UefiCpuPkg/CpuMpPei: Load GDT table on BSP

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

diff --git a/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm
new file mode 100644 (file)
index 0000000..180b637
--- /dev/null
+++ b/UefiCpuPkg/CpuMpPei/Ia32/MpFuncs.nasm
@@ -0,0 +1,49 @@
+;------------------------------------------------------------------------------ ;
+; 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:
+;
+;   MpFuncs.nasm
+;
+; Abstract:
+;
+;   This is the assembly code for MP support
+;
+;-------------------------------------------------------------------------------
+
+%include "MpEqu.inc"
+
+SECTION .text
+
+
+global ASM_PFX(AsmInitializeGdt)
+ASM_PFX(AsmInitializeGdt):
+  push         ebp
+  mov          ebp, esp
+  pushad
+  mov          edi, [ebp + 8]      ; Load GDT register
+
+  lgdt         [edi]      ; and update the GDTR
+
+  push         PROTECT_MODE_CS
+  mov          eax, ASM_PFX(SetCodeSelectorFarJump)
+  push         eax
+  retf
+ASM_PFX(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