1 files changed, 68 insertions, 0 deletions
diff --git a/Core/UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm b/Core/UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm
new file mode 100644
index 0000000000..c47cdcef54
--- /dev/null
+++ b/Core/UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm
@@ -0,0 +1,68 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006 - 2014, 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.
+;
+;------------------------------------------------------------------------------
+
+extern ASM_PFX(mTopOfApCommonStack)
+extern ASM_PFX(ApEntryPointInC)
+
+SECTION .data
+
+;
+; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
+;
+ApStackLock:
+    dd      0
+
+SECTION .text
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmApEntryPoint (
+;   VOID
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmApEntryPoint)
+ASM_PFX(AsmApEntryPoint):
+    cli
+AsmApEntryPointAcquireLock:
+lock bts    dword [ApStackLock], 0
+    pause
+    jc      AsmApEntryPointAcquireLock
+
+    mov     esp, [ASM_PFX(mTopOfApCommonStack)]
+    call    ASM_PFX(ApEntryPointInC)
+
+    cli
+
+lock btc    dword [ApStackLock], 0
+
+    mov     eax, 0x100
+AsmApEntryPointShareLock:
+    pause
+    dec     eax
+    jnz     AsmApEntryPointShareLock
+
+    jmp     ASM_PFX(AsmApEntryPoint)
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmApDoneWithCommonStack (
+;   VOID
+;   );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmApDoneWithCommonStack)
+ASM_PFX(AsmApDoneWithCommonStack):
+lock btc    dword [ApStackLock], 0
+    ret
+