MdePkg/Library/BaseLib/X64/XSetBv.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   XSetBv.nasm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   AsmXSetBv function
  13 ;
  14 ; Notes:
  15 ;
  16 ;------------------------------------------------------------------------------
  17
  18     DEFAULT REL
  19     SECTION .text
  20
  21 ;------------------------------------------------------------------------------
  22 ; UINT64
  23 ; EFIAPI
  24 ; AsmXSetBv (
  25 ;   IN UINT32  Index,
  26 ;   IN UINT64  Value
  27 ;   );
  28 ;------------------------------------------------------------------------------
  29 global ASM_PFX(AsmXSetBv)
  30 ASM_PFX(AsmXSetBv):
  31     mov     rax, rdx                    ; meanwhile, rax <- return value
  32     shr     rdx, 0x20                    ; edx:eax contains the value to write
  33     xsetbv
  34     ret