[MdePkg/BaseLib v1 1/1] MdePkg BaseLib: Add new API CalculateCrc16()

[Ming Huang <ming.huang@linaro.org>]

CalculateCrc16() bases on the initialized mCrcTable. When CalculateCrc16()
is used, mCrcTable16 will take 512Bytes size in the image. When
CalculateCrc16() is not used, mCrcTable16 will not be built in the image,
and no size impact.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ming Huang <ming.huang@linaro.org>
---
 MdePkg/Include/Library/BaseLib.h  | 20 ++++++
 MdePkg/Library/BaseLib/CheckSum.c | 73 ++++++++++++++++++++
 2 files changed, 93 insertions(+)

diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
index 1eb842384ee2..956b971e5c69 100644
--- a/MdePkg/Include/Library/BaseLib.h
+++ b/MdePkg/Include/Library/BaseLib.h
@@ -4855,6 +4855,26 @@ CalculateCrc32(
   IN  UINTN                        Length
   );
 
+/**
+  Computes and returns a 16-bit CRC for a data buffer.
+  CRC16 value bases on CCITT.
+
+  If Buffer is NULL, then ASSERT().
+  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
+
+  @param[in]  Buffer       A pointer to the buffer on which the 16-bit CRC is to be computed.
+  @param[in]  Length      The number of bytes in the buffer Data.
+
+  @retval Crc16            The 16-bit CRC was computed for the data buffer.
+
+**/
+UINT16
+EFIAPI
+CalculateCrc16(
+  IN  VOID                         *Buffer,
+  IN  UINTN                        Length
+  );
+
 //
 // Base Library CPU Functions
 //
diff --git a/MdePkg/Library/BaseLib/CheckSum.c b/MdePkg/Library/BaseLib/CheckSum.c
index 03d49afc5e6c..4e27aebe44bc 100644
--- a/MdePkg/Library/BaseLib/CheckSum.c
+++ b/MdePkg/Library/BaseLib/CheckSum.c
@@ -630,3 +630,76 @@ CalculateCrc32(
 
   return Crc ^ 0xffffffff;
 }
+
+GLOBAL_REMOVE_IF_UNREFERENCED CONST UINT16  mCrcTable16[256] = {
+  0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
+  0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
+  0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
+  0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
+  0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
+  0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
+  0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
+  0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
+  0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
+  0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
+  0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
+  0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
+  0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
+  0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
+  0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
+  0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
+  0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
+  0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
+  0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
+  0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
+  0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
+  0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
+  0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
+  0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
+  0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
+  0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
+  0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
+  0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
+  0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
+  0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
+  0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
+  0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
+};
+
+/**
+  Computes and returns a 16-bit CRC for a data buffer.
+  CRC16 value bases on CCITT.
+
+  If Buffer is NULL, then ASSERT().
+  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
+
+  @param[in]  Buffer       A pointer to the buffer on which the 16-bit CRC is to be computed.
+  @param[in]  Length      The number of bytes in the buffer Data.
+
+  @retval Crc16            The 16-bit CRC was computed for the data buffer.
+
+**/
+UINT16
+EFIAPI
+CalculateCrc16(
+  IN  VOID                         *Buffer,
+  IN  UINTN                        Length
+  )
+{
+  UINT16  Crc;
+  UINT8   *Ptr;
+
+  ASSERT (Buffer != NULL);
+  ASSERT (Length <= (MAX_ADDRESS - ((UINTN) Buffer) + 1));
+
+  Crc = 0;
+  Ptr = (UINT8 *)Buffer;
+  while (Length) {
+    Crc = mCrcTable16[((UINT8)((Crc >> 8) & 0xff)) ^ *(Ptr++)] ^
+            ((UINT16)(Crc << 8));
+    Length--;
+  }
+
+  return Crc;
+}
+
-- 
2.9.5