Various fixes and improvements to UefiExt (#78)

## Description

Contains the following fixes and improvements
1. Created simple `!monitor` command for invoking GDB monitor commands
without the tedious `.exdicmd target:0:...` command. This will also
clean up the output and capture output even if verbose output is
disabled.
2. Add support for a Rust debugger environment
3. in-progress implementation of ELF header dumping
4. Fixed issue with image magic size comparison.
5. Switch `!AdvLog` to use local definition to support parsing without C
symbols.
6. Implemented environment autodetection by capture exdicmd response
output.

- [ ] Impacts functionality?
- [ ] Impacts security?
- [ ] Breaking change?
- [ ] Includes tests?
- [ ] Includes documentation?

## How This Was Tested

Tested locally

## Integration Instructions

N/A

Author: cfernald

UefiDbgExt/memory.cpp

@@ -21,6 +21,20 @@ Module Name:
 //
 
 #pragma pack (push, 1)
+typedef struct {
+  UINT16    Year;
+  UINT8     Month;
+  UINT8     Day;
+  UINT8     Hour;
+  UINT8     Minute;
+  UINT8     Second;
+  UINT8     Pad1;
+  UINT32    Nanosecond;
+  INT16     TimeZone;
+  UINT8     Daylight;
+  UINT8     Pad2;
+} EFI_TIME;
+
 typedef struct {
   UINT32    Signature;          // Signature
   UINT8     MajorVersion;       // Major version of advanced logger message structure
@@ -33,6 +47,29 @@ typedef struct {
                                 // used to calculate the address of the Message
   // CHAR      MessageText[];      // Message Text
 } ADVANCED_LOGGER_MESSAGE_ENTRY_V2;
+
+typedef volatile struct {
+  UINT32      Signature;                          // Signature 'ALOG'
+  UINT16      Version;                            // Current Version
+  UINT16      Reserved[3];                        // Reserved for future
+  UINT32      LogBufferOffset;                    // Offset from LoggerInfo to start of log, expected to be the size of this structure 8 byte aligned
+  UINT32      Reserved4;
+  UINT32      LogCurrentOffset;                   // Offset from LoggerInfo to where to store next log entry.
+  UINT32      DiscardedSize;                      // Number of bytes of messages missed
+  UINT32      LogBufferSize;                      // Size of allocated buffer
+  BOOLEAN     InPermanentRAM;                     // Log in permanent RAM
+  BOOLEAN     AtRuntime;                          // After ExitBootServices
+  BOOLEAN     GoneVirtual;                        // After VirtualAddressChange
+  BOOLEAN     HdwPortInitialized;                 // HdwPort initialized
+  BOOLEAN     HdwPortDisabled;                    // HdwPort is Disabled
+  BOOLEAN     Reserved2[3];                       //
+  UINT64      TimerFrequency;                     // Ticks per second for log timing
+  UINT64      TicksAtTime;                        // Ticks when Time Acquired
+  EFI_TIME    Time;                               // Uefi Time Field
+  UINT32      HwPrintLevel;                       // Logging level to be printed at hw port
+  UINT32      Reserved3;                          //
+} ADVANCED_LOGGER_INFO;
+
 #pragma pack (pop)
 
 PCSTR  MemoryTypeString[] = {
@@ -262,6 +299,7 @@ advlog (
   ULONG                             Offset;
   ULONG                             End;
   ADVANCED_LOGGER_MESSAGE_ENTRY_V2  *Entry;
+  ADVANCED_LOGGER_INFO              Info = { 0 };
 
   // NOTE: This implementation is a crude first past, The following should be done
   // in the future.
@@ -296,8 +334,9 @@ advlog (
     goto Exit;
   }
 
-  GetFieldValue (InfoAddress, "ADVANCED_LOGGER_INFO", "Version", Version);
-  GetFieldValue (InfoAddress, "ADVANCED_LOGGER_INFO", "LogBufferSize", LogBufferSize);
+  ReadMemory (InfoAddress, (PVOID)&Info, sizeof (Info), &BytesRead);
+  Version       = Info.Version;
+  LogBufferSize = Info.LogBufferSize;
 
   g_ExtControl->ControlledOutput (
                   DEBUG_OUTCTL_AMBIENT_DML,
@@ -307,7 +346,7 @@ advlog (
                   InfoAddress
                   );
 
-  dprintf ("Version:  %d\n", Version);
+  dprintf ("Version:  %d\n", Info.Version);
   dprintf ("Size:     0x%x bytes\n", LogBufferSize);
 
   if (LogBufferSize == 0) {
@@ -319,63 +358,70 @@ advlog (
   if (Version == 4) {
     GetFieldValue (InfoAddress, "ADVANCED_LOGGER_INFO", "LogBuffer", EntryAddress);
     GetFieldValue (InfoAddress, "ADVANCED_LOGGER_INFO", "LogCurrent", EndAddress);
-    if (EndAddress < EntryAddress) {
-      dprintf ("Looped logs not yet implemented in extension!\n");
-      Result = ERROR_NOT_SUPPORTED;
-      goto Exit;
-    } else {
-      // non-loop optimization, only download through the last message.
-      LogBufferSize = min (LogBufferSize, (ULONG)(EndAddress - InfoAddress));
-    }
-
-    LogBuffer = (CHAR *)malloc (LogBufferSize);
+  } else if (Version == 5) {
+    EntryAddress = InfoAddress + Info.LogBufferOffset;
+    EndAddress   = InfoAddress + Info.LogCurrentOffset;
+  } else {
+    dprintf ("\nVersion not implemented in debug extension!\n");
+    Result = ERROR_NOT_SUPPORTED;
+    goto Exit;
+  }
 
-    // Output() forces IO flush to inform user.
-    g_ExtControl->Output (DEBUG_OUTPUT_NORMAL, "Reading log (0x%x bytes) ... \n", LogBufferSize);
-    ReadMemory (InfoAddress, LogBuffer, LogBufferSize, &BytesRead);
-    if (BytesRead != LogBufferSize) {
-      dprintf ("Failed to read log memory!\n");
-      Result = ERROR_BAD_LENGTH;
-      goto Exit;
-    }
+  if (EndAddress < EntryAddress) {
+    dprintf ("Looped logs not yet implemented in extension!\n");
+    Result = ERROR_NOT_SUPPORTED;
+    goto Exit;
+  } else {
+    // non-loop optimization, only download through the last message.
+    LogBufferSize = min (LogBufferSize, (ULONG)(EndAddress - InfoAddress));
+  }
 
-    Offset = (ULONG)(EntryAddress - InfoAddress);
-    End    = (ULONG)(EndAddress - InfoAddress);
+  LogBuffer = (CHAR *)malloc (LogBufferSize);
 
-    dprintf ("\n------------------------------------------------------------------------------\n");
-    BOOLEAN  PrevNL = TRUE;
-    while (Offset < End) {
-      Entry = (ADVANCED_LOGGER_MESSAGE_ENTRY_V2 *)(LogBuffer + Offset);
-      if (Entry->Signature != 0x324d4c41) {
-        dprintf ("\nBad message signature!!\n");
-        break;
-      }
+  // Output() forces IO flush to inform user.
+  g_ExtControl->Output (DEBUG_OUTPUT_NORMAL, "Reading log (0x%x bytes) ... \n", LogBufferSize);
+  ReadMemory (InfoAddress, LogBuffer, LogBufferSize, &BytesRead);
+  if (BytesRead != LogBufferSize) {
+    dprintf ("Failed to read log memory!\n");
+    Result = ERROR_BAD_LENGTH;
+    goto Exit;
+  }
 
-      ULONG  StringEnd = Offset + Entry->MessageOffset + Entry->MessageLen;
-      CHAR   Temp      = LogBuffer[StringEnd];
-      LogBuffer[StringEnd] = 0;
+  Offset = (ULONG)(EntryAddress - InfoAddress);
+  End    = (ULONG)(EndAddress - InfoAddress);
 
-      if (PrevNL) {
-        dprintf (
-          "%-8s| %-8s| ",
-          (Entry->Phase < PHASE_COUNT ? PhaseStrings[Entry->Phase] : "UNK"),
-          ErrorLevelToString (Entry->DebugLevel)
-          );
-      }
+  dprintf ("\n------------------------------------------------------------------------------\n");
+  BOOLEAN  PrevNL = TRUE;
 
-      dprintf ("%s", LogBuffer + Offset + Entry->MessageOffset);
-      PrevNL = (LogBuffer[StringEnd - 1] == '\n');
+  while (Offset + sizeof (ADVANCED_LOGGER_MESSAGE_ENTRY_V2) <= End) {
+    Entry = (ADVANCED_LOGGER_MESSAGE_ENTRY_V2 *)(LogBuffer + Offset);
+    if (Entry->Signature != 0x324d4c41) {
+      dprintf ("\nBad message signature!! Entry Offset: 0x%x\n", Offset);
+      break;
+    }
 
-      LogBuffer[StringEnd] = Temp;
+    ULONG  StringEnd = Offset + Entry->MessageOffset + Entry->MessageLen;
+    CHAR   Temp      = LogBuffer[StringEnd];
+    LogBuffer[StringEnd] = 0;
 
-      Offset = ALIGN_UP (Offset + Entry->MessageOffset + Entry->MessageLen, 8);
+    if (PrevNL) {
+      dprintf (
+        "%-8s| %-8s| ",
+        (Entry->Phase < PHASE_COUNT ? PhaseStrings[Entry->Phase] : "UNK"),
+        ErrorLevelToString (Entry->DebugLevel)
+        );
     }
 
-    dprintf ("\n------------------------------------------------------------------------------\n");
-  } else {
-    dprintf ("\nVersion not implemented in debug extension!\n");
+    dprintf ("%s", LogBuffer + Offset + Entry->MessageOffset);
+    PrevNL = (LogBuffer[StringEnd - 1] == '\n');
+
+    LogBuffer[StringEnd] = Temp;
+
+    Offset = ALIGN_UP (Offset + Entry->MessageOffset + Entry->MessageLen, 8);
   }
 
+  dprintf ("\n------------------------------------------------------------------------------\n");
+
   Result = S_OK;
 
 Exit:

UefiDbgExt/modules.cpp

@@ -26,7 +26,8 @@ FindModuleBackwards (
   CHAR           Command[512];
   ULONG64        MaxSize;
   ULONG32        Check;
-  CONST ULONG32  Magic = 0x5A4D;  // MZ
+  CONST ULONG32  Magic    = 0x5A4D;     // MZ
+  CONST ULONG32  ElfMagic = 0x464C457F; // 0x7F_ELF
   ULONG          BytesRead;
   HRESULT        Result;
   ULONG64        Base;
@@ -50,14 +51,28 @@ FindModuleBackwards (
   for ( ; Address >= MinAddress; Address -= PAGE_SIZE) {
     Check = 0;
     ReadMemory (Address, &Check, sizeof (Check), &BytesRead);
-    if ((BytesRead == sizeof (Check)) && (Check == Magic)) {
+    if (BytesRead != sizeof (Check)) {
+      break;
+    }
+
+    if ((Check & 0xFFFF) == Magic) {
       sprintf_s (&Command[0], sizeof (Command), ".imgscan /l /r %I64x %I64x", Address, Address + 0xFFF);
       g_ExtControl->Execute (
                       DEBUG_OUTCTL_ALL_CLIENTS,
                       &Command[0],
                       DEBUG_EXECUTE_DEFAULT
                       );
 
+      Result = S_OK;
+      break;
+    } else if (Check == ElfMagic) {
+      sprintf_s (&Command[0], sizeof (Command), "!uefiext.elf %I64x", Address);
+      g_ExtControl->Execute (
+                      DEBUG_OUTCTL_ALL_CLIENTS,
+                      &Command[0],
+                      DEBUG_EXECUTE_DEFAULT
+                      );
+
       Result = S_OK;
       break;
     }
@@ -238,3 +253,101 @@ findall (
   EXIT_API ();
   return S_OK;
 }
+
+#pragma pack (push, 1)
+typedef struct _ELF_HEADER_64 {
+  unsigned char    e_ident[16]; // 0x74 + ELF
+  UINT16           e_type;
+  UINT16           e_machine;
+  UINT32           e_version;
+  UINT64           e_entry;
+  UINT64           e_phoff;
+  UINT64           e_shoff;
+  UINT32           e_flags;
+  UINT16           e_ehsize;
+  UINT16           e_phentsize;
+  UINT16           e_phnum;
+  UINT16           e_shentsize;
+  UINT16           e_shnum;
+  UINT16           e_shstrndx;
+} ELF_HEADER_64;
+C_ASSERT (sizeof (ELF_HEADER_64) == 64);
+
+typedef struct _ELF_SECTION_64 {
+  UINT32    sh_name;
+  UINT16    e_type;
+  UINT16    e_machine;
+  UINT32    e_version;
+  UINT64    e_entry;
+  UINT64    e_phoff;
+  UINT64    e_shoff;
+  UINT32    e_flags;
+  UINT16    e_ehsize;
+  UINT16    e_phentsize;
+  UINT16    e_phnum;
+  UINT16    e_shentsize;
+  UINT16    e_shnum;
+  UINT16    e_shstrndx;
+} ELF_SECTION_64;
+
+#pragma pack (pop)
+
+HRESULT CALLBACK
+elf (
+  PDEBUG_CLIENT4  Client,
+  PCSTR           args
+  )
+{
+  ULONG64         Address;
+  ELF_HEADER_64   Header = { 0 };
+  ELF_SECTION_64  *Section;
+  ULONG           BytesRead = 0;
+
+  INIT_API ();
+
+  if (strlen (args) == 0) {
+    dprintf ("Usage: !uefiext.elf [Address]\n");
+    return ERROR_INVALID_PARAMETER;
+  }
+
+  Address = GetExpression (args);
+  if ((Address == 0) || (Address == (-1))) {
+    dprintf ("Invalid address!\n");
+    dprintf ("Usage: !uefiext.elf [Address]\n");
+    return ERROR_INVALID_PARAMETER;
+  }
+
+  ReadMemory (Address, &Header, sizeof (Header), &BytesRead);
+  if (BytesRead != sizeof (Header)) {
+    dprintf ("Failed to read header!\n");
+    return ERROR_BAD_ARGUMENTS;
+  }
+
+  if ((Header.e_ident[0] != 0x7F) || (Header.e_ident[1] != 'E') || (Header.e_ident[2] != 'L') || (Header.e_ident[3] != 'F')) {
+    dprintf ("Invalid ELF header! Magic did not match.\n");
+    return ERROR_INVALID_DATA;
+  }
+
+  dprintf ("ELF Header @ %llx\n", Address);
+  dprintf ("------------------------------------\n");
+  dprintf ("Type                     0x%x\n", Header.e_type);
+  dprintf ("Machine                  0x%x\n", Header.e_machine);
+  dprintf ("Version                  0x%x\n", Header.e_version);
+  dprintf ("Entry                    0x%llx\n", Header.e_entry);
+  dprintf ("Program Table Offset     0x%llx\n", Header.e_phoff);
+  dprintf ("Section Table Offset     0x%llx\n", Header.e_shoff);
+  dprintf ("Flags                    0x%x\n", Header.e_flags);
+  dprintf ("Header Size              0x%x\n", Header.e_ehsize);
+  dprintf ("Program Header Size      0x%x\n", Header.e_phentsize);
+  dprintf ("Program Header Num       0x%x\n", Header.e_phnum);
+  dprintf ("Section Header Size      0x%x\n", Header.e_shentsize);
+  dprintf ("Section Header Num       0x%x\n", Header.e_shnum);
+  dprintf ("Section Names Index      0x%x\n", Header.e_shstrndx);
+  dprintf ("------------------------------------\n\n");
+
+  // Print sections.
+  Section = (ELF_SECTION_64 *)(Address + Header.e_phoff);
+
+  EXIT_API ();
+  return S_OK;
+}

UefiDbgExt/swdebug.cpp

@@ -44,7 +44,12 @@ modulebreak (
 
   INIT_API ();
 
-  sprintf_s (Command, sizeof (Command), ".exdicmd target:0:b%s", args);
+  if (RUST == gUefiEnv) {
+    sprintf_s (Command, sizeof (Command), ".exdicmd target:0:mod break %s", args);
+  } else {
+    sprintf_s (Command, sizeof (Command), ".exdicmd target:0:b%s", args);
+  }
+
   g_ExtControl->Execute (
                   DEBUG_OUTCTL_ALL_CLIENTS,
                   Command,
@@ -138,3 +143,20 @@ reboot (
   EXIT_API ();
   return S_OK;
 }
+
+HRESULT CALLBACK
+monitor (
+  PDEBUG_CLIENT4  Client,
+  PCSTR           args
+  )
+{
+  PSTR  Response;
+
+  INIT_API ();
+
+  Response = MonitorCommandWithOutput (Client, args);
+  dprintf ("%s\n", Response);
+
+  EXIT_API ();
+  return S_OK;
+}