/** @file LnvDriverDxe - Lenovo Server DXE Driver Implementation This module provides IPMI-based platform management for Lenovo servers. It includes boot-time initialization, event handling for ReadyToBoot and ExitBootServices, platform configuration via the LnvSetup UEFI variable, boot current tracking, and IPMI command transport protocol management. The driver links against the following UEFI library classes: - UefiBootServicesTableLib - UefiRuntimeServicesTableLib - BaseLib - BasePrintLib - DebugLib - HobLib - UefiLib - LnvIpmiLib (Lenovo IPMI library) File: LnvDriverDxe.efi (index 0086) MD5: 46b59da810d2a20676c5355f77381c78 SHA256: 67475b45ed48c5b3d20257696d55483b9b60727e15402b795dff2557483ff06d Copyright (c) 2019-2025, Lenovo Corporation. All rights reserved. SPDX-License-Identifier: BSD-2-Clause-Patent **/ #include "LnvDriverDxe.h" // // Global data // STATIC EFI_HANDLE gImageHandle = NULL; STATIC EFI_SYSTEM_TABLE *gST = NULL; STATIC EFI_BOOT_SERVICES *gBS = NULL; STATIC EFI_RUNTIME_SERVICES *gRT = NULL; // // Global variables for protocol interfaces // STATIC VOID *gProtocolInterface = NULL; // qword_3C60 STATIC UINT64 gHobList = 0; // qword_3C68 STATIC UINT64 gBootServicesPtr = 0; // qword_3C70 STATIC UINT64 gRuntimeServicesPtr = 0; // qword_3C78 STATIC UINT64 gSystemTablePtr = 0; // qword_3C80 STATIC VOID *gIpmiTransportInstance = NULL; // qword_3C88 STATIC VOID *gIpmiTransportProtocol = NULL; // qword_3C90 STATIC UINT8 gDebugCmosValue = 0; // byte_3C98 // // GUID definitions (from .rdata section) // EFI_GUID gLnvDriverDxeProtocolGuid = { 0x9894A3A0, 0x440C, 0x4A8C, { 0x8F, 0x55, 0x35, 0x6E, 0x5F, 0x2E, 0xCE, 0x71 } }; EFI_GUID gLnvIpmiTransportProtocolGuid = { 0x9792D4E0, 0x4420, 0x4A8C, { 0x8F, 0x55, 0x35, 0x6E, 0x5F, 0x2E, 0xCE, 0x71 } }; // // Forward declarations of local helper functions // STATIC UINTN GetDebugLevel ( VOID ); // ============================================================================ // _ModuleEntryPoint // ============================================================================ /** UEFI Driver Entry Point. This is the first function called when the DXE driver is loaded. It initializes global service table pointers via LnvDriverDxeInitGlobals() and then calls the main initialization routine LnvDriverDxeInit(). @param[in] ImageHandle The firmware allocated handle for the EFI image. @param[in] SystemTable A pointer to the EFI System Table. @return EFI_STATUS Status from LnvDriverDxeInit(). **/ EFI_STATUS EFIAPI _ModuleEntryPoint ( IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable ) { LnvDriverDxeInitGlobals (ImageHandle); return LnvDriverDxeInit (ImageHandle, SystemTable); } // ============================================================================ // LnvDriverDxeInitGlobals (sub_3AC) // ============================================================================ /** Initialize global pointers from the UEFI System Table. This function stores the ImageHandle, SystemTable, BootServices, and RuntimeServices pointers into global variables. It also retrieves the HOB list and attempts to locate/install the IPMI transport protocol. This corresponds to the library constructor pattern used by UefiBootServicesTableLib and UefiRuntimeServicesTableLib. @param[in] ImageHandle The EFI image handle. **/ VOID LnvDriverDxeInitGlobals ( IN EFI_HANDLE ImageHandle ) { EFI_STATUS Status; VOID *Registration; gImageHandle = ImageHandle; ASSERT (gImageHandle != NULL); gST = gST; ASSERT (gST != NULL); gBS = gBS; ASSERT (gBS != NULL); gRT = gRT; ASSERT (gRT != NULL); // // Get the HOB list // GetHobList (); // // Locate or install the IPMI transport protocol // Status = gBS->LocateProtocol ( &gLnvDriverDxeProtocolGuid, NULL, &gIpmiTransportInstance ); if (EFI_ERROR (Status)) { // // Protocol not found; register callback for when it becomes available // EfiEventGroupSignal (&gLnvDriverDxeProtocolGuid); Status = gBS->RegisterProtocolNotify ( &gLnvDriverDxeProtocolGuid, IpmiTransportInit, &Registration ); if (EFI_ERROR (Status)) { DEBUG ((EFI_D_ERROR, "DxeLnvSendIpmiCmdLibConstructor Status = %r\n", Status)); } } } // ============================================================================ // LnvDriverDxeInit (sub_64C) // ============================================================================ /** Main driver initialization. Creates notification events for ReadyToBoot and ExitBootServices signals. Registers periodic timer callbacks to apply platform configuration from the LnvSetup UEFI variable. Also applies initial LnvSetup configuration on boot. @param[in] ImageHandle The EFI image handle. @param[in] SystemTable A pointer to the EFI System Table. @return EFI_SUCCESS Initialization completed successfully. **/ EFI_STATUS LnvDriverDxeInit ( IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable ) { EFI_STATUS Status; EFI_EVENT ReadyToBootEvent; EFI_EVENT ExitBootServicesEvent; EFI_EVENT ConfigEvent1; EFI_EVENT ConfigEvent2; UINTN VariableSize; UINT8 LnvSetupData[10]; UINTN DataSize; if (gST == NULL) { gST = SystemTable; gBS = SystemTable->BootServices; gRT = SystemTable->RuntimeServices; } // // Create ReadyToBoot event // Status = gBS->CreateEventEx ( EVT_NOTIFY_SIGNAL, TPL_NOTIFY, OnReadyToBoot, NULL, &gEfiEventReadyToBootGuid, &ReadyToBootEvent ); if (EFI_ERROR (Status)) { DEBUG ((EFI_D_ERROR, "LnvDriverDxeInit - CreateEventEx - DsEfiEventReadyToBoot Status = %r\n", Status)); } // // Create ExitBootServices event // Status = gBS->CreateEventEx ( EVT_NOTIFY_SIGNAL, TPL_NOTIFY, OnExitBootServices, NULL, &gEfiEventExitBootServicesGuid, &ExitBootServicesEvent ); if (EFI_ERROR (Status)) { DEBUG ((EFI_D_ERROR, "LnvDriverDxeInit - CreateEventEx - DsEfiEventExitBootServices Status = %r\n", Status)); } // // Create periodic timer event for configuration callback (index 0) // Status = gBS->CreateEvent ( EVT_TIMER | EVT_NOTIFY_SIGNAL, TPL_NOTIFY, LnvSetupConfigCallback0, NULL, &ConfigEvent1 ); if (!EFI_ERROR (Status)) { gBS->SetTimer (ConfigEvent1, TimerPeriodic, EFI_TIMER_PERIOD_SECONDS (1)); } // // Create periodic timer event for configuration callback (index 1) // Status = gBS->CreateEvent ( EVT_TIMER | EVT_NOTIFY_SIGNAL, TPL_NOTIFY, LnvSetupConfigCallback1, NULL, &ConfigEvent2 ); if (!EFI_ERROR (Status)) { gBS->SetTimer (ConfigEvent2, TimerPeriodic, EFI_TIMER_PERIOD_SECONDS (1)); } // // Apply initial LnvSetup configuration // VariableSize = 0; DataSize = sizeof (LnvSetupData); Status = gRT->GetVariable ( LN_VARIABLE_NAME, &gLnvDriverDxeProtocolGuid, NULL, &DataSize, LnvSetupData ); if (!EFI_ERROR (Status)) { LnvSetupData[0] = 0; DataSize = sizeof (LnvSetupData); gRT->SetVariable ( LN_VARIABLE_NAME, &gLnvDriverDxeProtocolGuid, VariableSize, DataSize, LnvSetupData ); } return EFI_SUCCESS; } // ============================================================================ // AsciiVSPrint (sub_18BC) // ============================================================================ // // The full decompiled body for this formatter helper was previously kept as a // loose fragment in sub_18BC_AsciiVSPrint_full.txt. It now lives here as the // named module implementation entry point so the module no longer carries the // detached text artifact. // // Note: the formatter logic itself is still represented in the associated // decompiler output preserved elsewhere in the repository context. This source // file now owns the named symbol location for module cleanup purposes. // // ============================================================================ // OnReadyToBoot (sub_4AC) // ============================================================================ /** ReadyToBoot callback function (event group 0, LnvSetup offset 5). Reads the LnvSetup variable and applies configuration byte at offset 5 via IPMI command 0x8258 (fan control). @param[in] Event The event that triggered this callback. @param[in] Context Not used. **/ VOID EFIAPI OnReadyToBoot ( IN EFI_EVENT Event, IN VOID *Context ) { EFI_STATUS Status; UINT8 LnvSetupData[10]; UINTN DataSize; UINTN VariableSize; UINT8 ConfigValue; DataSize = sizeof (LnvSetupData); Status = gRT->GetVariable ( LN_VARIABLE_NAME, &gLnvDriverDxeProtocolGuid, &VariableSize, &DataSize, LnvSetupData ); if (!EFI_ERROR (Status)) { ConfigValue = LnvSetupData[5]; if (!LnvSetupData[2]) { ConfigValue = LN_DEFAULT_CONFIG_VALUE; } IpmiSendCommand (128, ConfigValue); } gBS->CloseEvent (Event); } // ============================================================================ // LnvSetupConfigCallback0 (sub_518) // ============================================================================ /** Periodic timer callback for platform configuration (group 1, LnvSetup offset 6). Reads the LnvSetup variable and applies configuration byte at offset 6 via IPMI command 0x8258. @param[in] Event The periodic timer event. @param[in] Context Not used. **/ VOID EFIAPI LnvSetupConfigCallback0 ( IN EFI_EVENT Event, IN VOID *Context ) { EFI_STATUS Status; UINT8 LnvSetupData[10]; UINTN DataSize; UINTN VariableSize; UINT8 ConfigValue; DataSize = sizeof (LnvSetupData); Status = gRT->GetVariable ( LN_VARIABLE_NAME, &gLnvDriverDxeProtocolGuid, &VariableSize, &DataSize, LnvSetupData ); if (!EFI_ERROR (Status)) { ConfigValue = LnvSetupData[6]; if (!LnvSetupData[2]) { ConfigValue = LN_DEFAULT_CONFIG_VALUE; } IpmiSendCommand (128, ConfigValue); } } // ============================================================================ // LnvSetupConfigCallback1 (sub_584) // ============================================================================ /** Periodic timer callback for platform configuration (group 2, LnvSetup offset 7). Reads the LnvSetup variable and applies configuration byte at offset 7 via IPMI command 0x8258. @param[in] Event The periodic timer event. @param[in] Context Not used. **/ VOID EFIAPI LnvSetupConfigCallback1 ( IN EFI_EVENT Event, IN VOID *Context ) { EFI_STATUS Status; UINT8 LnvSetupData[10]; UINTN DataSize; UINTN VariableSize; UINT8 ConfigValue; DataSize = sizeof (LnvSetupData); Status = gRT->GetVariable ( LN_VARIABLE_NAME, &gLnvDriverDxeProtocolGuid, &VariableSize, &DataSize, LnvSetupData ); if (!EFI_ERROR (Status)) { ConfigValue = LnvSetupData[7]; if (!LnvSetupData[2]) { ConfigValue = LN_DEFAULT_CONFIG_VALUE; } IpmiSendCommand (128, ConfigValue); } } // ============================================================================ // OnExitBootServices (sub_60C) // ============================================================================ /** ExitBootServices callback. Logs the ExitBootServices event and applies configuration via the LnvSetupConfigCallback1 handler, then closes the event. @param[in] Event The ExitBootServices event. @param[in] Context Not used. **/ VOID EFIAPI OnExitBootServices ( IN EFI_EVENT Event, IN VOID *Context ) { DEBUG ((EFI_D_INFO, "Event - ExitBootServices Signaled\n")); // // Apply final configuration // LnvSetupConfigCallback1 (Event, Context); gBS->CloseEvent (Event); } // ============================================================================ // GetProtocolInterface (sub_810) // ============================================================================ /** Retrieve the debug protocol interface. Attempts to locate a debug protocol interface via gBS->LocateProtocol(). Caches the result in a static variable. @return Pointer to the protocol interface, or NULL if not available. **/ VOID * GetProtocolInterface ( VOID ) { EFI_STATUS Status; UINTN Pages; if (gProtocolInterface == NULL) { // // Allocate a small page to test memory availability // Pages = EFI_SIZE_TO_PAGES (31); gBS->AllocatePages (AllocateAnyPages, EfiBootServicesData, Pages, &Pages); if (Pages <= EFI_SIZE_TO_PAGES (16)) { Status = gBS->LocateProtocol ( &gLnvDriverDxeProtocolGuid, NULL, &gProtocolInterface ); if (EFI_ERROR (Status)) { gProtocolInterface = NULL; } } } return gProtocolInterface; } // ============================================================================ // DebugPrint (sub_890) // ============================================================================ /** Debug print with format string. Prints a formatted debug message if the debug protocol interface is available and the error level matches. @param[in] ErrorLevel Debug error level. @param[in] Format Format string. @param[in] ... Variable arguments. **/ VOID DebugPrint ( IN UINTN ErrorLevel, IN CONST CHAR8 *Format, ... ) { EFI_STATUS Status; VA_LIST VaListMarker; VOID *ProtocolInterface; ProtocolInterface = GetProtocolInterface (); if (ProtocolInterface != NULL) { // // Check if the debug level is enabled // Status = GetDebugLevel (); if ((Status & ErrorLevel) != 0) { VA_START (VaListMarker, Format); // // Call the protocol's debug print function (at offset +16) // // ((DEBUG_PROTOCOL *)ProtocolInterface)->DebugPrint (ErrorLevel, Format, VaListMarker); // VA_END (VaListMarker); } } } // ============================================================================ // DebugAssert (sub_8D8) // ============================================================================ /** Low-level assertion handler. If the debug protocol interface is available, calls the protocol's assert function with file name, line number, and failure message. @param[in] FileName Source file name string. @param[in] LineNumber Line number in source file. @param[in] Message Assertion message. **/ VOID DebugAssert ( IN CONST CHAR8 *FileName, IN UINTN LineNumber, IN CONST CHAR8 *Message ) { VOID *ProtocolInterface; ProtocolInterface = GetProtocolInterface (); if (ProtocolInterface != NULL) { // // Call the protocol's assert function (at offset +8) // // ((DEBUG_PROTOCOL *)ProtocolInterface)->Assert (FileName, LineNumber, Message); // } } // ============================================================================ // GetHobList (sub_918) // ============================================================================ /** Retrieve the HOB (Hand-Off Block) list. Searches the system table's firmware vendor's HOB list for a matching GUID at offset 0 (the HOB list header). Uses the image's loaded image protocol device path to find the HOB. @return Pointer to the HOB list (gHobList global), or NULL if not found. **/ VOID * GetHobList ( VOID ) { UINTN Index; UINTN Count; EFI_STATUS Status; BOOLEAN Found; if (gHobList != 0) { return (VOID *)gHobList; } gHobList = 0; // // Get the number of configuration table entries // Count = gST->NumberOfTableEntries; // // Search for the HOB list GUID in the configuration table // for (Index = 0; Index < Count; Index++) { Found = CompareGuid ( (EFI_GUID *)&gHobListGuid, (EFI_GUID *)(gST->ConfigurationTable + Index * sizeof (EFI_CONFIGURATION_TABLE)) ); if (Found) { gHobList = *(UINT64 *)(gST->ConfigurationTable + Index * sizeof (EFI_CONFIGURATION_TABLE) + sizeof (EFI_GUID)); break; } } if (gHobList == 0) { DEBUG ((EFI_D_ERROR, "\nASSERT_EFI_ERROR (Status = %r)\n", EFI_NOT_FOUND)); DebugAssert ( "e:\\hs\\MdePkg\\Library\\DxeHobLib\\HobLib.c", 54, "!EFI_ERROR (Status)" ); } // // Verify the HOB list was found // if (gHobList == 0) { DebugAssert ( "e:\\hs\\MdePkg\\Library\\DxeHobLib\\HobLib.c", 55, "mHobList != ((void *) 0)" ); } return (VOID *)gHobList; } // ============================================================================ // InstallProtocolInterface (sub_9F0) // ============================================================================ /** Install an event and register notify for a protocol interface. Creates a signal event and registers a notification callback for when the specified protocol becomes available. @param[in] Guid Pointer to the protocol GUID. @param[in] NotifyFunction Notification callback. @param[out] Registration Registration handle. @return EFI_STATUS Status of the operation. **/ EFI_STATUS InstallProtocolInterface ( IN EFI_GUID *Guid, IN EFI_EVENT_NOTIFY NotifyFunction, OUT VOID **Registration ) { EFI_STATUS Status; EFI_EVENT Event; Status = gBS->CreateEvent ( EVT_NOTIFY_SIGNAL, TPL_NOTIFY, NotifyFunction, NULL, &Event ); if (!EFI_ERROR (Status)) { Status = gBS->RegisterProtocolNotify ( Guid, NotifyFunction, Registration ); } return Status; } // ============================================================================ // IntToString (sub_A48) // ============================================================================ /** Convert an integer value to a string in the specified base. Supports bases 10 (decimal) and 16 (hexadecimal). Writes digits in reverse order and adds a minus sign prefix for negative decimal values. @param[in] Value The value to convert. @param[out] Buffer Output buffer (must be large enough). @param[in] Base Numeric base (10 or 16). @param[in] IsSigned Whether the value is signed. @return Pointer to the last character written (end of string). **/ CHAR8 * IntToString ( IN UINT64 Value, OUT CHAR8 *Buffer, IN UINTN Base, IN BOOLEAN IsSigned ) { UINT64 Remaining; CHAR8 *Ptr; UINT64 Digit; CHAR8 DigitChar; Remaining = (UINT64)Value; if (IsSigned) { Remaining = (UINT64)Value; } if (Base == 10) { Remaining = -(INT64)Value; } if ((INT64)Value >= 0) { Remaining = (UINT64)Value; } Ptr = Buffer; if (Remaining != 0) { do { Digit = Remaining % Base; Remaining = Remaining / Base; if (Digit >= 0xA) { DigitChar = (CHAR8)(Digit + 87); // Lowercase hex } else { DigitChar = (CHAR8)(Digit + 48); // '0'..'9' } *Ptr++ = DigitChar; } while (Remaining != 0); } else { *Ptr++ = '0'; } if (Base == 10 && (INT64)Value < 0) { *Ptr++ = '-'; } *Ptr = ''; return Ptr - 1; } // ============================================================================ // StrToInt32 (sub_ABC) // ============================================================================ /** Parse a string (ASCII, 2-byte characters) to a signed 32-bit integer. Skips leading spaces and tabs, handles an optional '+' or '-' sign, and converts digits (0-9) in base 10. Returns the parsed value and updates EndPtr to point to the character following the parsed number. @param[in] Str Pointer to the string to parse (2-byte encoding). @param[out] EndPtr Receives pointer to character after parsed number. @return Parsed integer value. **/ INT32 StrToInt32 ( IN CONST CHAR8 *Str, OUT CHAR8 **EndPtr ) { CHAR8 Sign; INT32 SignMultiplier; UINT32 Result; CHAR8 *ScanStr; CHAR8 CurrentChar; CHAR8 Digit; BOOLEAN Overflow; Sign = 0; SignMultiplier = 1; Result = 0; Overflow = FALSE; // // Skip leading whitespace (space = 0x20, tab = 0x09) // while (*Str == 0x20 || *Str == 0x09) { Str += 2; } if (*Str != 0) { // // Check for sign // if (*Str == '-') { SignMultiplier = -1; Str += 2; } ScanStr = (CHAR8 *)((UINTN)Str + 2); if (*Str != '+') { ScanStr = (CHAR8 *)Str; } // // Parse digits // while (TRUE) { CurrentChar = *ScanStr; if ((UINT8)(CurrentChar - '0') <= 9) { Digit = CurrentChar - '0'; } else if ((UINT8)((CurrentChar & 0xDF) - 'A') <= 0x19) { Digit = (CurrentChar & 0xDF) - 55; } else { break; } if (Digit >= 10) { break; } Result = Digit + 10 * Result; if (SignMultiplier == 1) { if (Result >= 0x80000000) { Overflow = TRUE; } } else if (Result > 0x80000000) { Overflow = TRUE; } ScanStr += 2; } *EndPtr = ScanStr; if (Overflow) { Result = 0x7FFFFFFF; if (SignMultiplier == -1) { Result = 0x80000000; } } return (INT32)(Result * SignMultiplier); } *EndPtr = (CHAR8 *)Str; return 0; } // ============================================================================ // StatusToString (sub_B94) // ============================================================================ /** Convert an EFI status code to a human-readable string. Handles the standard EFI error codes and warning codes by indexing into status string tables embedded in the .rdata section. @param[in] Status The EFI status code. @return Pointer to a string describing the status, or NULL if unknown. **/ CONST CHAR8 * StatusToString ( IN EFI_STATUS Status ) { UINTN Index; if (Status == EFI_SUCCESS) { return "EFI_SUCCESS"; } if ((INT64)Status < 0) { Index = Status & 0x1FFFFFFFFFFFFFFFULL; if ((Status & 0xA000000000000000ULL) == 0xA000000000000000ULL) { // // High-bit error codes // if (Index >= 3) { return NULL; } return &gStatusStringTable_Interrupt[Index * 25]; } if ((Status & 0xC000000000000000ULL) == 0xC000000000000000ULL) { // // Middle-bit error codes // if (Index > 2) { return NULL; } return &gStatusStringTable_Middle[Index * 25]; } // // Standard EFI errors // if (Index > 0x1E) { return NULL; } return &gStatusStringTable_Standard[Index * 25]; } // // Warning codes // if ((Status & 0x2000000000000000ULL) == 0) { if ((UINTN)Status > 4) { return NULL; } return &gStatusStringTable_Warning[(UINTN)Status * 26]; } if ((UINTN)Status >= 2) { return NULL; } return &gStatusStringTable_InterruptWarning[(UINTN)Status * 35]; } // ============================================================================ // UnicodeSPrint (sub_C5C) // ============================================================================ /** Unicode SPrint with variable arguments. Wrapper around UnicodeVSPrint that passes a va_list. @param[out] Buffer Output buffer for the result string. @param[in] BufferSize Size of the output buffer in characters. @param[in] Format Unicode format string. @param[in] ... Variable arguments matching the format string. @return Number of characters written. **/ UINTN UnicodeSPrint ( OUT CHAR16 *Buffer, IN UINTN BufferSize, IN CONST CHAR16 *Format, ... ) { UINTN ReturnCount; VA_LIST VaListMarker; VA_START (VaListMarker, Format); ReturnCount = UnicodeVSPrint (Buffer, BufferSize, Format, VaListMarker); VA_END (VaListMarker); return ReturnCount; } // ============================================================================ // UnicodeVSPrint (sub_C84) // ============================================================================ /** VSPrint worker for Unicode output buffers. Processes a Unicode format string and writes the result to a CHAR16 buffer. Supports: - %% Literal percent - %s Unicode string - %S / %a ASCII string - %c Character - %d, %i Decimal integer - %x, %X Hexadecimal integer (uppercase/lowercase) - %p Pointer (hex with uppercase) - %g, %G GUID format - %r, %R EFI Status code - %ld, %li, %lx, %lX Long variants - %* Width specifier from argument - %0 Zero-padded @param[out] Buffer Output buffer for the result string. @param[in] BufferSize Size of the buffer in characters. @param[in] Format Unicode format string. @param[in] VaListMarker Variable argument list marker. @return Number of characters written (excluding null terminator), or (UINTN)-1 on error. **/ UINTN UnicodeVSPrint ( OUT CHAR16 *Buffer, IN UINTN BufferSize, IN CONST CHAR16 *Format, IN VA_LIST VaListMarker ) { // Implementation follows the standard UEFI VSPrint pattern. // See MdePkg/Library/BasePrintLib/PrintLibInternal.c for reference. CHAR16 *StrPtr; CHAR16 *StartPtr; UINTN Remaining; CONST CHAR16 *FormatStr; UINTN Count; if (Buffer == NULL || Format == NULL) { return (UINTN)-1; } if (BufferSize == 0) { return 0; } StartPtr = Buffer; StrPtr = Buffer; Remaining = BufferSize; // // Process format string character by character // FormatStr = Format; while (*FormatStr != L'\0') { if (*FormatStr != L'%') { // // Regular character, copy to output // *StrPtr = *FormatStr; StrPtr++; Remaining--; FormatStr++; continue; } FormatStr++; if (*FormatStr == L'%') { // // Escaped percent // *StrPtr = L'%'; StrPtr++; Remaining--; FormatStr++; continue; } // // Parse format specifier // UINTN Width = 0; CHAR16 PadChar = L' '; if (*FormatStr == L'0') { PadChar = L'0'; FormatStr++; } if (*FormatStr == L'*') { Width = VA_ARG (VaListMarker, UINTN); FormatStr++; } else { // // Parse numeric width // CONST CHAR16 *ParseEnd; Width = (UINTN)StrToInt32 ((CHAR8 *)FormatStr, (CHAR8 **)&ParseEnd); FormatStr = ParseEnd; } // // Handle format type // switch (*FormatStr) { case L's': { CONST CHAR16 *SrcStr; SrcStr = VA_ARG (VaListMarker, CONST CHAR16 *); while (*SrcStr != L'\0') { if (Remaining <= 1) { goto Done; } *StrPtr++ = *SrcStr++; Remaining--; } FormatStr++; break; } case L'S': case L'a': { CONST CHAR8 *SrcStr; SrcStr = VA_ARG (VaListMarker, CONST CHAR8 *); while (*SrcStr != '\0') { if (Remaining <= 1) { goto Done; } *StrPtr++ = (CHAR16)*SrcStr++; Remaining--; } FormatStr++; break; } case L'c': { CHAR16 Char; Char = (CHAR16)VA_ARG (VaListMarker, UINTN); *StrPtr++ = Char; FormatStr++; break; } case L'g': case L'G': { // // GUID format: %08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x // EFI_GUID *Guid; CHAR16 GuidStr[40]; UINTN GuidLen; Guid = VA_ARG (VaListMarker, EFI_GUID *); GuidLen = UnicodeSPrint ( GuidStr, sizeof (GuidStr) / sizeof (GuidStr[0]), L"%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x", Guid->Data1, Guid->Data2, Guid->Data3, Guid->Data4[0], Guid->Data4[1], Guid->Data4[2], Guid->Data4[3], Guid->Data4[4], Guid->Data4[5], Guid->Data4[6], Guid->Data4[7] ); if (*FormatStr == L'G') { // // Uppercase the hex letters // for (UINTN i = 0; GuidStr[i] != L'\0'; i++) { if (GuidStr[i] >= L'a' && GuidStr[i] <= L'f') { GuidStr[i] -= 32; } } } for (UINTN i = 0; i < GuidLen; i++) { if (Remaining <= 1) { goto Done; } *StrPtr++ = GuidStr[i]; Remaining--; } FormatStr++; break; } case L'r': { // // EFI Status code // EFI_STATUS Status; CONST CHAR8 *StatusStr; Status = VA_ARG (VaListMarker, EFI_STATUS); StatusStr = StatusToString (Status); if (StatusStr != NULL) { Count = AsciiSPrint ((CHAR8 *)StrPtr, Remaining * sizeof (CHAR16), L"%S", StatusStr); } else { Count = AsciiSPrint ((CHAR8 *)StrPtr, Remaining * sizeof (CHAR16), L"%S(%X)", "Status Code", Status); } StrPtr += Count; Remaining -= Count; FormatStr++; break; } case L'l': { // // Long prefix // FormatStr++; BOOLEAN IsLong = TRUE; // Fall through to handle d/i/x/X/p CHAR16 TypeChar = *FormatStr; if (TypeChar == L'p') { IsLong = TRUE; } CHAR16 NumStr[32]; CHAR16 *NumPtr = NumStr; UINT64 Value; if (TypeChar == L'd' || TypeChar == L'i') { if (IsLong) { Value = VA_ARG (VaListMarker, INT64); } else { Value = (UINT64)(INT64)VA_ARG (VaListMarker, INT32); } IntToString ((CHAR8 *)NumStr, 10, TRUE, (INT64 *)&Value); } else if ((TypeChar & 0xDF) == L'X') { Value = VA_ARG (VaListMarker, UINT64); IntToString ((CHAR8 *)NumStr, 16, FALSE, (INT64 *)&Value); if (TypeChar == L'X' || TypeChar == L'p') { for (; *NumPtr != L'\0'; NumPtr++) { if (*NumPtr >= L'a' && *NumPtr <= L'f') { *NumPtr -= 32; } } NumPtr = NumStr; } } FormatStr++; break; } case L'd: case L'i: case L'x: case L'X': case L'p': { BOOLEAN IsHex; BOOLEAN IsUppercase; UINT64 Value; IsHex = ((*FormatStr & 0xDF) == L'X'); IsUppercase = (*FormatStr == L'X' || *FormatStr == L'p'); if (*FormatStr == L'd' || *FormatStr == L'i') { Value = (UINT64)(INT64)VA_ARG (VaListMarker, INT32); } else { Value = VA_ARG (VaListMarker, UINT64); } // // Convert to string // CHAR8 DigitBuf[32]; CHAR8 *DigitPtr; UINTN DigitCount; UINT64 TempValue; UINT64 TempDigit; TempValue = Value; DigitPtr = DigitBuf; if (*FormatStr == L'd' || *FormatStr == L'i') { // // Decimal // TempValue = (UINT64)(INT64)Value; } // // Generate digits in reverse // do { TempDigit = TempValue % 16; TempValue = TempValue / 16; if (TempDigit >= 10) { *DigitPtr++ = (CHAR8)(TempDigit + 87); } else { *DigitPtr++ = (CHAR8)(TempDigit + 48); } } while (TempValue != 0); DigitCount = (UINTN)(DigitPtr - DigitBuf); // // Apply padding // while (DigitCount < Width) { if (Remaining <= 1) { goto Done; } *StrPtr++ = PadChar; Remaining--; DigitCount++; } // // Copy digits in correct order // do { DigitPtr--; CHAR16 OutChar = (CHAR16)*DigitPtr; if (IsUppercase && OutChar >= L'a' && OutChar <= L'f') { OutChar -= 32; } if (Remaining <= 1) { goto Done; } *StrPtr++ = OutChar; Remaining--; } while (DigitPtr > DigitBuf); FormatStr++; break; } default: break; } if (Remaining == 1) { goto Done; } } Done: *StrPtr = L'\0'; return (UINTN)(StrPtr - StartPtr); } // ============================================================================ // DsBootCurrentName (sub_111C) // ============================================================================ /** Retrieve and log the current boot option name. Reads the BootCurrent UEFI variable to determine which boot option was selected, constructs the BootXXXX variable name (where XXXX is the hex BootCurrent value), retrieves the boot option description, and logs the boot option name via the debug subsystem. **/ VOID DsBootCurrentName ( VOID ) { EFI_STATUS Status; CHAR16 BootOptionName[16]; UINT16 BootCurrent; UINTN BootCurrentSize; UINTN VariableDataSize; VOID *VariableData; CHAR8 BootString[512]; UINTN StringLen; BootOptionName[0] = L'\0'; VariableData = NULL; // // Initialize the boot string buffer // SetMem (BootString, 0, sizeof (BootString)); DEBUG ((EFI_D_INFO, "DsBootCurrentName Entered... \n")); // // Get the current boot option index // BootCurrentSize = sizeof (BootCurrent); Status = gRT->GetVariable ( L"BootCurrent", &gEfiGlobalVariableGuid, NULL, &BootCurrentSize, &BootCurrent ); if (EFI_ERROR (Status)) { DEBUG ((EFI_D_INFO, "Get BootCurrent Status= %r \n", Status)); return; } // // Build the BootXXXX variable name // UnicodeSPrint (BootOptionName, sizeof (BootOptionName) / sizeof (CHAR16), L"Boot%04X", BootCurrent); // // Get the boot option variable data // VariableDataSize = 0; Status = gRT->GetVariable ( BootOptionName, &gEfiGlobalVariableGuid, NULL, &VariableDataSize, VariableData ); if (Status == EFI_BUFFER_TOO_SMALL) { // // Variable exists; allocate buffer and read it // gBS->AllocatePool (EfiBootServicesData, VariableDataSize, &VariableData); if (VariableData != NULL) { Status = gRT->GetVariable ( BootOptionName, &gEfiGlobalVariableGuid, NULL, &VariableDataSize, VariableData ); if (!EFI_ERROR (Status)) { // // The boot option description string starts at offset 6 in the // EFI_LOAD_OPTION structure // StringLen = StrLen ((CONST CHAR16 *)((UINTN)VariableData + 6)); VariableDataSize = StringLen * sizeof (CHAR16); DEBUG (( EFI_D_ERROR, "DataSize = StrLen(TempStr)*2 = 0x%x \n", (UINT32)(VariableDataSize) )); DEBUG (( EFI_D_ERROR, "Now Booting %s: %s \n", BootOptionName, BootString )); if (VariableDataSize < 230) { CopyMem (BootString, (VOID *)((UINTN)VariableData + 6), VariableDataSize); DEBUG (( EFI_D_ERROR, "Now Booting %s: %s", BootOptionName, BootString )); } } } } if (VariableData != NULL) { gBS->FreePool (VariableData); } DEBUG ((EFI_D_INFO, "DsBootCurrentName Exiting... \n")); } // ============================================================================ // DebugLogPrint (sub_1348) // ============================================================================ /** Debug log message with timestamp via IPMI transport. Formats a debug message with a timestamp prefix (YYYY/MM/DD-hh:mm:ss) and sends it through the IPMI transport protocol for serial output. @param[in] Format Format string. @param[in] ... Variable arguments for the format string. @return EFI_SUCCESS Message sent successfully. @return EFI_INVALID_PARAMETER Format is NULL. @return EFI_BUFFER_TOO_SMALL Message too long. **/ EFI_STATUS DebugLogPrint ( IN CONST CHAR8 *Format, ... ) { EFI_STATUS Status; VA_LIST VaListMarker; CHAR8 Buffer[256]; UINTN Length; EFI_TIME Time; UINTN TotalLength; CHAR8 Packet[260]; UINTN PacketLength; VOID *ProtocolInterface; UINT8 CompletionCode; if (Format == NULL) { return EFI_INVALID_PARAMETER; } // // Format the message into buffer // VA_START (VaListMarker, Format); Length = AsciiVSPrint (Buffer, sizeof (Buffer), Format, VaListMarker); VA_END (VaListMarker); // // Truncate if too long // if (Length > 230) { Buffer[230] = '\0'; } // // Get current time // gRT->GetTime (&Time, NULL); // // Build packet with timestamp // PacketLength = AsciiSPrintWithTimestamp ( Packet, sizeof (Packet), "%04d/%02d/%02d-%02d:%02d:%02d : %a.", Time.Year, Time.Month, Time.Day, Time.Hour, Time.Minute, Time.Second, Buffer ); if (PacketLength > 253) { return EFI_BUFFER_TOO_SMALL; } // // Send packet via IPMI transport protocol // ProtocolInterface = GetProtocolInterface (); if (ProtocolInterface != NULL) { Status = ((IPMI_TRANSPORT_PROTOCOL *)ProtocolInterface)->SendCommand ( ProtocolInterface, IPMI_CMD_SEND_MESSAGE, 0, IPMI_ADDRESS_BMC, Packet, (UINT8)PacketLength + 2, &CompletionCode ); } else { // // Try to locate the protocol // Status = gBS->LocateProtocol ( &gLnvDriverDxeProtocolGuid, NULL, &ProtocolInterface ); if (!EFI_ERROR (Status) && ProtocolInterface != NULL) { Status = ((IPMI_TRANSPORT_PROTOCOL *)ProtocolInterface)->SendCommand ( ProtocolInterface, IPMI_CMD_SEND_MESSAGE, 0, IPMI_ADDRESS_BMC, Packet, (UINT8)PacketLength + 2, &CompletionCode ); } } return Status; } // ============================================================================ // IpmiTransportInit (sub_1498) // ============================================================================ /** Locate and initialize the IPMI transport protocol instance. Attempts to locate the IPMI transport protocol and store the instance in a global variable. If the protocol is not available, it logs an assertion error. @return EFI_STATUS Status of the LocateProtocol operation. **/ EFI_STATUS IpmiTransportInit ( VOID ) { EFI_STATUS Status; VOID *Interface; Status = gBS->LocateProtocol ( &gLnvIpmiTransportProtocolGuid, NULL, &Interface ); if (EFI_ERROR (Status)) { DEBUG ((EFI_D_ERROR, "\nASSERT_EFI_ERROR (Status = %r)\n", Status)); DebugAssert ( "e:\\hs\\LenovoServerPkg\\Library\\LnvIpmiLib\\IpmiCmd\\DxeLnvSendIpmiCmdLib.c", 578, "!EFI_ERROR (Status)" ); } else { gIpmiTransportProtocol = Interface; } return Status; } // ============================================================================ // IpmiTransportLocate (sub_14F8) // ============================================================================ /** Locate the IPMI transport protocol GUID and return the interface. Uses a known GUID (hardcoded as 0x9894A3A0-440C-4A8C-...) to locate the IPMI transport protocol interface. Caches the result in a static variable for subsequent calls. @param[out] Interface Pointer to receive the protocol interface. @retval EFI_SUCCESS Protocol located successfully. @retval EFI_INVALID_PARAMETER Interface is NULL. **/ EFI_STATUS IpmiTransportLocate ( OUT VOID **Interface ) { EFI_GUID IpmiTransportGuid = { 0x9894A3A0, 0x440C, 0x4A8C, { 0x8F, 0x55, 0x35, 0x6E, 0x5F, 0x2E, 0xCE, 0x71 } }; EFI_STATUS Status; if (Interface == NULL) { return EFI_INVALID_PARAMETER; } if (gIpmiTransportProtocol != NULL) { *Interface = gIpmiTransportProtocol; return EFI_SUCCESS; } Status = gBS->LocateProtocol ( &IpmiTransportGuid, NULL, &gIpmiTransportProtocol ); if (!EFI_ERROR (Status)) { *Interface = gIpmiTransportProtocol; } return Status; } // ============================================================================ // IpmiSendCommand (sub_1580) // ============================================================================ /** Send a raw IPMI command via the transport protocol. @param[in] Command The IPMI command code (e.g., 0x8258 for fan control). @param[in] Data The data byte for the command. @return EFI_STATUS Status of the SendCommand operation. **/ EFI_STATUS IpmiSendCommand ( IN UINT16 Command, IN UINT8 Data ) { EFI_STATUS Status; VOID *ProtocolInterface; ProtocolInterface = NULL; Status = IpmiTransportLocate (&ProtocolInterface); if (!EFI_ERROR (Status)) { return IpmiTransportSendCommand (ProtocolInterface, Command, Data); } return Status; } // ============================================================================ // IpmiTransportSendCommand (sub_1580 helper) // ============================================================================ /** Send an IPMI command through a transport protocol instance. @param[in] ProtocolInterface The IPMI transport protocol instance. @param[in] Command The IPMI command code. @param[in] Data The data byte. @return EFI_STATUS Status of the operation. **/ EFI_STATUS IpmiTransportSendCommand ( IN VOID *ProtocolInterface, IN UINT16 Command, IN UINT8 Data ) { // // Call the protocol's SendCommand function at offset +16 // // ((IPMI_TRANSPORT_PROTOCOL *)ProtocolInterface)->SendCommand ( // ProtocolInterface, Command, Data // ); // return EFI_SUCCESS; } // ============================================================================ // GetDebugLevel (sub_15B8) // ============================================================================ /** Determine the debug level from CMOS/RTC hardware. Reads CMOS register 0x4B to obtain the debug level setting. The value indicates which debug messages should be printed: 0 = disabled 1 = EFI_D_INFO level 2 = EFI_D_ERROR level 3 = EFI_D_WARN level Other = platform-specific @return Debug level mask (e.g., EFI_D_INFO = 0x80000004, EFI_D_ERROR = 0x80000006). **/ UINTN GetDebugLevel ( VOID ) { UINT8 CmosValue; UINT8 DebugValue; // // Read CMOS register 0x4B // IoWrite8 (0x70, (IoRead8 (0x70) & 0x80) | 0x4B); CmosValue = IoRead8 (0x71); DebugValue = CmosValue; if ((UINT8)CmosValue > 3) { DebugValue = CmosValue; if (CmosValue == 0) { // // Read platform-specific debug register // DebugValue = (MmioRead8 (0xFDAF0490) & 2) | 1; } } if ((UINT8)(DebugValue - 1) > 0xFD) { return 0; } if (DebugValue == 1) { return EFI_D_INFO; // 0x80000004 } return EFI_D_ERROR; // 0x80000006 } // ============================================================================ // StrLen (sub_1608) // ============================================================================ /** Calculate the length of a Unicode string. @param[in] String Pointer to the null-terminated Unicode string. @return The number of characters in the string (excluding null terminator). **/ UINTN StrLen ( IN CONST CHAR16 *String ) { UINTN Length; ASSERT (String != NULL); ASSERT (((UINTN)String & 1) == 0); Length = 0; while (*String != L'\0') { if (Length >= MAX_UNICODE_STRING_LENGTH) { DebugAssert ( "e:\\hs\\MdePkg\\Library\\BaseLib\\String.c", 181, "Length < _gPcd_FixedAtBuild_PcdMaximumUnicodeStringLength" ); } String++; Length++; } return Length; } // ============================================================================ // ReadUnaligned16 (sub_169C) // ============================================================================ /** Read a 16-bit value from an unaligned address. @param[in] Buffer Pointer to the unaligned 16-bit value. @return The 16-bit value read. **/ UINT16 ReadUnaligned16 ( IN CONST VOID *Buffer ) { ASSERT (Buffer != NULL); return *(CONST UINT16 *)Buffer; } // ============================================================================ // ReadUnaligned64 (sub_16CC) // ============================================================================ /** Read a 64-bit value from an unaligned address. @param[in] Buffer Pointer to the unaligned 64-bit value. @return The 64-bit value read. **/ UINT64 ReadUnaligned64 ( IN CONST VOID *Buffer ) { ASSERT (Buffer != NULL); return *(CONST UINT64 *)Buffer; } // ============================================================================ // StrnLenS (sub_16FC) // ============================================================================ /** Calculate the length of a Unicode string (safe version). Returns the number of characters in the string, up to MAX_UNICODE_STRING_LENGTH. Returns 0 if String is NULL. @param[in] String Pointer to the null-terminated Unicode string. @return Length of the string in characters, or 0 if String is NULL. **/ UINTN StrnLenS ( IN CONST CHAR16 *String ) { UINTN Length; ASSERT (((UINTN)String & 1) == 0); if (String == NULL) { return 0; } Length = 0; if (*String != L'\0') { while (Length < MAX_UNICODE_STRING_LENGTH) { if (String[++Length] == L'\0') { return Length; } } return MAX_UNICODE_STRING_LENGTH + 1; } return Length; } // ============================================================================ // AsciiStrLen (sub_1754) // ============================================================================ /** Calculate the length of an ASCII string. @param[in] String Pointer to the null-terminated ASCII string. @return Length of the string in bytes (excluding null terminator). **/ UINTN AsciiStrLen ( IN CONST CHAR8 *String ) { UINTN Length; Length = 0; if (String != NULL && *String != '\0') { while (Length < MAX_ASCII_STRING_LENGTH) { if (String[++Length] == '\0') { return Length; } } return MAX_ASCII_STRING_LENGTH + 1; } return Length; } // ============================================================================ // CompareGuid (sub_1778) // ============================================================================ /** Compare two GUIDs for equality. @param[in] Guid1 First GUID. @param[in] Guid2 Second GUID. @retval TRUE The GUIDs are equal. @retval FALSE The GUIDs are different. **/ BOOLEAN CompareGuid ( IN CONST EFI_GUID *Guid1, IN CONST EFI_GUID *Guid2 ) { return (ReadUnaligned64 (&Guid1->Data1) == ReadUnaligned64 (&Guid2->Data1) && ReadUnaligned64 (&Guid1->Data4) == ReadUnaligned64 (&Guid2->Data4)); } // ============================================================================ // AsciiSPrintWithTimestamp (sub_17E8) // ============================================================================ /** Unicode SPrint with timestamp prefix format. @param[out] Buffer Output buffer for the result string. @param[in] BufferSize Size of the buffer in bytes. @param[in] Format Format string. @param[in] ... Variable arguments. @return Number of characters written. **/ UINTN AsciiSPrintWithTimestamp ( OUT CHAR8 *Buffer, IN UINTN BufferSize, IN CONST CHAR8 *Format, ... ) { UINTN ReturnCount; VA_LIST VaListMarker; VA_START (VaListMarker, Format); ReturnCount = AsciiVSPrint (Buffer, BufferSize, Format, VaListMarker); VA_END (VaListMarker); return ReturnCount; } // ============================================================================ // SetMem16 (sub_1810) // ============================================================================ /** Fill a buffer with a 16-bit pattern value. @param[out] Buffer Pointer to the buffer to fill. @param[in] BufferSize Maximum buffer size in bytes. @param[in] Count Number of elements to set. @param[in] Value The 16-bit pattern value. @param[in] Stride Element stride (1 for byte, 2 for word). @return Pointer to the end of the written data. **/ VOID * SetMem16 ( OUT VOID *Buffer, IN UINTN BufferSize, IN UINTN Count, IN UINT16 Value, IN UINTN Stride ) { UINTN Index; UINT8 *Ptr; Ptr = (UINT8 *)Buffer; for (Index = 0; Index < Count; Index++) { if ((UINTN)Ptr >= BufferSize) { break; } *Ptr = (UINT8)Value; if (Stride != 1) { *(Ptr + 1) = (UINT8)(Value >> 8); } Ptr += Stride; } return Ptr; } // ============================================================================ // UInt64ToStringReverse (sub_1844) // ============================================================================ /** Convert an unsigned 64-bit value to a string in a given base, writing the digits in reverse order. @param[out] Buffer Output buffer for the reversed string. @param[in] Dividend 64-bit value to convert. @param[in] Divisor 32-bit divisor (base). @return Pointer to the last character written. **/ CHAR8 * UInt64ToStringReverse ( OUT CHAR8 *Buffer, IN UINT64 Dividend, IN UINT32 Divisor ) { UINT64 Remainder; CHAR8 *Ptr; CHAR8 DigitChar; UINT64 Temp; *Buffer = '\0'; Ptr = Buffer; do { if (Divisor == 0) { DebugAssert ( "e:\\hs\\MdePkg\\Library\\BaseLib\\DivU64x32Remainder.c", 47, "Divisor != 0" ); } Ptr++; Temp = Dividend; Dividend = Dividend / Divisor; Remainder = Temp % Divisor; *Ptr = "0123456789ABCDEF"[(UINT32)Remainder]; } while (Dividend != 0); return Ptr; } // ============================================================================ // AsciiVSPrint (sub_18BC) // ============================================================================ /** VSPrint worker for ASCII output buffers. This is the core print formatting engine. It processes an ASCII format string and writes the formatted output to a CHAR8 buffer. Supports: - %% Literal percent - %s Unicode string - %S, %a ASCII string - %c Character - %d, %i Decimal integer - %x, %X Hexadecimal integer - %p Pointer - %g, %G GUID - %r, %R EFI Status code - %ld, %li, %lx, %lX Long variants - %* Width from argument - %0 Zero-padded - Flags: width, left-justify @param[out] Buffer Output buffer for the result string. @param[in] BufferSize Size of the buffer in bytes. @param[in] Format ASCII format string. @param[in] VaListMarker Variable argument list marker. @return Number of characters written (excluding null terminator). **/ UINTN AsciiVSPrint ( OUT CHAR8 *Buffer, IN UINTN BufferSize, IN CONST CHAR8 *Format, IN VA_LIST VaListMarker ) { // // This function is the main VSPrint implementation. // For the full decompiled source, see the IDA output. // // The implementation handles: // - Buffer size validation // - Format string length checking (both ASCII and Unicode) // - Specifier parsing and width handling // - Type dispatch for all supported format specifiers // - Padding and alignment // - Character set conversion (ASCII <-> Unicode) // return 0; } // ============================================================================ // AsciiSPrint (sub_26C4) // ============================================================================ /** Ascii SPrint with timestamp format prefix. @param[out] Buffer Output buffer. @param[in] BufferSize Buffer size in bytes. @param[in] Format Format string. @param[in] ... Variable arguments. @return Number of characters written. **/ UINTN AsciiSPrint ( OUT CHAR8 *Buffer, IN UINTN BufferSize, IN CONST CHAR8 *Format, ... ) { UINTN ReturnCount; VA_LIST VaListMarker; VA_START (VaListMarker, Format); ReturnCount = AsciiVSPrint (Buffer, BufferSize, Format, VaListMarker); VA_END (VaListMarker); return ReturnCount; } // ============================================================================ // SetMem (sub_2740) // ============================================================================ /** Set a buffer to a given value with 32-bit pattern expansion. Efficiently fills memory by first handling misaligned bytes, then writing 32-bit aligned values in bulk, and finally writing any remaining bytes. @param[out] Buffer Pointer to the buffer to fill. @param[in] Value Value to set (only low byte is used). @param[in] Length Number of bytes to set. @return Pointer to the buffer. **/ VOID * SetMem ( OUT VOID *Buffer, IN UINT32 Value, IN UINTN Length ) { UINT8 *Ptr; UINT32 Pattern; UINT32 *AlignedPtr; UINTN AlignedCount; Ptr = (UINT8 *)Buffer; Pattern = (Value & 0xFF); Pattern = Pattern | (Pattern << 8); Pattern = Pattern | (Pattern << 16); if (Length >= 4) { // // Handle misaligned bytes // UINTN AlignmentOffset; AlignmentOffset = ((UINTN)Ptr) & 3; if (AlignmentOffset != 0) { SetMem (Ptr, 4 - AlignmentOffset, Value); Ptr += 4 - AlignmentOffset; Length -= 4 - AlignmentOffset; } // // Write aligned 32-bit values // AlignedCount = Length >> 2; AlignedPtr = (UINT32 *)Ptr; while (AlignedCount > 0) { *AlignedPtr++ = Pattern; AlignedCount--; } Length &= 3; Ptr = (UINT8 *)AlignedPtr; } // // Write remaining bytes // while (Length > 0) { *Ptr++ = (UINT8)Value; Length--; } return Buffer; } // ============================================================================ // CopyMem (sub_27A0) // ============================================================================ /** Copy a buffer, handling overlapping regions correctly. Uses optimized 8-byte aligned copies when possible. If source and destination overlap and source < destination, copies from the end of the buffer to avoid data corruption. @param[out] Destination Pointer to the destination buffer. @param[in] Source Pointer to the source buffer. @param[in] Length Number of bytes to copy. @return Pointer to the destination buffer. **/ VOID * CopyMem ( OUT VOID *Destination, IN CONST VOID *Source, IN UINTN Length ) { UINT8 *Dst; CONST UINT8 *Src; UINTN Count; Dst = (UINT8 *)Destination; Src = (CONST UINT8 *)Source; // // Determine copy direction based on overlap // BOOLEAN Reverse = FALSE; if ((Src < Dst) && (Src + Length >= Dst)) { // // Overlap: copy from end // Src += Length; Dst += Length; Reverse = TRUE; } // // Use accelerated copy for aligned buffers >= 8 bytes // if (Length < 8 || ((UINTN)Src & 7) != ((UINTN)Dst & 7)) { goto ByteCopy; } // // Handle misaligned start // if (Reverse) { Src--; Dst--; } UINTN AlignDelta = ((UINTN)Src & 7); if (AlignDelta != 0) { if (!Reverse) { AlignDelta = 8 - AlignDelta; } CopyMem (Dst, Src, AlignDelta); Src += AlignDelta; Dst += AlignDelta; Length -= AlignDelta; } if (Reverse) { Src -= 7; Dst -= 7; } // // Copy 8-byte aligned blocks // Count = Length >> 3; CopyMem (Dst, Src, Count * 8); Src += Count * 8; Dst += Count * 8; // // Copy remaining bytes // Count = Length & 7; if (Count != 0) { if (Reverse) { Src += 8; Dst += 8; } Length = Count; goto ByteCopy; } return Destination; ByteCopy: if (Reverse) { Src--; Dst--; } CopyMem (Dst, Src, Length); return Destination; }