Use "X64" for directory name to follow directory name convention.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@5258 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.asm

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+;/** @file
+;  
+;    This code provides low level routines that support the Virtual Machine.
+;    for option ROMs.
+;  
+;  Copyright (c) 2006 - 2008, Intel Corporation. <BR>
+;  All rights reserved. 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.
+;  
+;**/
+
+  page    ,132
+  title   VM ASSEMBLY LANGUAGE ROUTINES
+
+;---------------------------------------------------------------------------
+; Equate files needed.
+;---------------------------------------------------------------------------
+
+text SEGMENT
+
+;---------------------------------------------------------------------------
+;;GenericPostSegment      SEGMENT USE16
+;---------------------------------------------------------------------------
+
+;****************************************************************************
+; EbcLLCALLEX
+;
+; This function is called to execute an EBC CALLEX instruction.
+; This instruction requires that we thunk out to external native
+; code. For x64, we switch stacks, copy the arguments to the stack
+; and jump to the specified function.
+; On return, we restore the stack pointer to its original location.
+;
+; Destroys no working registers.
+;****************************************************************************
+; VOID EbcLLCALLEXNative(UINTN FuncAddr, UINTN NewStackPointer, VOID *FramePtr)
+
+CopyMem  PROTO  Destination:PTR DWORD, Source:PTR DWORD, Count:DWORD
+
+
+EbcLLCALLEXNative        PROC    PUBLIC
+      push   rbp
+      push   rbx
+      mov    rbp, rsp
+      ; Function prolog
+
+      ; Copy FuncAddr to a preserved register.
+      mov    rbx, rcx
+
+      ; Set stack pointer to new value
+      sub    r8,  rdx
+      sub    rsp, r8
+      mov    rcx, rsp
+      sub    rsp, 20h
+      call   CopyMem
+      add    rsp, 20h
+
+      ; Considering the worst case, load 4 potiential arguments
+      ; into registers.
+      mov    rcx, qword ptr [rsp]
+      mov    rdx, qword ptr [rsp+8h]
+      mov    r8,  qword ptr [rsp+10h]
+      mov    r9,  qword ptr [rsp+18h]
+
+      ; Now call the external routine
+      call  rbx
+
+      ; Function epilog
+      mov      rsp, rbp
+      pop      rbx
+      pop      rbp
+      ret
+EbcLLCALLEXNative    ENDP
+
+
+; UINTN EbcLLGetEbcEntryPoint(VOID);
+; Routine Description:
+;   The VM thunk code stuffs an EBC entry point into a processor
+;   register. Since we can't use inline assembly to get it from
+;   the interpreter C code, stuff it into the return value
+;   register and return.
+;
+; Arguments:
+;     None.
+;
+; Returns:
+;     The contents of the register in which the entry point is passed.
+;
+EbcLLGetEbcEntryPoint        PROC    PUBLIC
+    ret
+EbcLLGetEbcEntryPoint    ENDP
+
+;/*++
+;
+;Routine Description:
+;
+;  Return the caller's value of the stack pointer.
+;
+;Arguments:
+;
+;  None.
+;
+;Returns:
+;
+;  The current value of the stack pointer for the caller. We
+;  adjust it by 4 here because when they called us, the return address
+;  is put on the stack, thereby lowering it by 4 bytes.
+;
+;--*/
+
+; UINTN EbcLLGetStackPointer()
+EbcLLGetStackPointer        PROC    PUBLIC
+    mov    rax, rsp      ; get current stack pointer
+    ; Stack adjusted by this much when we were called,
+    ; For this function, it's 4.
+    add   rax, 4
+    ret
+EbcLLGetStackPointer    ENDP
+
+; UINT64 EbcLLGetReturnValue(VOID);
+; Routine Description:
+;   When EBC calls native, on return the VM has to stuff the return
+;   value into a VM register. It's assumed here that the value is still
+;    in the register, so simply return and the caller should get the
+;   return result properly.
+;
+; Arguments:
+;     None.
+;
+; Returns:
+;     The unmodified value returned by the native code.
+;
+EbcLLGetReturnValue   PROC    PUBLIC
+    ret
+EbcLLGetReturnValue    ENDP
+
+text  ENDS
+END
+