audk/MdePkg/Library/BasePrintLib/PrintLibInternal.c

/** @file
  Print Library internal worker functions.

  Copyright (c) 2006 - 2008, 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.

**/

#include "PrintLibInternal.h"

#define WARNING_STATUS_NUMBER         4
#define ERROR_STATUS_NUMBER           24

GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 mHexStr[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};

GLOBAL_REMOVE_IF_UNREFERENCED CONST CHAR8 *mStatusString[] = {
  "Success",                      //  RETURN_SUCCESS                = 0
  "Warning Unknown Glyph",        //  RETURN_WARN_UNKNOWN_GLYPH     = 1
  "Warning Delete Failure",       //  RETURN_WARN_DELETE_FAILURE    = 2
  "Warning Write Failure",        //  RETURN_WARN_WRITE_FAILURE     = 3
  "Warning Buffer Too Small",     //  RETURN_WARN_BUFFER_TOO_SMALL  = 4
  "Load Error",                   //  RETURN_LOAD_ERROR             = 1  | MAX_BIT
  "Invalid Parameter",            //  RETURN_INVALID_PARAMETER      = 2  | MAX_BIT
  "Unsupported",                  //  RETURN_UNSUPPORTED            = 3  | MAX_BIT
  "Bad Buffer Size",              //  RETURN_BAD_BUFFER_SIZE        = 4  | MAX_BIT
  "Buffer Too Small",             //  RETURN_BUFFER_TOO_SMALL,      = 5  | MAX_BIT
  "Not Ready",                    //  RETURN_NOT_READY              = 6  | MAX_BIT
  "Device Error",                 //  RETURN_DEVICE_ERROR           = 7  | MAX_BIT
  "Write Protected",              //  RETURN_WRITE_PROTECTED        = 8  | MAX_BIT
  "Out of Resources",             //  RETURN_OUT_OF_RESOURCES       = 9  | MAX_BIT
  "Volume Corrupt",               //  RETURN_VOLUME_CORRUPTED       = 10 | MAX_BIT
  "Volume Full",                  //  RETURN_VOLUME_FULL            = 11 | MAX_BIT
  "No Media",                     //  RETURN_NO_MEDIA               = 12 | MAX_BIT
  "Media changed",                //  RETURN_MEDIA_CHANGED          = 13 | MAX_BIT
  "Not Found",                    //  RETURN_NOT_FOUND              = 14 | MAX_BIT
  "Access Denied",                //  RETURN_ACCESS_DENIED          = 15 | MAX_BIT
  "No Response",                  //  RETURN_NO_RESPONSE            = 16 | MAX_BIT
  "No mapping",                   //  RETURN_NO_MAPPING             = 17 | MAX_BIT
  "Time out",                     //  RETURN_TIMEOUT                = 18 | MAX_BIT
  "Not started",                  //  RETURN_NOT_STARTED            = 19 | MAX_BIT
  "Already started",              //  RETURN_ALREADY_STARTED        = 20 | MAX_BIT
  "Aborted",                      //  RETURN_ABORTED                = 21 | MAX_BIT
  "ICMP Error",                   //  RETURN_ICMP_ERROR             = 22 | MAX_BIT
  "TFTP Error",                   //  RETURN_TFTP_ERROR             = 23 | MAX_BIT
  "Protocol Error"                //  RETURN_PROTOCOL_ERROR         = 24 | MAX_BIT
};


/**
  Internal function that places the character into the Buffer.

  Internal function that places ASCII or Unicode character into the Buffer.

  @param  Buffer      Buffer to place the Unicode or ASCII string.
  @param  EndBuffer   The end of the input Buffer. No characters will be
                      placed after that. 
  @param  Length      Count of character to be placed into Buffer.
                      (Negative value indicates no buffer fill.)
  @param  Character   Character to be placed into Buffer.
  @param  Increment   Character increment in Buffer.

  @return Buffer      Buffer filled with the input Character.

**/
CHAR8 *
BasePrintLibFillBuffer (
  OUT CHAR8   *Buffer,
  IN  CHAR8   *EndBuffer,
  IN  INTN    Length,
  IN  UINTN   Character,
  IN  INTN    Increment
  )
{
  INTN  Index;
  
  for (Index = 0; Index < Length && Buffer < EndBuffer; Index++) {
    *Buffer = (CHAR8) Character;
    if (Increment != 1) {
      *(Buffer + 1) = (CHAR8)(Character >> 8);
    }
    Buffer += Increment;
  }

  return Buffer;
}

/**
  Internal function that convert a number to a string in Buffer.

  Print worker function that converts a decimal or hexadecimal number to an ASCII string in Buffer.

  @param  Buffer    Location to place the ASCII string of Value.
  @param  Value     Value to convert to a Decimal or Hexadecimal string in Buffer.
  @param  Radix     Radix of the value

  @return A pointer to the end of buffer filled with ASCII string.

**/
CHAR8 *
BasePrintLibValueToString (
  IN OUT CHAR8  *Buffer, 
  IN INT64      Value, 
  IN UINTN      Radix
  )
{
  UINT32  Remainder;

  //
  // Loop to convert one digit at a time in reverse order
  //
  *Buffer = 0;
  do {
    Value = (INT64)DivU64x32Remainder ((UINT64)Value, (UINT32)Radix, &Remainder);
    *(++Buffer) = mHexStr[Remainder];
  } while (Value != 0);

  //
  // Return pointer of the end of filled buffer.
  //
  return Buffer;
}

/**
  Internal function that converts a decimal value to a Null-terminated string.
  
  Converts the decimal number specified by Value to a Null-terminated  
  string specified by Buffer containing at most Width characters.
  If Width is 0 then a width of  MAXIMUM_VALUE_CHARACTERS is assumed.
  The total number of characters placed in Buffer is returned.
  If the conversion contains more than Width characters, then only the first
  Width characters are returned, and the total number of characters 
  required to perform the conversion is returned.
  Additional conversion parameters are specified in Flags.  
  The Flags bit LEFT_JUSTIFY is always ignored.
  All conversions are left justified in Buffer.
  If Width is 0, PREFIX_ZERO is ignored in Flags.
  If COMMA_TYPE is set in Flags, then PREFIX_ZERO is ignored in Flags, and commas
  are inserted every 3rd digit starting from the right.
  If Value is < 0, then the fist character in Buffer is a '-'.
  If PREFIX_ZERO is set in Flags and PREFIX_ZERO is not being ignored, 
  then Buffer is padded with '0' characters so the combination of the optional '-' 
  sign character, '0' characters, digit characters for Value, and the Null-terminator
  add up to Width characters.

  If Buffer is NULL, then ASSERT().
  If unsupported bits are set in Flags, then ASSERT().
  If Width >= MAXIMUM_VALUE_CHARACTERS, then ASSERT()

  @param  Buffer    Pointer to the output buffer for the produced Null-terminated
                    string.
  @param  Flags     The bitmask of flags that specify left justification, zero pad,
                    and commas.
  @param  Value     The 64-bit signed value to convert to a string.
  @param  Width     The maximum number of characters to place in Buffer, not including
                    the Null-terminator.
  @param  Increment Character increment in Buffer.
  
  @return Total number of characters required to perform the conversion.

**/
UINTN
BasePrintLibConvertValueToString (
  IN OUT CHAR8   *Buffer,
  IN UINTN       Flags,
  IN INT64       Value,
  IN UINTN       Width,
  IN UINTN       Increment
  )
{
  CHAR8  *OriginalBuffer;
  CHAR8  *EndBuffer;
  CHAR8  ValueBuffer[MAXIMUM_VALUE_CHARACTERS];
  CHAR8  *ValueBufferPtr;
  UINTN  Count;
  UINTN  Digits;
  UINTN  Index;
  UINTN  Radix;

  //
  // Make sure Buffer is not NULL and Width < MAXIMUM
  //
  ASSERT (Buffer != NULL);
  ASSERT (Width < MAXIMUM_VALUE_CHARACTERS);
  //
  // Make sure Flags can only contain supported bits.
  //
  ASSERT ((Flags & ~(LEFT_JUSTIFY | COMMA_TYPE | PREFIX_ZERO | RADIX_HEX)) == 0);

  //
  // If both COMMA_TYPE and HEX_RADIX are set, then ASSERT ()
  //
  ASSERT (((Flags & COMMA_TYPE) == 0) || ((Flags & RADIX_HEX) == 0));

  OriginalBuffer = Buffer;
  
  //
  // Width is 0 or COMMA_TYPE is set, PREFIX_ZERO is ignored.
  //
  if (Width == 0 || (Flags & COMMA_TYPE) != 0) {
    Flags &= (~PREFIX_ZERO);
  }
  //
  // If Width is 0 then a width of  MAXIMUM_VALUE_CHARACTERS is assumed.
  //
  if (Width == 0) {
    Width = MAXIMUM_VALUE_CHARACTERS - 1;
  }
  //
  // Set the tag for the end of the input Buffer.
  //
  EndBuffer = Buffer + Width * Increment;
  
  //
  // Convert decimal negative
  //
  if ((Value < 0) && ((Flags & RADIX_HEX) == 0)) {
    Value = -Value;
    Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, 1, '-', Increment);
    Width--;
  }
  
  //
  // Count the length of the value string.
  //
  Radix = ((Flags & RADIX_HEX) == 0)? 10 : 16;
  ValueBufferPtr = BasePrintLibValueToString (ValueBuffer, Value, Radix);
  Count = ValueBufferPtr - ValueBuffer;
  
  //
  // Append Zero
  //
  if ((Flags & PREFIX_ZERO) != 0) {
    Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, Width - Count, '0', Increment);
  }
  
  //
  // Print Comma type for every 3 characters
  //
  Digits = Count % 3;
  if (Digits != 0) {
    Digits = 3 - Digits;
  }
  for (Index = 0; Index < Count; Index++) {
    Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, 1, *ValueBufferPtr--, Increment);
    if ((Flags & COMMA_TYPE) != 0) {
      Digits++;
      if (Digits == 3) {
        Digits = 0;
        if ((Index + 1) < Count) {
          Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, 1, ',', Increment);
        }
      }
    }
  }
  
  //
  // Print Null-terminator
  //
  BasePrintLibFillBuffer (Buffer, EndBuffer + Increment, 1, 0, Increment);

  return ((Buffer - OriginalBuffer) / Increment);
}

/**
  Worker function that produces a Null-terminated string in an output buffer 
  based on a Null-terminated format string and a VA_LIST argument list.

  VSPrint function to process format and place the results in Buffer. Since a 
  VA_LIST is used this routine allows the nesting of Vararg routines. Thus 
  this is the main print working routine.

  @param  Buffer      Character buffer to print the results of the parsing
                      of Format into.
  @param  BufferSize  Maximum number of characters to put into buffer.
  @param  Flags       Initial flags value.
                      Can only have FORMAT_UNICODE and OUTPUT_UNICODE set.
  @param  Format      Null-terminated format string.
  @param  Marker      Vararg list consumed by processing Format.

  @return Number of characters printed not including the Null-terminator.

**/
UINTN
BasePrintLibVSPrint (
  OUT CHAR8        *Buffer,
  IN  UINTN        BufferSize,
  IN  UINTN        Flags,
  IN  CONST CHAR8  *Format,
  IN  VA_LIST      Marker
  )
{
  CHAR8           *OriginalBuffer;
  CHAR8           *EndBuffer;
  CHAR8           ValueBuffer[MAXIMUM_VALUE_CHARACTERS];
  UINTN           BytesPerOutputCharacter;
  UINTN           BytesPerFormatCharacter;
  UINTN           FormatMask;
  UINTN           FormatCharacter;
  UINTN           Width;
  UINTN           Precision;
  INT64           Value;
  CONST CHAR8     *ArgumentString;
  UINTN           Character;
  GUID            *TmpGuid;
  TIME            *TmpTime;
  UINTN           Count;
  UINTN           ArgumentMask;
  INTN            BytesPerArgumentCharacter;
  UINTN           ArgumentCharacter;
  BOOLEAN         Done;
  UINTN           Index;
  CHAR8           Prefix;
  BOOLEAN         ZeroPad;
  BOOLEAN         Comma;
  UINTN           Digits;
  UINTN           Radix;
  RETURN_STATUS   Status;

  if (BufferSize == 0) {
    return 0;
  }
  ASSERT (Buffer != NULL);

  if ((Flags & OUTPUT_UNICODE) != 0) {
    BytesPerOutputCharacter = 2;
  } else {
    BytesPerOutputCharacter = 1;
  }

  //
  // Reserve space for the Null terminator.
  //
  BufferSize--;
  OriginalBuffer = Buffer;
  //
  // Set the tag for the end of the input Buffer.
  //
  EndBuffer      = Buffer + BufferSize * BytesPerOutputCharacter;

  if ((Flags & FORMAT_UNICODE) != 0) {
    //
    // Make sure format string cannot contain more than PcdMaximumUnicodeStringLength
    // Unicode characters if PcdMaximumUnicodeStringLength is not zero. 
    //
    ASSERT (StrSize ((CHAR16 *) Format) != 0);
    BytesPerFormatCharacter = 2;
    FormatMask = 0xffff;
  } else {
    //
    // Make sure format string cannot contain more than PcdMaximumAsciiStringLength
    // Ascii characters if PcdMaximumAsciiStringLength is not zero. 
    //
    ASSERT (AsciiStrSize (Format) != 0);
    BytesPerFormatCharacter = 1;
    FormatMask = 0xff;
  }

  //
  // Get the first character from the format string
  //
  FormatCharacter = ((*Format & 0xff) | (*(Format + 1) << 8)) & FormatMask;

  //
  // Loop until the end of the format string is reached or the output buffer is full
  //
  while (FormatCharacter != 0 && Buffer < EndBuffer) {
    //
    // Clear all the flag bits except those that may have been passed in
    //
    Flags &= (OUTPUT_UNICODE | FORMAT_UNICODE);

    //
    // Set the default width to zero, and the default precision to 1
    //
    Width     = 0;
    Precision = 1;
    Prefix    = 0;
    Comma     = FALSE;
    ZeroPad   = FALSE;
    Count     = 0;
    Digits    = 0;

    switch (FormatCharacter) {
    case '%':
      //
      // Parse Flags and Width
      //
      for (Done = FALSE; !Done; ) {
        Format += BytesPerFormatCharacter;
        FormatCharacter = ((*Format & 0xff) | (*(Format + 1) << 8)) & FormatMask;
        switch (FormatCharacter) {
        case '.': 
          Flags |= PRECISION; 
          break;
        case '-': 
          Flags |= LEFT_JUSTIFY; 
          break;
        case '+': 
          Flags |= PREFIX_SIGN;  
          break;
        case ' ': 
          Flags |= PREFIX_BLANK; 
          break;
        case ',': 
          Flags |= COMMA_TYPE; 
          break;
        case 'L':
        case 'l': 
          Flags |= LONG_TYPE;    
          break;
        case '*':
          if ((Flags & PRECISION) == 0) {
            Flags |= PAD_TO_WIDTH;
            Width = VA_ARG (Marker, UINTN);
          } else {
            Precision = VA_ARG (Marker, UINTN);
          }
          break;
        case '0':
          if ((Flags & PRECISION) == 0) {
            Flags |= PREFIX_ZERO;
          }
        case '1':
        case '2':
        case '3':
        case '4':
        case '5':
        case '6':
        case '7':
        case '8':
        case '9':
          for (Count = 0; ((FormatCharacter >= '0') &&  (FormatCharacter <= '9')); ){
            Count = (Count * 10) + FormatCharacter - '0';
            Format += BytesPerFormatCharacter;
            FormatCharacter = ((*Format & 0xff) | (*(Format + 1) << 8)) & FormatMask;
          }
          Format -= BytesPerFormatCharacter;
          if ((Flags & PRECISION) == 0) {
            Flags |= PAD_TO_WIDTH;
            Width = Count;
          } else {
            Precision = Count;
          }
          break;
       
        case '\0':
          //
          // Make no output if Format string terminates unexpectedly when
          // looking up for flag, width, precision and type. 
          //
          Format   -= BytesPerFormatCharacter;
          Precision = 0;
          //
          // break skipped on purpose.
          //
        default:
          Done = TRUE;
          break;
        }
      } 

      //
      // Handle each argument type
      //
      switch (FormatCharacter) {
      case 'p':
        //
        // Flag space, +, 0, L & l are invalid for type p.
        //
        Flags &= ~(PREFIX_BLANK | PREFIX_SIGN | PREFIX_ZERO | LONG_TYPE);
        if (sizeof (VOID *) > 4) {
          Flags |= LONG_TYPE;
        }
      case 'X':
        Flags |= PREFIX_ZERO;
        //
        // break skipped on purpose
        //
      case 'x':
        Flags |= RADIX_HEX;
        //
        // break skipped on purpose
        //
      case 'd':
        if ((Flags & LONG_TYPE) == 0) {
          //
          // 'd','x', and 'X' that are not preceded by 'l' or 'L' are assumed to be type "int".
          // This assumption is made so the format string definition is compatible with the ANSI C
          // Specification for formatted strings.  It is recommended that the Base Types be used 
          // everywhere, but in this one case, compliance with ANSI C is more important, and 
          // provides an implementation that is compatible with that largest possible set of CPU 
          // architectures.  This is why the type "int" is used in this one case.
          //
          Value = (VA_ARG (Marker, int));
        } else {
          Value = VA_ARG (Marker, INT64);
        }
        if ((Flags & PREFIX_BLANK) != 0) {
          Prefix = ' ';
        }
        if ((Flags & PREFIX_SIGN) != 0) {
          Prefix = '+';
        }
        if ((Flags & COMMA_TYPE) != 0) {
          Comma = TRUE;
        }
        if ((Flags & RADIX_HEX) == 0) {
          Radix = 10;
          if (Comma) {
            Flags &= (~PREFIX_ZERO);
            Precision = 1;
          }
          if (Value < 0) {
            Flags |= PREFIX_SIGN;
            Prefix = '-';
            Value = -Value;
          }
        } else {
          Radix = 16;
          Comma = FALSE;
          if ((Flags & LONG_TYPE) == 0 && Value < 0) {
            //
            // 'd','x', and 'X' that are not preceded by 'l' or 'L' are assumed to be type "int".
            // This assumption is made so the format string definition is compatible with the ANSI C
            // Specification for formatted strings.  It is recommended that the Base Types be used 
            // everywhere, but in this one case, compliance with ANSI C is more important, and 
            // provides an implementation that is compatible with that largest possible set of CPU 
            // architectures.  This is why the type "unsigned int" is used in this one case.
            //
            Value = (unsigned int)Value;
          }
        }
        //
        // Convert Value to a reversed string
        //
        Count = BasePrintLibValueToString (ValueBuffer, Value, Radix) - ValueBuffer;
        if (Value == 0 && Precision == 0) {
          Count = 0;
        }
        ArgumentString = (CHAR8 *)ValueBuffer + Count;
        
        Digits = Count % 3;
        if (Digits != 0) {
          Digits = 3 - Digits;
        }
        if (Comma && Count != 0) {
          Count += ((Count - 1) / 3);
        }
        if (Prefix != 0) {
          Count++;
          Precision++;
        }
        Flags |= ARGUMENT_REVERSED;
        ZeroPad = TRUE;
        if ((Flags & PREFIX_ZERO) != 0) {
          if ((Flags & LEFT_JUSTIFY) == 0) {
            if ((Flags & PAD_TO_WIDTH) != 0) {
              if ((Flags & PRECISION) == 0) {
                Precision = Width;
              }
            }
          }
        }
        break;

      case 's':
      case 'S':
        Flags |= ARGUMENT_UNICODE;
        //
        // break skipped on purpose
        //
      case 'a':
        ArgumentString = (CHAR8 *)VA_ARG (Marker, CHAR8 *);
        if (ArgumentString == NULL) {
          Flags &= (~ARGUMENT_UNICODE);
          ArgumentString = "<null string>";
        }
        //
        // Set the default precision for string to be zero if not specified.
        //
        if ((Flags & PRECISION) == 0) {
          Precision = 0;
        }
        break;

      case 'c':
        Character = VA_ARG (Marker, UINTN) & 0xffff;
        ArgumentString = (CHAR8 *)&Character;
        Flags |= ARGUMENT_UNICODE;
        break;

      case 'g':
        TmpGuid = VA_ARG (Marker, GUID *);
        if (TmpGuid == NULL) {
          ArgumentString = "<null guid>";
        } else {
          BasePrintLibSPrint (
            ValueBuffer,
            MAXIMUM_VALUE_CHARACTERS, 
            0,
            "%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
            TmpGuid->Data1,
            TmpGuid->Data2,
            TmpGuid->Data3,
            TmpGuid->Data4[0],
            TmpGuid->Data4[1],
            TmpGuid->Data4[2],
            TmpGuid->Data4[3],
            TmpGuid->Data4[4],
            TmpGuid->Data4[5],
            TmpGuid->Data4[6],
            TmpGuid->Data4[7]
            );
          ArgumentString = ValueBuffer;
        }
        break;

      case 't':
        TmpTime = VA_ARG (Marker, TIME *); 
        if (TmpTime == NULL) {
          ArgumentString = "<null time>";
        } else {
          BasePrintLibSPrint (
            ValueBuffer,
            MAXIMUM_VALUE_CHARACTERS,
            0,
            "%02d/%02d/%04d  %02d:%02d",
            TmpTime->Month,
            TmpTime->Day,
            TmpTime->Year,
            TmpTime->Hour,
            TmpTime->Minute
            );
          ArgumentString = ValueBuffer;
        }
        break;

      case 'r':
        Status = VA_ARG (Marker, RETURN_STATUS);
        ArgumentString = ValueBuffer;
        if (RETURN_ERROR (Status)) {
          //
          // Clear error bit
          //
          Index = Status & ~MAX_BIT;
          if (Index > 0 && Index <= ERROR_STATUS_NUMBER) {
            ArgumentString = mStatusString [Index + WARNING_STATUS_NUMBER];
          }
        } else {
          Index = Status;
          if (Index <= WARNING_STATUS_NUMBER) {
            ArgumentString = mStatusString [Index];
          }
        }
        if (ArgumentString == ValueBuffer) {
          BasePrintLibSPrint ((CHAR8 *) ValueBuffer, MAXIMUM_VALUE_CHARACTERS, 0, "%08X", Status);
        }
        break;

      case '\n':
        ArgumentString = "\n\r";
        break;

      case '%':
      default:
        //
        // if the type is '%' or unknown, then print it to the screen
        //
        ArgumentString = (CHAR8 *)&FormatCharacter;
        Flags |= ARGUMENT_UNICODE;
        break;
      }
      break;
 
    case '\n':
      ArgumentString = "\n\r";
      break;

    default:
      ArgumentString = (CHAR8 *)&FormatCharacter;
      Flags |= ARGUMENT_UNICODE;
      break;
    }

    //
    // Retrieve the ArgumentString attriubutes
    //
    if ((Flags & ARGUMENT_UNICODE) != 0) {
      ArgumentMask = 0xffff;
      BytesPerArgumentCharacter = 2;
    } else {
      ArgumentMask = 0xff;
      BytesPerArgumentCharacter = 1;
    }
    if ((Flags & ARGUMENT_REVERSED) != 0) {
      BytesPerArgumentCharacter = -BytesPerArgumentCharacter;
    } else {
      //
      // Compute the number of characters in ArgumentString and store it in Count
      // ArgumentString is either null-terminated, or it contains Precision characters
      //
      for (Count = 0; Count < Precision || ((Flags & PRECISION) == 0); Count++) {
        ArgumentCharacter = ((ArgumentString[Count * BytesPerArgumentCharacter] & 0xff) | ((ArgumentString[Count * BytesPerArgumentCharacter + 1]) << 8)) & ArgumentMask;
        if (ArgumentCharacter == 0) {
          break;
        }
      }
    }

    if (Precision < Count) {
      Precision = Count;
    }

    //
    // Pad before the string
    //
    if ((Flags & (PAD_TO_WIDTH | LEFT_JUSTIFY)) == (PAD_TO_WIDTH)) {
      Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, Width - Precision, ' ', BytesPerOutputCharacter);
    }

    if (ZeroPad) {
      if (Prefix != 0) {
        Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, 1, Prefix, BytesPerOutputCharacter);
      }
      Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, Precision - Count, '0', BytesPerOutputCharacter);
    } else {
      Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, Precision - Count, ' ', BytesPerOutputCharacter);
      if (Prefix != 0) {
        Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, 1, Prefix, BytesPerOutputCharacter);
      }
    }

    //
    // Output the Prefix character if it is present
    //
    Index = 0;
    if (Prefix != 0) {
      Index++;
    }

    //
    // Copy the string into the output buffer performing the required type conversions
    //
    while (Index < Count) {
      ArgumentCharacter = ((*ArgumentString & 0xff) | (*(ArgumentString + 1) << 8)) & ArgumentMask;

      Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, 1, ArgumentCharacter, BytesPerOutputCharacter);
      ArgumentString    += BytesPerArgumentCharacter;
      Index++;
      if (Comma) {
        Digits++;
        if (Digits == 3) {
          Digits = 0;
          Index++;
          if (Index < Count) {
            Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, 1, ',', BytesPerOutputCharacter);
          }
        }
      }
    }

    //
    // Pad after the string
    //
    if ((Flags & (PAD_TO_WIDTH | LEFT_JUSTIFY)) == (PAD_TO_WIDTH | LEFT_JUSTIFY)) {
      Buffer = BasePrintLibFillBuffer (Buffer, EndBuffer, Width - Precision, ' ', BytesPerOutputCharacter);
    }

    //
    // Get the next character from the format string
    //
    Format += BytesPerFormatCharacter;

    //
    // Get the next character from the format string
    //
    FormatCharacter = ((*Format & 0xff) | (*(Format + 1) << 8)) & FormatMask;
  }

  //
  // Null terminate the Unicode or ASCII string
  //
  BasePrintLibFillBuffer (Buffer, EndBuffer + BytesPerOutputCharacter, 1, 0, BytesPerOutputCharacter);
  //
  // Make sure output buffer cannot contain more than PcdMaximumUnicodeStringLength
  // Unicode characters if PcdMaximumUnicodeStringLength is not zero. 
  //
  ASSERT ((((Flags & OUTPUT_UNICODE) == 0)) || (StrSize ((CHAR16 *) OriginalBuffer) != 0));
  //
  // Make sure output buffer cannot contain more than PcdMaximumAsciiStringLength
  // ASCII characters if PcdMaximumAsciiStringLength is not zero. 
  //
  ASSERT ((((Flags & OUTPUT_UNICODE) != 0)) || (AsciiStrSize (OriginalBuffer) != 0));

  return ((Buffer - OriginalBuffer) / BytesPerOutputCharacter);
}

/**
  Worker function that produces a Null-terminated string in an output buffer 
  based on a Null-terminated format string and variable argument list.

  VSPrint function to process format and place the results in Buffer. Since a 
  VA_LIST is used this routine allows the nesting of Vararg routines. Thus 
  this is the main print working routine

  @param  StartOfBuffer Character buffer to print the results of the parsing
                        of Format into.
  @param  BufferSize    Maximum number of characters to put into buffer.
                        Zero means no limit.
  @param  Flags         Initial flags value.
                        Can only have FORMAT_UNICODE and OUTPUT_UNICODE set
  @param  FormatString  Null-terminated format string.
  @param  ...           The variable argument list.

  @return Number of characters printed.

**/
UINTN
BasePrintLibSPrint (
  OUT CHAR8        *StartOfBuffer,
  IN  UINTN        BufferSize,
  IN  UINTN        Flags,
  IN  CONST CHAR8  *FormatString,
  ...
  )
{
  VA_LIST  Marker;

  VA_START (Marker, FormatString);
  return BasePrintLibVSPrint (StartOfBuffer, BufferSize, Flags, FormatString, Marker);
}