From: niry <niry@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Mon, 29 Dec 2008 01:16:13 +0000 (+0000)
Subject: 1). Fix the debug level for DEBUG macro
X-Git-Tag: edk2-stable201903~19104
X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=f381602727922e793de5826ee390344cb907e07a

1). Fix the debug level for DEBUG macro
2). Uniform the function description comments

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7143 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Callback.c b/MdeModulePkg/Universal/Network/SnpDxe/Callback.c
index c4789ba11d..fc018265c7 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Callback.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Callback.c
@@ -30,20 +30,22 @@ EFI_LOCK             mLock;
 //
 extern EFI_PCI_IO_PROTOCOL  *mPciIo;
 
-/**
-  This is a callback routine supplied to UNDI at undi_start time.
-  UNDI call this routine with a virtual or CPU address that SNP provided to 
-  convert it to a physical or device address. Since EFI uses the identical 
-  mapping, this routine returns the physical address same as the virtual address
-  for most of the addresses. an address above 4GB cannot generally be used as a 
-  device address, it needs to be mapped to a lower physical address. This 
-  routine does not call the map routine itself, but it assumes that the mapping
-  was done at the time of providing the address to UNDI. This routine just 
-  looks up the address in a map table (which is the v2p structure chain). 
+/** 
+  Convert a virtual or CPU address provided by SNP to a physical or device 
+  address. 
+
+  This is a callback routine supplied to UNDI at undi_start time. Since EFI uses
+  the identical mapping, this routine returns the physical address same as the 
+  virtual address for most of the addresses. an address above 4GB cannot 
+  generally be used as a device address, it needs to be mapped to a lower 
+  physical address. This routine does not call the map routine itself, but it 
+  assumes that the mapping was done at the time of providing the address to 
+  UNDI. This routine just looks up the address in a map table (which is the v2p 
+  structure chain). 
   
-  @param  CpuAddr        virtual address of a buffer.
-  @param  DeviceAddrPtr  pointer to the physical address.
-                         The DeviceAddrPtr will contain 0 in case of any error.
+  @param  CpuAddr        Virtual address.
+  @param  DeviceAddrPtr  Pointer to the physical address, or 0 in case of any 
+                         error.
 
 **/
 VOID
@@ -59,7 +61,7 @@ SnpUndi32CallbackV2p30 (
   // EFI uses identical mapping
   //
   if ((CpuAddr == 0) || (DeviceAddrPtr == 0)) {
-    DEBUG ((EFI_D_NET, "\nv2p: Null virtual address or physical pointer.\n"));
+    DEBUG ((EFI_D_INFO | EFI_D_NET, "\nv2p: Null virtual address or physical pointer.\n"));
     return ;
   }
 
@@ -80,12 +82,12 @@ SnpUndi32CallbackV2p30 (
 }
 
 /**
+  Acquire or release a lock of an exclusive access to a critical section of the
+  code/data. 
+
   This is a callback routine supplied to UNDI at undi_start time.
-  UNDI call this routine when it wants to have exclusive access to a critical
-  section of the code/data.
 
-  @param Enable   non-zero indicates acquire
-                  zero indicates release
+  @param Enable   Non-zero indicates acquire; Zero indicates release.
 
 **/
 VOID
@@ -110,11 +112,11 @@ SnpUndi32CallbackBlock30 (
 }
 
 /**
+  Delay MicroSeconds of micro seconds.
+   
   This is a callback routine supplied to UNDI at undi_start time.
-  UNDI call this routine with the number of micro seconds when it wants to
-  pause.
 
-  @param MicroSeconds  number of micro seconds to pause, ususlly multiple of 10.
+  @param MicroSeconds  Number of micro seconds to pause, ususlly multiple of 10.
 
 **/
 VOID
@@ -128,21 +130,22 @@ SnpUndi32CallbackDelay30 (
 }
 
 /**
-  This is a callback routine supplied to UNDI at undi_start time.
-  This is the IO routine for UNDI. This is not currently being used by UNDI3.0
-  because Undi3.0 uses io/mem offsets relative to the beginning of the device
-  io/mem address and so it needs to use the PCI_IO_FUNCTION that abstracts the
-  start of the device's io/mem addresses. Since SNP cannot retrive the context
-  of the undi3.0 interface it cannot use the PCI_IO_FUNCTION that specific for
-  that NIC and uses one global IO functions structure, this does not work.
-  This however works fine for EFI1.0 Undis because they use absolute addresses
-  for io/mem access.
-
-  @param ReadOrWrite  indicates read or write, IO or Memory
-  @param NumBytes     number of bytes to read or write
-  @param Address      IO or memory address to read from or write to
-  @param BufferAddr   memory location to read into or that contains the bytes to 
-                      write
+  IO routine for UNDI. 
+
+  This is a callback routine supplied to UNDI at undi_start time. This is not 
+  currently being used by UNDI3.0 because Undi3.0 uses io/mem offsets relative 
+  to the beginning of the device io/mem address and so it needs to use the 
+  PCI_IO_FUNCTION that abstracts the start of the device's io/mem addresses. 
+  Since SNP cannot retrive the context of the undi3.0 interface it cannot use 
+  the PCI_IO_FUNCTION that specific for that NIC and uses one global IO 
+  functions structure, this does not work. This however works fine for EFI1.0 
+  Undis because they use absolute addresses for io/mem access. 
+
+  @param ReadOrWrite  Indicates read or write, IO or Memory.
+  @param NumBytes     Number of bytes to read or write.
+  @param Address      IO or memory address to read from or write to.
+  @param BufferAddr   Memory location to read into or that contains the bytes to
+                      write.
 
 **/
 VOID
@@ -222,18 +225,18 @@ SnpUndi32CallbackMemio30 (
 }
 
 /**
+  Acquire or release a lock of the exclusive access to a critical section of the 
+  code/data. 
+   
   This is a callback routine supplied to UNDI3.1 at undi_start time.
-  UNDI call this routine when it wants to have exclusive access to a critical
-  section of the code/data.
-  New callbacks for 3.1:
-  there won't be a virtual2physical callback for UNDI 3.1 because undi3.1 uses
-  the MemMap call to map the required address by itself!
+  New callbacks for 3.1: there won't be a virtual2physical callback for UNDI 3.1
+  because undi3.1 uses the MemMap call to map the required address by itself! 
 
   @param UniqueId  This was supplied to UNDI at Undi_Start, SNP uses this to 
-   								 store Undi interface context (Undi does not read or write
-   								 this variable)
-  @param Enable    non-zero indicates acquire
-                   zero indicates release
+                      store Undi interface context (Undi does not read or write
+                      this variable).
+  @param Enable    Non-zero indicates acquire; Zero indicates release. 
+
 **/
 VOID
 SnpUndi32CallbackBlock (
@@ -256,14 +259,15 @@ SnpUndi32CallbackBlock (
 }
 
 /**
+  Delay MicroSeconds of micro seconds.
+   
   This is a callback routine supplied to UNDI at undi_start time.
-  UNDI call this routine with the number of micro seconds when it wants to
-  pause.
 
   @param UniqueId      This was supplied to UNDI at Undi_Start, SNP uses this to
-   								     store Undi interface context (Undi does not read or write
-   								     this variable)
-  @param MicroSeconds  number of micro seconds to pause, ususlly multiple of 10.
+                       store Undi interface context (Undi does not read or write
+                       this variable).
+  @param MicroSeconds  Number of micro seconds to pause, ususlly multiple of 10.  
+
 **/
 VOID
 SnpUndi32CallbackDelay (
@@ -277,17 +281,19 @@ SnpUndi32CallbackDelay (
 }
 
 /**
+  IO routine for UNDI3.1. 
+   
   This is a callback routine supplied to UNDI at undi_start time.
-  This is the IO routine for UNDI3.1 to start CPB.
-
+   
   @param UniqueId       This was supplied to UNDI at Undi_Start, SNP uses this 
-   											to store Undi interface context (Undi does not read or
-   											write this variable)
-  @param ReadOrWrite    indicates read or write, IO or Memory.
-  @param NumBytes       number of bytes to read or write.
+                       	to store Undi interface context (Undi does not read or
+                       	write this variable).
+  @param ReadOrWrite    Indicates read or write, IO or Memory.
+  @param NumBytes       Number of bytes to read or write.
   @param MemOrPortAddr  IO or memory address to read from or write to.
-  @param BufferPtr      memory location to read into or that contains the bytes
-                        to write.
+  @param BufferPtr      Memory location to read into or that contains the bytes
+                       	to write.
+
 **/
 VOID
 SnpUndi32CallbackMemio (
@@ -368,17 +374,18 @@ SnpUndi32CallbackMemio (
 }
 
 /**
+  Map a CPU address to a device address. 
+
   This is a callback routine supplied to UNDI at undi_start time.
-  UNDI call this routine when it has to map a CPU address to a device
-  address.
 
-  @param UniqueId      - This was supplied to UNDI at Undi_Start, SNP uses this to store
-                         Undi interface context (Undi does not read or write this variable)
-  @param CpuAddr       - Virtual address to be mapped!
-  @param NumBytes      - size of memory to be mapped
-  @param Direction     - direction of data flow for this memory's usage:
-                         cpu->device, device->cpu or both ways
-  @param DeviceAddrPtr - pointer to return the mapped device address
+  @param UniqueId      This was supplied to UNDI at Undi_Start, SNP uses this to
+                       store Undi interface context (Undi does not read or write
+                       this variable).
+  @param CpuAddr       Virtual address to be mapped.
+  @param NumBytes      Size of memory to be mapped.
+  @param Direction     Direction of data flow for this memory's usage:
+                       cpu->device, device->cpu or both ways.
+  @param DeviceAddrPtr Pointer to return the mapped device address.
 
 **/
 VOID
@@ -460,17 +467,18 @@ SnpUndi32CallbackMap (
 }
 
 /**
+  Unmap an address that was previously mapped using map callback. 
+   
   This is a callback routine supplied to UNDI at undi_start time.
-  UNDI call this routine when it wants to unmap an address that was previously
-  mapped using map callback.
 
-  @param UniqueId    This was supplied to UNDI at Undi_Start, SNP uses this to store.
-                     Undi interface context (Undi does not read or write this variable)
-  @param CpuAddr     Virtual address that was mapped!
-  @param NumBytes    size of memory mapped
-  @param Direction   direction of data flow for this memory's usage:
-                     cpu->device, device->cpu or both ways
-  @param DeviceAddr  the mapped device address
+  @param UniqueId    This was supplied to UNDI at Undi_Start, SNP uses this to 
+                     store. Undi interface context (Undi does not read or write
+                     this variable).
+  @param CpuAddr     Virtual address that was mapped.
+  @param NumBytes    Size of memory mapped.
+  @param Direction   Direction of data flow for this memory's usage: 
+                     cpu->device, device->cpu or both ways.
+  @param DeviceAddr  The mapped device address.
 
 **/
 VOID
@@ -493,8 +501,7 @@ SnpUndi32CallbackUnmap (
     }
   }
 
-  if (Index >= MAX_MAP_LENGTH)
-  {
+  if (Index >= MAX_MAP_LENGTH) {
     DEBUG ((EFI_D_ERROR, "SNP could not find a mapping, failed to unmap.\n"));
     return ;
   }
@@ -505,25 +512,26 @@ SnpUndi32CallbackUnmap (
   return ;
 }
 
-/**
-  This is a callback routine supplied to UNDI at undi_start time.
-  UNDI call this routine when it wants synchronize the virtual buffer contents
-  with the mapped buffer contents. The virtual and mapped buffers need not
-  correspond to the same physical memory (especially if the virtual address is
-  > 4GB). Depending on the direction for which the buffer is mapped, undi will
-  need to synchronize their contents whenever it writes to/reads from the buffer
-  using either the cpu address or the device address.
-
-  EFI does not provide a sync call, since virt=physical, we sould just do
-  the synchronization ourself here!
-
-  @param UniqueId    This was supplied to UNDI at Undi_Start, SNP uses this to store
-                     Undi interface context (Undi does not read or write this variable)
-  @param CpuAddr     Virtual address that was mapped!
-  @param NumBytes    size of memory mapped.
-  @param Direction   direction of data flow for this memory's usage:
+/** 
+  Synchronize the virtual buffer contents with the mapped buffer contents. 
+   
+  This is a callback routine supplied to UNDI at undi_start time. The virtual
+  and mapped buffers need not correspond to the same physical memory (especially 
+  if the virtual address is > 4GB). Depending on the direction for which the 
+  buffer is mapped, undi will need to synchronize their contents whenever it 
+  writes to/reads from the buffer using either the cpu address or the device 
+  address. 
+  EFI does not provide a sync call since virt=physical, we should just do the 
+  synchronization ourselves here. 
+
+  @param UniqueId    This was supplied to UNDI at Undi_Start, SNP uses this to 
+                     store Undi interface context (Undi does not read or write
+                     this variable).
+  @param CpuAddr     Virtual address that was mapped.
+  @param NumBytes    Size of memory mapped.
+  @param Direction   Direction of data flow for this memory's usage:
                      cpu->device, device->cpu or both ways.
-  @param DeviceAddr  the mapped device address.
+  @param DeviceAddr  The mapped device address.
 
 **/
 VOID
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/ComponentName.c b/MdeModulePkg/Universal/Network/SnpDxe/ComponentName.c
index 304e6205fd..956cd59c8b 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/ComponentName.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/ComponentName.c
@@ -242,7 +242,8 @@ SimpleNetworkComponentNameGetDriverName (
   and EFI_SUCCESS is returned.  If the driver specified by This is not currently
   managing the controller specified by ControllerHandle and ChildHandle,
   then EFI_UNSUPPORTED is returned.  If the driver specified by This does not
-  support the language specified by Language, then EFI_UNSUPPORTED is returned.
+  support the language specified by Language, then EFI_UNSUPPORTED is returned. 
+  Currently not implemented. 
 
   @param  This[in]              A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
                                 EFI_COMPONENT_NAME_PROTOCOL instance.
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Get_status.c b/MdeModulePkg/Universal/Network/SnpDxe/Get_status.c
index 17078c81cf..e2c911dfd2 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Get_status.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Get_status.c
@@ -16,15 +16,19 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include "Snp.h"
 
 /**
-  this routine calls undi to get the status of the interrupts, get the list of
-  transmit buffers that completed transmitting!
-
-  @param  Snp                     pointer to snp driver structure
-  @param  InterruptStatusPtr      a non null pointer gets the interrupt status
-  @param  TransmitBufferListPtrs  a non null ointer gets the list of pointers of
-                                  previously  transmitted buffers whose
-                                  transmission was completed  asynchrnously.
-
+  Call undi to get the status of the interrupts, get the list of transmit 
+  buffers that completed transmitting. 
+
+  @param  Snp                     Pointer to snp driver structure.
+  @param  InterruptStatusPtr      A non null pointer to contain the interrupt 
+                                  status.
+  @param  TransmitBufferListPtrs  A non null pointer to contain the list of 
+                                  pointers of previous transmitted buffers whose
+                                  transmission was completed asynchrnously.
+   
+  @retval EFI_SUCCESS         The status of the network interface was retrieved.
+  @retval EFI_DEVICE_ERROR    The command could not be sent to the network 
+                              interface.
 
 **/
 EFI_STATUS
@@ -68,13 +72,13 @@ PxeGetStatus (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nSnp->undi.get_status()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->undi.get_status()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
   if (Snp->Cdb.StatCode != EFI_SUCCESS) {
     DEBUG (
-      (EFI_D_NET,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nSnp->undi.get_status()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatFlags)
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c b/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c
index 5337b1cc2e..43b517e9e6 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Initialize.c
@@ -16,14 +16,15 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include "Snp.h"
 
 /**
-  this routine calls undi to initialize the interface.
+  Call UNDI to initialize the interface.
 
-  @param  Snp                   pointer to snp driver structure
-  @param  CableDetectFlag       Do/don't detect the cable (depending on what undi supports)
+  @param  Snp                   Pointer to snp driver structure.
+  @param  CableDetectFlag       Do/don't detect the cable (depending on what 
+                                undi supports).
   
-  @retval EFI_SUCCESS           UNDI is initialized successfully
-  @retval EFI_DEVICE_ERROR      UNDI could not be initialized
-  @retval Other                 other errors 
+  @retval EFI_SUCCESS           UNDI is initialized successfully.
+  @retval EFI_DEVICE_ERROR      UNDI could not be initialized.
+  @retval Other                 Other errors as indicated.
 
 **/
 EFI_STATUS
@@ -94,7 +95,7 @@ PxeInit (
   Snp->Cdb.IFnum      = Snp->IfNum;
   Snp->Cdb.Control    = PXE_CONTROL_LAST_CDB_IN_LIST;
 
-  DEBUG ((EFI_D_NET, "\nSnp->undi.initialize()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->undi.initialize()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -104,7 +105,7 @@ PxeInit (
     Status          = EFI_SUCCESS;
   } else {
     DEBUG (
-      (EFI_D_WARN,
+      (EFI_D_ERROR,
       "\nSnp->undi.initialize()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Mcast_ip_to_mac.c b/MdeModulePkg/Universal/Network/SnpDxe/Mcast_ip_to_mac.c
index 00c80eb95f..e11b54afaa 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Mcast_ip_to_mac.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Mcast_ip_to_mac.c
@@ -16,13 +16,18 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include "Snp.h"
 
 /**
-  this routine calls undi to convert an multicast IP address to a MAC address.
+  Call undi to convert an multicast IP address to a MAC address.
 
-  @param  Snp   pointer to snp driver structure
-  @param  IPv6  flag to indicate if this is an ipv6 address
-  @param  IP    multicast IP address
-  @param  MAC   pointer to hold the return MAC address
+  @param  Snp   Pointer to snp driver structure.
+  @param  IPv6  Flag to indicate if this is an ipv6 address.
+  @param  IP    Multicast IP address.
+  @param  MAC   Pointer to hold the return MAC address.
 
+  @retval EFI_SUCCESS           The multicast IP address was mapped to the 
+                                multicast HW MAC address.
+  @retval EFI_INVALID_PARAMETER Invalid UNDI command. 
+  @retval EFI_UNSUPPORTED       Command is not supported by UNDI. 
+  @retval EFI_DEVICE_ERROR      Fail to execute UNDI command. 
 
 **/
 EFI_STATUS
@@ -56,7 +61,7 @@ PxeIp2Mac (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nSnp->undi.mcast_ip_to_mac()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->undi.mcast_ip_to_mac()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -69,7 +74,7 @@ PxeIp2Mac (
 
   case PXE_STATCODE_UNSUPPORTED:
     DEBUG (
-      (EFI_D_NET,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nSnp->undi.mcast_ip_to_mac()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
@@ -82,7 +87,7 @@ PxeIp2Mac (
     // to caller.
     //
     DEBUG (
-      (EFI_D_NET,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nSnp->undi.mcast_ip_to_mac()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Nvdata.c b/MdeModulePkg/Universal/Network/SnpDxe/Nvdata.c
index 4b9259f87a..d7c55a6f10 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Nvdata.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Nvdata.c
@@ -24,6 +24,10 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
   @param  BufferSize   number of bytes to read
   @param  Buffer       pointer where to read into
 
+  @retval EFI_SUCCESS           The NVRAM access was performed.
+  @retval EFI_INVALID_PARAMETER Invalid UNDI command.
+  @retval EFI_UNSUPPORTED       Command is not supported by UNDI.
+  @retval EFI_DEVICE_ERROR      Fail to execute UNDI command.
 
 **/
 EFI_STATUS
@@ -55,7 +59,7 @@ PxeNvDataRead (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.nvdata ()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.nvdata ()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -65,7 +69,7 @@ PxeNvDataRead (
 
   case PXE_STATCODE_UNSUPPORTED:
     DEBUG (
-      (EFI_D_NET,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nsnp->undi.nvdata()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
@@ -75,7 +79,7 @@ PxeNvDataRead (
 
   default:
     DEBUG (
-      (EFI_D_NET,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nsnp->undi.nvdata()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Receive.c b/MdeModulePkg/Universal/Network/SnpDxe/Receive.c
index bfabe11aa5..2392498283 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Receive.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Receive.c
@@ -16,21 +16,29 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #include "Snp.h"
 
 /**
-  this routine calls undi to receive a packet and fills in the data in the
-  input pointers!
-
-  @param  Snp                 pointer to snp driver structure
-  @param  Buffer           pointer to the memory for the received data
-  @param  BufferSize         is a pointer to the length of the buffer on entry and
-                              contains the length of the received data on return
-  @param  HeaderSize       pointer to the header portion of the data received.
-  @param  SrcAddr       optional parameter, is a pointer to contain the
-                              source ethernet address on return
-  @param  DestAddr  optional parameter, is a pointer to contain the
-                              destination ethernet address on return
-  @param  Protocol         optional parameter, is a pointer to contain the
-                              protocol type from the ethernet header on return
+  Call UNDI to receive a packet and fills in the data in the input pointers.
 
+  @param  Snp          Pointer to snp driver structure
+  @param  Buffer       Pointer to the memory for the received data
+  @param  BufferSize   Pointer to the length of the buffer on entry and contains
+                       the length of the received data on return
+  @param  HeaderSize   Pointer to the header portion of the data received.
+  @param  SrcAddr      Pointer to contain the source ethernet address on return 
+  @param  DestAddr     Pointer to contain the destination ethernet address on 
+                       return
+  @param  Protocol     Pointer to contain the protocol type from the ethernet 
+                       header on return
+
+
+  @retval EFI_SUCCESS           The received data was stored in Buffer, and 
+                                BufferSize has been updated to the number of 
+                                bytes received.
+  @retval EFI_DEVICE_ERROR      Fail to execute UNDI command. 
+  @retval EFI_NOT_READY         No packets have been received on the network 
+                                interface.
+  @retval EFI_BUFFER_TOO_SMALL  BufferSize is too small for the received 
+                                packets. BufferSize has been updated to the
+                                required size.
 
 **/
 EFI_STATUS
@@ -74,7 +82,7 @@ PxeReceive (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.receive ()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.receive ()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -84,7 +92,7 @@ PxeReceive (
 
   case PXE_STATCODE_NO_DATA:
     DEBUG (
-      (EFI_D_NET,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nsnp->undi.receive ()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
@@ -94,7 +102,7 @@ PxeReceive (
 
   default:
     DEBUG (
-      (EFI_D_ERROR,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nsnp->undi.receive()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
@@ -118,7 +126,10 @@ PxeReceive (
   }
 
   if (Protocol != NULL) {
-    *Protocol = (UINT16) PXE_SWAP_UINT16 (Db->Protocol); /*  we need to do the byte swapping */
+    //
+    // We need to do the byte swapping
+    //
+    *Protocol = (UINT16) PXE_SWAP_UINT16 (Db->Protocol);
   }
 
   return (*BufferSize <= BuffSize) ? EFI_SUCCESS : EFI_BUFFER_TOO_SMALL;
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Receive_filters.c b/MdeModulePkg/Universal/Network/SnpDxe/Receive_filters.c
index db116330cd..24e89c5b48 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Receive_filters.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Receive_filters.c
@@ -1,21 +1,16 @@
 /** @file
-Copyright (c) 2004 - 2007, Intel Corporation
-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
+    Implementation of managing the multicast receive filters of a network
+    interface.
+
+Copyright (c) 2004 - 2007, 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.
 
-Module name:
-  receive_filters.c
-
-Abstract:
-
-Revision history:
-  2000-Feb-17 M(f)J   Genesis.
-
 **/
 
 
@@ -23,14 +18,18 @@ Revision history:
 #include "Snp.h"
 
 /**
-  this routine calls undi to enable the receive filters.
-
-  @param  Snp                pointer to snp driver structure
-  @param  EnableFlags        bit mask for enabling the receive filters
-  @param  MCastAddressCount  multicast address count for a new multicast address
-                             list
-  @param  MCastAddressList   list of new multicast addresses
+  Call undi to enable the receive filters.
 
+  @param  Snp                Pointer to snp driver structure.
+  @param  EnableFlags        Bit mask for enabling the receive filters.
+  @param  MCastAddressCount  Multicast address count for a new multicast address
+                             list.
+  @param  MCastAddressList   List of new multicast addresses. 
+   
+  @retval EFI_SUCCESS           The multicast receive filter list was updated.
+  @retval EFI_INVALID_PARAMETER Invalid UNDI command.
+  @retval EFI_UNSUPPORTED       Command is not supported by UNDI.
+  @retval EFI_DEVICE_ERROR      Fail to execute UNDI command.
 
 **/
 EFI_STATUS
@@ -80,7 +79,7 @@ PxeRecvFilterEnable (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.receive_filters()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.receive_filters()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -112,14 +111,17 @@ PxeRecvFilterEnable (
 }
 
 /**
-  this routine calls undi to disable the receive filters.
+  Call undi to disable the receive filters.
 
-  @param  Snp                pointer to snp driver structure
-  @param  DisableFlags       bit mask for disabling the receive filters
-  @param  ResetMCastList     boolean flag to reset/delete the multicast filter list
+  @param  Snp             Pointer to snp driver structure
+  @param  DisableFlags    Bit mask for disabling the receive filters
+  @param  ResetMCastList  Boolean flag to reset/delete the multicast filter 
+                          list.
 
-
-**/
+  @retval EFI_SUCCESS           The multicast receive filter list was updated.
+  @retval EFI_DEVICE_ERROR      Fail to execute UNDI command.
+   
+**/ 
 EFI_STATUS
 PxeRecvFilterDisable (
   SNP_DRIVER *Snp,
@@ -165,7 +167,7 @@ PxeRecvFilterDisable (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.receive_filters()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.receive_filters()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -174,7 +176,7 @@ PxeRecvFilterDisable (
     // UNDI command failed.  Return UNDI status to caller.
     //
     DEBUG (
-      (EFI_D_ERROR,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nsnp->undi.receive_filters()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
@@ -187,11 +189,13 @@ PxeRecvFilterDisable (
 }
 
 /**
-  this routine calls undi to read the receive filters.
-
-  @param  Snp                pointer to snp driver structure
+  Call undi to read the receive filters.
 
+  @param  Snp                Pointer to snp driver structure.
 
+  @retval EFI_SUCCESS           The receive filter was read.
+  @retval EFI_DEVICE_ERROR      Fail to execute UNDI command. 
+   
 **/
 EFI_STATUS
 PxeRecvFilterRead (
@@ -215,7 +219,7 @@ PxeRecvFilterRead (
   Snp->Cdb.IFnum      = Snp->IfNum;
   Snp->Cdb.Control    = PXE_CONTROL_LAST_CDB_IN_LIST;
 
-  DEBUG ((EFI_D_NET, "\nsnp->undi.receive_filters()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.receive_filters()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Reset.c b/MdeModulePkg/Universal/Network/SnpDxe/Reset.c
index f616d43584..057d3b51c5 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Reset.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Reset.c
@@ -1,33 +1,27 @@
 /** @file
-Copyright (c) 2004 - 2007, Intel Corporation
-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
+    Implementation of resetting a network adapter.
+ 
+Copyright (c) 2004 - 2007, 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.
 
-Module name:
-  reset.c
-
-Abstract:
-
-Revision history:
-  2000-Feb-09 M(f)J   Genesis.
-
 **/
 
 #include "Snp.h"
 
 
 /**
-  This routine calls undi to reset the nic.
+  Call UNDI to reset the NIC.
 
-  @param  Snp                   pointer to the snp driver structure
+  @param  Snp                 Pointer to the snp driver structure.
 
-  @return EFI_SUCCESSFUL for a successful completion
-  @return other for failed calls
+  @return EFI_SUCCESSFUL      The NIC was reset.
+  @retval EFI_DEVICE_ERROR    The NIC cannot be reset.
 
 **/
 EFI_STATUS
@@ -49,13 +43,13 @@ PxeReset (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.reset()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.reset()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
   if (Snp->Cdb.StatCode != PXE_STATCODE_SUCCESS) {
     DEBUG (
-      (EFI_D_WARN,
+      (EFI_D_ERROR | EFI_D_NET,
       "\nsnp->undi32.reset()  %xh:%xh\n",
       Snp->Cdb.StatFlags,
       Snp->Cdb.StatCode)
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Shutdown.c b/MdeModulePkg/Universal/Network/SnpDxe/Shutdown.c
index a996c2c50a..21ed2bfe20 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Shutdown.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Shutdown.c
@@ -16,12 +16,12 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 
 /**
-  this routine calls undi to shut down the interface.
+  Call UNDI to shut down the interface.
 
-  @param  Snp   pointer to snp driver structure
+  @param  Snp   Pointer to snp driver structure.
 
-  @retval EFI_SUCCESS        UNDI is shut down successfully
-  @retval EFI_DEVICE_ERROR   UNDI could not be shut down
+  @retval EFI_SUCCESS        UNDI is shut down successfully.
+  @retval EFI_DEVICE_ERROR   UNDI could not be shut down.
 
 **/
 EFI_STATUS
@@ -43,7 +43,7 @@ PxeShutdown (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.shutdown()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.shutdown()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -51,7 +51,7 @@ PxeShutdown (
     //
     // UNDI could not be shutdown. Return UNDI error.
     //
-    DEBUG ((EFI_D_WARN, "\nsnp->undi.shutdown()  %xh:%xh\n", Snp->Cdb.StatFlags, Snp->Cdb.StatCode));
+    DEBUG ((EFI_D_ERROR, "\nsnp->undi.shutdown()  %xh:%xh\n", Snp->Cdb.StatFlags, Snp->Cdb.StatCode));
 
     return EFI_DEVICE_ERROR;
   }
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Snp.c b/MdeModulePkg/Universal/Network/SnpDxe/Snp.c
index 80a05f102f..58451608e5 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Snp.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Snp.c
@@ -24,10 +24,14 @@ V2P                         *mV2p = NULL; // undi3.0 map_list head
 
 
 /**
-  Unsupport currently.
+  Send command to UNDI. It does nothing currently.
   
   @param Cdb   command to be sent to UNDI.
-
+   
+  @retval EFI_INVALID_PARAMETER  The command is 0. 
+  @retval EFI_UNSUPPORTED        Default return status because it's not 
+                                 supported currently.
+   
 **/
 EFI_STATUS
 IssueHwUndiCommand (
@@ -53,8 +57,8 @@ IssueHwUndiCommand (
   @param  Buffer               Pointer to buffer.
   @param  Length               Length of buffer in bytes.
 
-  @return 8-bit checksum of all bytes in buffer.
-  @return If ptr is NULL or len is zero, zero is returned.
+  @return 8-bit checksum of all bytes in buffer, or zero if ptr is NULL or len 
+          is zero.
 
 **/
 UINT8
@@ -89,13 +93,13 @@ Calc8BitCksum (
   Supported() it must also follow these calling restrictions.
 
   @param  This                Protocol instance pointer.
-  @param  ControllerHandle    Handle of device to test
+  @param  ControllerHandle    Handle of device to test.
   @param  RemainingDevicePath Optional parameter use to pick a specific child
                               device to start.
 
-  @retval EFI_SUCCESS         This driver supports this device
-  @retval EFI_ALREADY_STARTED This driver is already running on this device
-  @retval other               This driver does not support this device
+  @retval EFI_SUCCESS         This driver supports this device.
+  @retval EFI_ALREADY_STARTED This driver is already running on this device.
+  @retval other               This driver does not support this device.
 
 **/
 EFI_STATUS
@@ -151,7 +155,7 @@ SimpleNetworkDriverSupported (
   // Check to see if !PXE structure is valid. Paragraph alignment of !PXE structure is required.
   //
   if (NiiProtocol->ID & 0x0F) {
-    DEBUG ((EFI_D_NET, "\n!PXE structure is not paragraph aligned.\n"));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE structure is not paragraph aligned.\n"));
     Status = EFI_UNSUPPORTED;
     goto Done;
   }
@@ -162,25 +166,25 @@ SimpleNetworkDriverSupported (
   //  Verify !PXE revisions.
   //
   if (Pxe->hw.Signature != PXE_ROMID_SIGNATURE) {
-    DEBUG ((EFI_D_NET, "\n!PXE signature is not valid.\n"));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE signature is not valid.\n"));
     Status = EFI_UNSUPPORTED;
     goto Done;
   }
 
   if (Pxe->hw.Rev < PXE_ROMID_REV) {
-    DEBUG ((EFI_D_NET, "\n!PXE.Rev is not supported.\n"));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE.Rev is not supported.\n"));
     Status = EFI_UNSUPPORTED;
     goto Done;
   }
 
   if (Pxe->hw.MajorVer < PXE_ROMID_MAJORVER) {
 
-    DEBUG ((EFI_D_NET, "\n!PXE.MajorVer is not supported.\n"));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE.MajorVer is not supported.\n"));
     Status = EFI_UNSUPPORTED;
     goto Done;
 
   } else if (Pxe->hw.MajorVer == PXE_ROMID_MAJORVER && Pxe->hw.MinorVer < PXE_ROMID_MINORVER) {
-    DEBUG ((EFI_D_NET, "\n!PXE.MinorVer is not supported."));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE.MinorVer is not supported."));
     Status = EFI_UNSUPPORTED;
     goto Done;
   }
@@ -189,13 +193,13 @@ SimpleNetworkDriverSupported (
   //
   if ((Pxe->hw.Implementation & PXE_ROMID_IMP_HW_UNDI) == 0) {
     if (Pxe->sw.EntryPoint < Pxe->sw.Len) {
-      DEBUG ((EFI_D_NET, "\n!PXE S/W entry point is not valid."));
+      DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE S/W entry point is not valid."));
       Status = EFI_UNSUPPORTED;
       goto Done;
     }
 
     if (Pxe->sw.BusCnt == 0) {
-      DEBUG ((EFI_D_NET, "\n!PXE.BusCnt is zero."));
+      DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE.BusCnt is zero."));
       Status = EFI_UNSUPPORTED;
       goto Done;
     }
@@ -254,7 +258,7 @@ SimpleNetworkDriverStart (
   UINT8                                     BarIndex;
   PXE_STATFLAGS                             InitStatFlags;
 
-  DEBUG ((EFI_D_NET, "\nSnpNotifyNetworkInterfaceIdentifier()  "));
+  DEBUG ((EFI_D_INFO, "\nSnpNotifyNetworkInterfaceIdentifier()  "));
 
   Status = gBS->OpenProtocol (
                   Controller,
@@ -316,7 +320,7 @@ SimpleNetworkDriverStart (
   Pxe = (PXE_UNDI *) (UINTN) (Nii->ID);
 
   if (Calc8BitCksum (Pxe, Pxe->hw.Len) != 0) {
-    DEBUG ((EFI_D_NET, "\n!PXE checksum is not correct.\n"));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\n!PXE checksum is not correct.\n"));
     goto NiiError;
   }
 
@@ -331,7 +335,7 @@ SimpleNetworkDriverStart (
     //  broadcast support or we cannot do DHCP!
     //
   } else {
-    DEBUG ((EFI_D_NET, "\nUNDI does not have promiscuous or broadcast support."));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\nUNDI does not have promiscuous or broadcast support."));
     goto NiiError;
   }
   //
@@ -348,7 +352,7 @@ SimpleNetworkDriverStart (
                         );
 
   if (Status != EFI_SUCCESS) {
-    DEBUG ((EFI_D_NET, "\nCould not allocate SNP_DRIVER structure.\n"));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\nCould not allocate SNP_DRIVER structure.\n"));
     goto NiiError;
   }
 
@@ -422,7 +426,7 @@ SimpleNetworkDriverStart (
                         );
 
   if (Status != EFI_SUCCESS) {
-    DEBUG ((EFI_D_NET, "\nCould not allocate CPB and DB structures.\n"));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\nCould not allocate CPB and DB structures.\n"));
     goto Error_DeleteSNP;
   }
 
@@ -464,7 +468,7 @@ SimpleNetworkDriverStart (
   Snp->Cdb.IFnum      = Snp->IfNum;
   Snp->Cdb.Control    = PXE_CONTROL_LAST_CDB_IN_LIST;
 
-  DEBUG ((EFI_D_NET, "\nSnp->undi.get_init_info()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->undi.get_init_info()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -474,7 +478,7 @@ SimpleNetworkDriverStart (
   InitStatFlags = Snp->Cdb.StatFlags;
 
   if (Snp->Cdb.StatCode != PXE_STATCODE_SUCCESS) {
-    DEBUG ((EFI_D_NET, "\nSnp->undi.init_info()  %xh:%xh\n", Snp->Cdb.StatFlags, Snp->Cdb.StatCode));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\nSnp->undi.init_info()  %xh:%xh\n", Snp->Cdb.StatFlags, Snp->Cdb.StatCode));
     PxeStop (Snp);
     goto Error_DeleteSNP;
   }
@@ -494,12 +498,12 @@ SimpleNetworkDriverStart (
   Snp->Cdb.IFnum      = Snp->IfNum;
   Snp->Cdb.Control    = PXE_CONTROL_LAST_CDB_IN_LIST;
 
-  DEBUG ((EFI_D_NET, "\nSnp->undi.get_config_info()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->undi.get_config_info()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
   if (Snp->Cdb.StatCode != PXE_STATCODE_SUCCESS) {
-    DEBUG ((EFI_D_NET, "\nSnp->undi.config_info()  %xh:%xh\n", Snp->Cdb.StatFlags, Snp->Cdb.StatCode));
+    DEBUG ((EFI_D_ERROR | EFI_D_NET, "\nSnp->undi.config_info()  %xh:%xh\n", Snp->Cdb.StatFlags, Snp->Cdb.StatCode));
     PxeStop (Snp);
     goto Error_DeleteSNP;
   }
@@ -609,7 +613,7 @@ SimpleNetworkDriverStart (
   Status = PxeGetStnAddr (Snp);
 
   if (Status != EFI_SUCCESS) {
-    DEBUG ((EFI_D_ERROR, "\nSnp->undi.get_station_addr()  failed.\n"));
+    DEBUG ((EFI_D_ERROR, "\nSnp->undi.get_station_addr() failed.\n"));
     PxeShutdown (Snp);
     PxeStop (Snp);
     goto Error_DeleteSNP;
@@ -811,27 +815,27 @@ AddV2P (
     return EFI_INVALID_PARAMETER;
   }
 
-  *V2p = AllocatePool (sizeof (V2P  ));
+  *V2p = AllocatePool (sizeof (V2P));
   if (*V2p != NULL) {
     return EFI_OUT_OF_RESOURCES;
   }
 
   Status = mPciIo->Map (
-                        mPciIo,
-                        Type,
-                        VirtualAddress,
-                        &BufferSize,
-                        &(*V2p)->PhysicalAddress,
-                        &(*V2p)->Unmap
-                        );
+                     mPciIo,
+                     Type,
+                     VirtualAddress,
+                     &BufferSize,
+                     &(*V2p)->PhysicalAddress,
+                     &(*V2p)->Unmap
+                     );
   if (Status != EFI_SUCCESS) {
     FreePool (*V2p);
     return Status;
   }
   (*V2p)->VirtualAddress = VirtualAddress;
-  (*V2p)->BufferSize = BufferSize;
-  (*V2p)->Next  = mV2p;
-  mV2p          = *V2p;
+  (*V2p)->BufferSize     = BufferSize;
+  (*V2p)->Next           = mV2p;
+  mV2p                   = *V2p;
 
   return EFI_SUCCESS;
 }
@@ -846,8 +850,8 @@ AddV2P (
   @param  VirtualAddr          virtual address (or CPU address) to be searched in
                                the map list
 
-  @retval EFI_SUCEESS          if a match found!
-  @retval Other                match not found
+  @retval EFI_SUCEESS          A match was found.
+  @retval Other                A match cannot be found.
 
 **/
 EFI_STATUS
@@ -874,13 +878,13 @@ FindV2p (
 
 
 /**
-  This routine unmaps the given virtual address and frees the memory allocated
-  for the map list node corresponding to that address.
+  Unmap the given virtual address and free the memory allocated for the map list
+  node corresponding to that address.
 
-  @param  VirtualAddress       virtual address (or CPU address) to be unmapped
+  @param  VirtualAddress       virtual address (or CPU address) to be unmapped.
 
-  @retval EFI_SUCEESS          if successfully unmapped
-  @retval Other                as indicated by the error
+  @retval EFI_SUCEESS          Successfully unmapped.
+  @retval Other                Other errors as indicated.
 
 **/
 EFI_STATUS
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Snp.h b/MdeModulePkg/Universal/Network/SnpDxe/Snp.h
index 675057577c..ff7ad7b444 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Snp.h
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Snp.h
@@ -15,7 +15,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #define _SNP_H_
 
 
-#include <PiDxe.h>
+#include <Uefi.h>
 
 #include <Protocol/SimpleNetwork.h>
 #include <Protocol/PciIo.h>
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/SnpDxe.inf b/MdeModulePkg/Universal/Network/SnpDxe/SnpDxe.inf
index 6d38368549..c143c0b2dc 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/SnpDxe.inf
+++ b/MdeModulePkg/Universal/Network/SnpDxe/SnpDxe.inf
@@ -1,19 +1,16 @@
 #/** @file
-# Component name for module SNP
+#    Component description file for SNP module.
 #
-# FIX ME!
-# Copyright (c) 2006, Intel Corporation.
+# Copyright (c) 2006, 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 
 #
-#  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.
 #
-#  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
-#  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
-#
-#
-#**/
+**/
 
 [Defines]
   INF_VERSION                    = 0x00010005
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Start.c b/MdeModulePkg/Universal/Network/SnpDxe/Start.c
index 5c5daeaa60..5beebad274 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Start.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Start.c
@@ -16,12 +16,12 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 
 /**
-  this routine calls undi to start the interface and changes the snp state.
+  Call UNDI to start the interface and changes the snp state.
 
-  @param  Snp                    pointer to snp driver structure
+  @param  Snp                    pointer to snp driver structure.
 
-  @retval EFI_DEVICE_ERROR       UNDI could not be started
-  @retval EFI_SUCCESS            UNDI is started successfully
+  @retval EFI_SUCCESS            UNDI is started successfully.
+  @retval EFI_DEVICE_ERROR       UNDI could not be started.
   
 **/
 EFI_STATUS
@@ -72,7 +72,7 @@ PxeStart (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.start()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.start()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -99,7 +99,7 @@ PxeStart (
 
 
 /**
-  Changes the state of a network interface from "stopped" to "started."
+  Change the state of a network interface from "stopped" to "started."
   
   This function starts a network interface. If the network interface successfully
   starts, then EFI_SUCCESS will be returned.
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Station_address.c b/MdeModulePkg/Universal/Network/SnpDxe/Station_address.c
index 07df584a07..42792c26e1 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Station_address.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Station_address.c
@@ -16,13 +16,13 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 
 /**
-  this routine calls undi to read the MAC address of the NIC and updates the
-  mode structure with the address.
+  Call UNDI to read the MAC address of the NIC and update the mode structure 
+  with the address. 
 
-  @param  Snp         pointer to snp driver structure.
+  @param  Snp         Pointer to snp driver structure.
    
-  @retval EFI_SUCCESS       the MAC address of the NIC is read successfully.
-  @retval EFI_DEVICE_ERROR  failed to read the MAC address of the NIC.
+  @retval EFI_SUCCESS       The MAC address of the NIC is read successfully.
+  @retval EFI_DEVICE_ERROR  Failed to read the MAC address of the NIC.
 
 **/
 EFI_STATUS
@@ -50,7 +50,7 @@ PxeGetStnAddr (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.station_addr()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.station_addr()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
@@ -90,10 +90,10 @@ PxeGetStnAddr (
 
 
 /**
-  this routine calls undi to set a new MAC address for the NIC,
+  Call UNDI to set a new MAC address for the NIC.
 
-  @param  Snp         pointer to Snp driver structure
-  @param  NewMacAddr  pointer to a mac address to be set for the nic, if this is
+  @param  Snp         Pointer to Snp driver structure.
+  @param  NewMacAddr  Pointer to a MAC address to be set for the NIC, if this is
                       NULL then this routine resets the mac address to the NIC's
                       original address.
 
@@ -139,7 +139,7 @@ PxeSetStnAddr (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.station_addr()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.station_addr()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Statistics.c b/MdeModulePkg/Universal/Network/SnpDxe/Statistics.c
index c52fc23db3..5261a8441c 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Statistics.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Statistics.c
@@ -139,7 +139,7 @@ SnpUndi32Statistics (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.statistics()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.statistics()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Stop.c b/MdeModulePkg/Universal/Network/SnpDxe/Stop.c
index 2eedfcd726..f707ed4fa1 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Stop.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Stop.c
@@ -16,14 +16,12 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 
 /**
-  this routine calls undi to stop the interface and changes the snp state.
+  Call UNDI to stop the interface and changes the snp state.
 
-  @param  Snp   pointer to snp driver structure
-
-  @retval EFI_INVALID_PARAMETER  invalid parameter
-  @retval EFI_NOT_STARTED        SNP is not started
-  @retval EFI_DEVICE_ERROR       SNP is not initialized
-  @retval EFI_UNSUPPORTED        operation unsupported
+  @param  Snp   Pointer to snp driver structure
+   
+  @retval EFI_SUCCESS            The network interface was stopped.
+  @retval EFI_DEVICE_ERROR       SNP is not initialized.
 
 **/
 EFI_STATUS
@@ -45,13 +43,13 @@ PxeStop (
   //
   // Issue UNDI command
   //
-  DEBUG ((EFI_D_NET, "\nsnp->undi.stop()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nsnp->undi.stop()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);
 
   if (Snp->Cdb.StatCode != PXE_STATCODE_SUCCESS) {
     DEBUG (
-      (EFI_D_WARN,
+      (EFI_D_ERROR,
       "\nsnp->undi.stop()  %xh:%xh\n",
       Snp->Cdb.StatCode,
       Snp->Cdb.StatFlags)
@@ -74,15 +72,18 @@ PxeStop (
   interface is in the started state. If the network interface was successfully
   stopped, then EFI_SUCCESS will be returned.
   
-  @param  This                    A pointer to the EFI_SIMPLE_NETWORK_PROTOCOL instance.
+  @param  This                    A pointer to the EFI_SIMPLE_NETWORK_PROTOCOL 
+                                  instance.
   
   
   @retval EFI_SUCCESS             The network interface was stopped.
   @retval EFI_NOT_STARTED         The network interface has not been started.
-  @retval EFI_INVALID_PARAMETER   This parameter was NULL or did not point to a valid 
-                                  EFI_SIMPLE_NETWORK_PROTOCOL structure.
-  @retval EFI_DEVICE_ERROR        The command could not be sent to the network interface.
-  @retval EFI_UNSUPPORTED         This function is not supported by the network interface.
+  @retval EFI_INVALID_PARAMETER   This parameter was NULL or did not point to a 
+                                  valid EFI_SIMPLE_NETWORK_PROTOCOL structure.
+  @retval EFI_DEVICE_ERROR        The command could not be sent to the network 
+                                  interface.
+  @retval EFI_UNSUPPORTED         This function is not supported by the network 
+                                  interface.
 
 **/
 EFI_STATUS
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/Transmit.c b/MdeModulePkg/Universal/Network/SnpDxe/Transmit.c
index c9d8e715aa..f103a59b3f 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/Transmit.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/Transmit.c
@@ -16,19 +16,19 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 
 /**
-  This routine calls undi to create the meadia header for the given data buffer.
+  Call UNDI to create the meadia header for the given data buffer.
 
-  @param  Snp                 pointer to SNP driver structure
-  @param  MacHeaderPtr        address where the media header will be filled in.
-  @param  HeaderSize       size of the memory at MacHeaderPtr
-  @param  Buffer           data buffer pointer
-  @param  BufferSize        Size of data in the Buffer
-  @param  DestAddr  address of the destination mac address buffer
-  @param  SrcAddr       address of the source mac address buffer
-  @param  ProtocolPtr         address of the protocol type
+  @param  Snp              Pointer to SNP driver structure.
+  @param  MacHeaderPtr     Address where the media header will be filled in.
+  @param  HeaderSize       Size of the memory at MacHeaderPtr.
+  @param  Buffer           Data buffer pointer.
+  @param  BufferSize       Size of data in the Buffer
+  @param  DestAddr         Address of the destination mac address buffer.
+  @param  SrcAddr          Address of the source mac address buffer.
+  @param  ProtocolPtr      Address of the protocol type.
 
-  @retval EFI_SUCCESS         if successfully completed the undi call
-  @retval Other               error return from undi call.
+  @retval EFI_SUCCESS      Successfully completed the undi call.
+  @retval Other            Error return from undi call.
 
 **/
 EFI_STATUS
@@ -101,7 +101,7 @@ PxeFillHeader (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nSnp->undi.fill_header()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->undi.fill_header()  "));
 
   (*Snp->IssueUndi32Command) ((UINT64) (UINTN) &Snp->Cdb);
 
@@ -177,16 +177,16 @@ PxeTransmit (
   //
   // Issue UNDI command and check result.
   //
-  DEBUG ((EFI_D_NET, "\nSnp->undi.transmit()  "));
-  DEBUG ((EFI_D_NET, "\nSnp->Cdb.OpCode  == %x", Snp->Cdb.OpCode));
-  DEBUG ((EFI_D_NET, "\nSnp->Cdb.CPBaddr == %LX", Snp->Cdb.CPBaddr));
-  DEBUG ((EFI_D_NET, "\nSnp->Cdb.DBaddr  == %LX", Snp->Cdb.DBaddr));
-  DEBUG ((EFI_D_NET, "\nCpb->FrameAddr   == %LX\n", Cpb->FrameAddr));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->undi.transmit()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->Cdb.OpCode  == %x", Snp->Cdb.OpCode));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->Cdb.CPBaddr == %LX", Snp->Cdb.CPBaddr));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->Cdb.DBaddr  == %LX", Snp->Cdb.DBaddr));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nCpb->FrameAddr   == %LX\n", Cpb->FrameAddr));
 
   (*Snp->IssueUndi32Command) ((UINT64) (UINTN) &Snp->Cdb);
 
-  DEBUG ((EFI_D_NET, "\nexit Snp->undi.transmit()  "));
-  DEBUG ((EFI_D_NET, "\nSnp->Cdb.StatCode == %r", Snp->Cdb.StatCode));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nexit Snp->undi.transmit()  "));
+  DEBUG ((EFI_D_INFO | EFI_D_NET, "\nSnp->Cdb.StatCode == %r", Snp->Cdb.StatCode));
 
   //
   // we will unmap the buffers in get_status call, not here
diff --git a/MdeModulePkg/Universal/Network/SnpDxe/WaitForPacket.c b/MdeModulePkg/Universal/Network/SnpDxe/WaitForPacket.c
index 8dd8fd997e..5acdb7d6d7 100644
--- a/MdeModulePkg/Universal/Network/SnpDxe/WaitForPacket.c
+++ b/MdeModulePkg/Universal/Network/SnpDxe/WaitForPacket.c
@@ -25,8 +25,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 VOID
 EFIAPI
 SnpWaitForPacketNotify (
-  EFI_EVENT Event,
-  VOID      *SnpPtr
+  EFI_EVENT     Event,
+  VOID          *SnpPtr
   )
 {
   PXE_DB_GET_STATUS PxeDbGetStatus;
@@ -90,5 +90,3 @@ SnpWaitForPacketNotify (
     gBS->SignalEvent (Event);
   }
 }
-
-/* eof - WaitForPacket.c */