audk/MdeModulePkg/Universal/SetupBrowserDxe/R8Lib.c

244 lines
6.0 KiB
C

/**@file
Copyright (c) 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
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 "Setup.h"
CHAR16
NibbleToHexChar (
IN UINT8 Nibble
)
/*++
Routine Description:
Converts the low nibble of a byte to hex unicode character.
Arguments:
Nibble - lower nibble of a byte.
Returns:
Hex unicode character.
--*/
{
Nibble &= 0x0F;
if (Nibble <= 0x9) {
return (CHAR16)(Nibble + L'0');
}
return (CHAR16)(Nibble - 0xA + L'A');
}
/**
Converts binary buffer to Unicode string.
At a minimum, any blob of data could be represented as a hex string.
@param Str Pointer to the string.
@param HexStringBufferLength Length in bytes of buffer to hold the hex string.
Includes tailing '\0' character. If routine return
with EFI_SUCCESS, containing length of hex string
buffer. If routine return with
EFI_BUFFER_TOO_SMALL, containg length of hex
string buffer desired.
@param Buf Buffer to be converted from.
@param Len Length in bytes of the buffer to be converted.
@retval EFI_SUCCESS Routine success.
@retval EFI_BUFFER_TOO_SMALL The hex string buffer is too small.
**/
EFI_STATUS
R8_BufToHexString (
IN OUT CHAR16 *Str,
IN OUT UINTN *HexStringBufferLength,
IN UINT8 *Buf,
IN UINTN Len
)
{
//
// Porting Guide:
// This library interface is simply obsolete.
// Include the source code to user code.
//
UINTN Idx;
UINT8 Byte;
UINTN StrLen;
//
// Make sure string is either passed or allocate enough.
// It takes 2 Unicode characters (4 bytes) to represent 1 byte of the binary buffer.
// Plus the Unicode termination character.
//
StrLen = Len * 2;
if (StrLen > ((*HexStringBufferLength) - 1)) {
*HexStringBufferLength = StrLen + 1;
return EFI_BUFFER_TOO_SMALL;
}
*HexStringBufferLength = StrLen + 1;
//
// Ends the string.
//
Str[StrLen] = L'\0';
for (Idx = 0; Idx < Len; Idx++) {
Byte = Buf[Idx];
Str[StrLen - 1 - Idx * 2] = NibbleToHexChar (Byte);
Str[StrLen - 2 - Idx * 2] = NibbleToHexChar ((UINT8)(Byte >> 4));
}
return EFI_SUCCESS;
}
/**
Converts Unicode string to binary buffer.
The conversion may be partial.
The first character in the string that is not hex digit stops the conversion.
At a minimum, any blob of data could be represented as a hex string.
@param Buf Pointer to buffer that receives the data.
@param Len Length in bytes of the buffer to hold converted
data. If routine return with EFI_SUCCESS,
containing length of converted data. If routine
return with EFI_BUFFER_TOO_SMALL, containg length
of buffer desired.
@param Str String to be converted from.
@param ConvertedStrLen Length of the Hex String consumed.
@retval EFI_SUCCESS Routine Success.
@retval EFI_BUFFER_TOO_SMALL The buffer is too small to hold converted data.
**/
EFI_STATUS
R8_HexStringToBuf (
IN OUT UINT8 *Buf,
IN OUT UINTN *Len,
IN CHAR16 *Str,
OUT UINTN *ConvertedStrLen OPTIONAL
)
{
//
// Porting Guide:
// This library interface is simply obsolete.
// Include the source code to user code.
//
UINTN HexCnt;
UINTN Idx;
UINTN BufferLength;
UINT8 Digit;
UINT8 Byte;
//
// Find out how many hex characters the string has.
//
for (Idx = 0, HexCnt = 0; R8_IsHexDigit (&Digit, Str[Idx]); Idx++, HexCnt++);
if (HexCnt == 0) {
*Len = 0;
return EFI_SUCCESS;
}
//
// Two Unicode characters make up 1 buffer byte. Round up.
//
BufferLength = (HexCnt + 1) / 2;
//
// Test if buffer is passed enough.
//
if (BufferLength > (*Len)) {
*Len = BufferLength;
return EFI_BUFFER_TOO_SMALL;
}
*Len = BufferLength;
for (Idx = 0; Idx < HexCnt; Idx++) {
R8_IsHexDigit (&Digit, Str[HexCnt - 1 - Idx]);
//
// For odd charaters, write the lower nibble for each buffer byte,
// and for even characters, the upper nibble.
//
if ((Idx & 1) == 0) {
Byte = Digit;
} else {
Byte = Buf[Idx / 2];
Byte &= 0x0F;
Byte = (UINT8) (Byte | Digit << 4);
}
Buf[Idx / 2] = Byte;
}
if (ConvertedStrLen != NULL) {
*ConvertedStrLen = HexCnt;
}
return EFI_SUCCESS;
}
/**
Determines if a Unicode character is a hexadecimal digit.
The test is case insensitive.
@param Digit Pointer to byte that receives the value of the hex
character.
@param Char Unicode character to test.
@retval TRUE If the character is a hexadecimal digit.
@retval FALSE Otherwise.
**/
BOOLEAN
R8_IsHexDigit (
OUT UINT8 *Digit,
IN CHAR16 Char
)
{
//
// Porting Guide:
// This library interface is simply obsolete.
// Include the source code to user code.
//
if ((Char >= L'0') && (Char <= L'9')) {
*Digit = (UINT8) (Char - L'0');
return TRUE;
}
if ((Char >= L'A') && (Char <= L'F')) {
*Digit = (UINT8) (Char - L'A' + 0x0A);
return TRUE;
}
if ((Char >= L'a') && (Char <= L'f')) {
*Digit = (UINT8) (Char - L'a' + 0x0A);
return TRUE;
}
return FALSE;
}