UefiCpuPkg/CpuMpPei: Load GDT table on BSP

[mirror_edk2.git] / UefiCpuPkg / CpuMpPei / Ia32 / MpFuncs.asm

diff --git a/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm
new file mode 100644 (file)
index 0000000..ca9c15a
--- /dev/null
+++ b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.asm
@@ -0,0 +1,55 @@
+;------------------------------------------------------------------------------ ;
+; Copyright (c) 2015, Intel Corporation. All rights reserved.<BR>
+; 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.
+;
+; Module Name:
+;
+;   MpFuncs32.asm
+;
+; Abstract:
+;
+;   This is the assembly code for MP support
+;
+;-------------------------------------------------------------------------------
+
+.686p
+.model  flat
+
+include  MpEqu.inc
+.code
+
+
+AsmInitializeGdt   PROC  near C  PUBLIC
+  push         ebp
+  mov          ebp, esp
+  pushad
+  mov          edi, [ebp + 8]      ; Load GDT register
+
+  mov          ax,cs               ; Get the selector data from our code image
+  mov          es,ax
+  lgdt         FWORD PTR es:[edi]  ; and update the GDTR
+
+  push         PROTECT_MODE_CS
+  lea          eax, SetCodeSelectorFarJump
+  push         eax
+  retf
+SetCodeSelectorFarJump:
+  mov          ax, PROTECT_MODE_DS ; Update the Base for the new selectors, too
+  mov          ds, ax
+  mov          es, ax
+  mov          fs, ax
+  mov          gs, ax
+  mov          ss, ax
+
+  popad
+  pop          ebp
+  ret
+AsmInitializeGdt  ENDP
+
+END