp4RrqConfigMcastPort (
   Status = McastIo->Protocol.Udp4->Configure (McastIo->Protocol.Udp4, &UdpConfig);
 
   if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_NET, "%a: Error = %r\n", __FUNCTION__, Status));
     return Status;
   }
 
@@ -448,6 +452,7 @@ Mtftp4RrqConfigMcastPort (
                                        );
 
     if (EFI_ERROR (Status)) {
+      DEBUG ((DEBUG_NET, "%a: Error2 = %r\n", __FUNCTION__, Status));
       McastIo->Protocol.Udp4->Configure (McastIo->Protocol.Udp4, NULL);
       return Status;
     }
@@ -527,6 +532,8 @@ Mtftp4RrqHandleOack (
         );
     }
 
+    DEBUG ((DEBUG_NET, "%a: TFTP ERROR(%d) = %r\n", __FUNCTION__, __LINE__, Status));
+
     return EFI_TFTP_ERROR;
   }
 
@@ -546,6 +553,8 @@ Mtftp4RrqHandleOack (
           (UINT8 *)"Illegal multicast setting"
           );
 
+        DEBUG ((DEBUG_NET, "%a: TFTP ERROR(%d) = %r\n", __FUNCTION__, __LINE__, Status));
+
         return EFI_TFTP_ERROR;
       }
 
@@ -592,6 +601,8 @@ Mtftp4RrqHandleOack (
           (UINT8 *)"Failed to create socket to receive multicast packet"
           );
 
+        DEBUG ((DEBUG_NET, "%a: TFTP ERROR(%d) = %r\n", __FUNCTION__, __LINE__, Status));
+
         return Status;
       }
 
@@ -669,6 +680,7 @@ Mtftp4RrqInput (
 
   if (EFI_ERROR (IoStatus)) {
     Status = IoStatus;
+    DEBUG ((DEBUG_NET, "%a: TFTP ERROR(%d) = %r\n", __FUNCTION__, __LINE__, Status));
     goto ON_EXIT;
   }
 
@@ -744,6 +756,8 @@ Mtftp4RrqInput (
           );
       }
 
+      DEBUG ((DEBUG_NET, "%a: TFTP ERROR(%d) = %r\n", __FUNCTION__, __LINE__, Status));
+
       Status = EFI_ABORTED;
       goto ON_EXIT;
     }
@@ -798,6 +812,8 @@ Mtftp4RrqInput (
     }
   }
 
+  DEBUG ((DEBUG_NET, "%a: Completed=%d. Code=%r\n", __FUNCTION__, Completed, Status));
+
   if (EFI_ERROR (Status) || Completed) {
     Mtftp4CleanOperation (Instance, Status);
   }
diff --git a/NetworkPkg/Mtftp4Dxe/Mtftp4Wrq.c b/NetworkPkg/Mtftp4Dxe/Mtftp4Wrq.c
index 9ebefc74ec..0fe0658de6 100644
--- a/NetworkPkg/Mtftp4Dxe/Mtftp4Wrq.c
+++ b/NetworkPkg/Mtftp4Dxe/Mtftp4Wrq.c
@@ -465,6 +465,8 @@ Mtftp4WrqInput (
     Status = UdpIoRecvDatagram (Instance->UnicastPort, Mtftp4WrqInput, Instance, 0);
   }
 
+  DEBUG ((DEBUG_NET, "%a: Completed=%d. Code=%r\n", __FUNCTION__, Completed, Status));
+
   //
   // Status may have been updated by UdpIoRecvDatagram
   //
@@ -495,6 +497,8 @@ Mtftp4WrqStart (
 {
   EFI_STATUS  Status;
 
+  DEBUG ((DEBUG_NET, "%a: Entry\n", __FUNCTION__));
+
   //
   // The valid block number range are [0, 0xffff]. For example:
   // the client sends an WRQ request to the server, the server
@@ -504,12 +508,14 @@ Mtftp4WrqStart (
   Status = Mtftp4InitBlockRange (&Instance->Blocks, 0, 0xffff);
 
   if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_NET, "%a: TFTP ERROR(%d) = %r\n", __FUNCTION__, __LINE__, Status));
     return Status;
   }
 
   Status = Mtftp4SendRequest (Instance);
 
   if (EFI_ERROR (Status)) {
+    DEBUG ((DEBUG_NET, "%a: TFTP ERROR(%d) = %r\n", __FUNCTION__, __LINE__, Status));
     return Status;
   }
 
diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c b/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c
index 54aeb1d30e..1d92f48be3 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcBoot.c
@@ -1219,6 +1219,7 @@ PxeBcLoadBootFile (
   // Begin to download the bootfile if everything is ready.
   //
   AsciiPrint ("\n Downloading NBP file...\n");
+  DEBUG ((DEBUG_NET, "%a:  Downloading NBP file...\n", __FUNCTION__));
   if (PxeBcMode->UsingIpv6) {
     Status = PxeBcReadBootFileList (
                Private,
@@ -1244,6 +1245,8 @@ PxeBcLoadBootFile (
   *BufferSize = (UINTN)CurrentSize;
   PxeBcUninstallCallback (Private, NewMakeCallback);
 
+  DEBUG ((DEBUG_NET, "%a:  Complete, code = %r\n", __FUNCTION__, Status));
+
   if (Status == EFI_SUCCESS) {
     AsciiPrint ("\n  NBP file downloaded successfully.\n");
     return EFI_SUCCESS;
diff --git a/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c b/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c
index eb21c38727..e4e823e31a 100644
--- a/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c
+++ b/NetworkPkg/UefiPxeBcDxe/PxeBcImpl.c
@@ -2375,6 +2375,8 @@ EfiPxeLoadFile (
   EFI_STATUS                  Status;
   EFI_STATUS                  MediaStatus;
 
+  DEBUG ((DEBUG_NET, "%a: Entry\n", __FUNCTION__));
+
   if ((This == NULL) || (BufferSize == NULL) || (FilePath == NULL) || !IsDevicePathEnd (FilePath)) {
     return EFI_INVALID_PARAMETER;
   }
@@ -2383,6 +2385,7 @@ EfiPxeLoadFile (
   // Only support BootPolicy
   //
   if (!BootPolicy) {
+    DEBUG ((DEBUG_NET, "%a: !BootPolicy\n", __FUNCTION__));
     return EFI_UNSUPPORTED;
   }
 
@@ -2398,6 +2401,7 @@ EfiPxeLoadFile (
   MediaStatus = EFI_SUCCESS;
   NetLibDetectMediaWaitTimeout (Private->Controller, PXEBC_CHECK_MEDIA_WAITING_TIME, &MediaStatus);
   if (MediaStatus != EFI_SUCCESS) {
+    DEBUG ((DEBUG_NET, "%a: No Media\n", __FUNCTION__));
     return EFI_NO_MEDIA;
   }
 
@@ -2449,6 +2453,8 @@ EfiPxeLoadFile (
     }
   }
 
+  DEBUG ((DEBUG_NET, "%a: Completed, Code = %r\n", __FUNCTION__, Status));
+
   return Status;
 }