Fix X64 native function call prolog. Prepare space for at least 4 arguments,

even if the native function's arguments are less than 4.
 
From MSDN x64 Software Conventions, Overview of x64 Calling Conventions:
“The caller is responsible for allocating space for parameters to the
callee, and must always allocate sufficient space for the 4 register
parameters, even if the callee doesn’t have that many parameters.
This aids in the simplicity of supporting C unprototyped functions,
and vararg C/C++ functions.”
 
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Samer El-Haj-Mahmoud elhaj@hp.com 
Reviewed by: Jiewen Yao <Jiewen.Yao@intel.com>
Reviewed by: Feng Tian <Feng.Tian@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16152 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 56 insertions, 1 deletions

diff --git a/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.S b/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.S
index 859cbce24c..b01486a871 100644
--- a/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.S
+++ b/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.S
@@ -3,7 +3,7 @@
 #    This code provides low level routines that support the Virtual Machine

 #   for option ROMs.

 #  

-#  Copyright (c) 2007 - 2011, Intel Corporation. All rights reserved.<BR>

+#  Copyright (c) 2007 - 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

@@ -46,7 +46,34 @@ ASM_PFX(EbcLLCALLEXNative):
 

       # Set stack pointer to new value

       sub    %rdx, %r8  

+      

+      #

+      # Fix X64 native function call prolog. Prepare space for at least 4 arguments,

+      # even if the native function's arguments are less than 4.

+      #

+      # From MSDN x64 Software Conventions, Overview of x64 Calling Conventions:

+      #   "The caller is responsible for allocating space for parameters to the

+      #   callee, and must always allocate sufficient space for the 4 register

+      #   parameters, even if the callee doesn't have that many parameters.

+      #   This aids in the simplicity of supporting C unprototyped functions,

+      #   and vararg C/C++ functions."

+      #

+      cmp    $0x20, %r8

+      jae    skip_expansion

+      mov    $0x20, %r8

+skip_expansion:

+      

       sub    %r8,  %rsp 

+      

+      #

+      # Fix X64 native function call 16-byte alignment.

+      #

+      # From MSDN x64 Software Conventions, Stack Usage:

+      #   "The stack will always be maintained 16-byte aligned, except within 

+      #   the prolog (for example, after the return address is pushed)."

+      #

+      and    $0xFFFFFFFFFFFFFFF0, %rsp

+      

       mov    %rsp, %rcx

       sub    $0x20, %rsp 

       call   ASM_PFX(CopyMem)

diff --git a/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.asm b/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.asm
index a79fdcabff..1fbd165be7 100644
--- a/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.asm
+++ b/MdeModulePkg/Universal/EbcDxe/X64/EbcLowLevel.asm
@@ -4,6 +4,7 @@
 ;    for option ROMs.

 ;  

 ;  Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>

+;  Copyright (c) 2014 Hewlett-Packard Development Company, L.P.<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

@@ -50,7 +51,34 @@ EbcLLCALLEXNative        PROC    PUBLIC
 

       ; Set stack pointer to new value

       sub    r8,  rdx

+

+      ;

+      ; Fix X64 native function call prolog. Prepare space for at least 4 arguments,

+      ; even if the native function's arguments are less than 4.

+      ;

+      ; From MSDN x64 Software Conventions, Overview of x64 Calling Conventions:

+      ;   "The caller is responsible for allocating space for parameters to the

+      ;   callee, and must always allocate sufficient space for the 4 register

+      ;   parameters, even if the callee doesn't have that many parameters.

+      ;   This aids in the simplicity of supporting C unprototyped functions,

+      ;   and vararg C/C++ functions."

+      ;

+      cmp    r8, 20h

+      jae    skip_expansion

+      mov    r8, 20h

+skip_expansion:

+      

       sub    rsp, r8

+

+      ;

+      ; Fix X64 native function call 16-byte alignment.

+      ;

+      ; From MSDN x64 Software Conventions, Stack Usage:

+      ;   "The stack will always be maintained 16-byte aligned, except within 

+      ;   the prolog (for example, after the return address is pushed)."

+      ;

+      and    rsp, NOT 0fh

+

       mov    rcx, rsp

       sub    rsp, 20h

       call   CopyMem