MdePkg/Library/BaseLib/Ia32/ReadCs.c

   1 /** @file
   2   AsmReadCs function
   3
   4   Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9
  10
  11
  12 /**
  13   Reads the current value of Code Segment Register (CS).
  14
  15   Reads and returns the current value of CS. This function is only available on
  16   IA-32 and x64.
  17
  18   @return The current value of CS.
  19
  20 **/
  21 UINT16
  22 EFIAPI
  23 AsmReadCs (
  24   VOID
  25   )
  26 {
  27   __asm {
  28     xor     eax, eax
  29     mov     ax, cs
  30   }
  31 }
  32