UefiCpuPkg/CpuDxe/Ia32/CpuAsm.S

   1 #------------------------------------------------------------------------------
   2 #*
   3 #*   Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.<BR>
   4 #*   This program and the accompanying materials
   5 #*   are licensed and made available under the terms and conditions of the BSD License
   6 #*   which accompanies this distribution.  The full text of the license may be found at
   7 #*   http://opensource.org/licenses/bsd-license.php
   8 #*
   9 #*   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 #*   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 #*
  12 #*    CpuAsm.S
  13 #*
  14 #*   Abstract:
  15 #*
  16 #------------------------------------------------------------------------------
  17
  18
  19 #.MMX
  20 #.XMM
  21
  22 #------------------------------------------------------------------------------
  23 # VOID
  24 # SetCodeSelector (
  25 #   UINT16 Selector
  26 #   );
  27 #------------------------------------------------------------------------------
  28 ASM_GLOBAL ASM_PFX(SetCodeSelector)
  29 ASM_PFX(SetCodeSelector):
  30     movl    4(%esp), %ecx
  31     subl    $0x10, %esp
  32     leal    setCodeSelectorLongJump, %eax
  33     movl    %eax, (%esp)
  34     movw    %cx, 4(%esp)
  35     .byte   0xFF, 0x2C, 0x24   # jmp *(%esp)  note:(FWORD jmp)
  36 setCodeSelectorLongJump:
  37     addl    $0x10, %esp
  38     ret
  39
  40 #------------------------------------------------------------------------------
  41 # VOID
  42 # SetDataSelectors (
  43 #   UINT16 Selector
  44 #   );
  45 #------------------------------------------------------------------------------
  46 ASM_GLOBAL ASM_PFX(SetDataSelectors)
  47 ASM_PFX(SetDataSelectors):
  48     movl    4(%esp), %ecx
  49     movw    %cx, %ss
  50     movw    %cx, %ds
  51     movw    %cx, %es
  52     movw    %cx, %fs
  53     movw    %cx, %gs
  54     ret
  55
  56 #END
  57