Port to gnu style.

[mirror_edk2.git] / EdkModulePkg / Universal / Ebc / Dxe / x64 / EbcLowLevel.S

diff --git a/EdkModulePkg/Universal/Ebc/Dxe/x64/EbcLowLevel.S b/EdkModulePkg/Universal/Ebc/Dxe/x64/EbcLowLevel.S
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+#****************************************************************************
+#*                                                                         
+#*  Copyright (c) 2006, Intel Corporation                                                         
+#*  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.             
+#*                                                                          
+#****************************************************************************
+#****************************************************************************
+#                                   REV 1.0
+#****************************************************************************
+#
+# Rev  Date      Description
+# ---  --------  ------------------------------------------------------------
+# 1.0  05/09/12  Initial creation of file.
+#
+#****************************************************************************
+
+#* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+# This code provides low level routines that support the Virtual Machine
+# for option ROMs. 
+#* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+
+#---------------------------------------------------------------------------
+# Equate files needed.
+#---------------------------------------------------------------------------
+
+#---------------------------------------------------------------------------
+##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)
+.global _EbcLLCALLEXNative;
+_EbcLLCALLEXNative:
+      push   %rbp
+      push   %rbx
+      mov    %rsp, %rbp
+      # Function prolog
+
+      # Copy FuncAddr to a preserved register.
+      mov    %rcx, %rbx
+
+      # Set stack pointer to new value
+      mov    %rdx, %rsp
+
+      # Considering the worst case, load 4 potiential arguments
+      # into registers.
+      mov    (%rsp), %rcx
+      mov    8(%rsp), %rdx
+      mov    10(%rsp), %r8
+      mov    18(%rsp), %r9
+
+      # Now call the external routine
+      call  *%rbx
+
+      # Function epilog
+      mov      %rbp, %rsp
+      pop      %rbx
+      pop      %rbp
+      ret
+
+
+# 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.
+#
+.global _EbcLLGetEbcEntryPoint;
+_EbcLLGetEbcEntryPoint:
+    ret
+
+#/*++
+#
+#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()            
+.global _EbcLLGetStackPointer;
+_EbcLLGetStackPointer:
+    mov    %rsp, %rax
+    # Stack adjusted by this much when we were called,
+    # For this function, it's 4.
+    add   $4, %rax
+    ret
+
+.global _EbcLLGetReturnValue;
+_EbcLLGetReturnValue:
+# 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.
+#
+    ret