MdeModulePkg EbcDxe: Convert Ia32/EbcLowLevel.asm to NASM
The BaseTools/Scripts/ConvertMasmToNasm.py script was used to convert
Ia32/EbcLowLevel.asm to Ia32/EbcLowLevel.nasm
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
diff --git a/MdeModulePkg/Universal/EbcDxe/EbcDxe.inf b/MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
index 0dfe005..44558aa 100644
--- a/MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
+++ b/MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
@@ -39,6 +39,7 @@
[Sources.Ia32]
Ia32/EbcSupport.c
+ Ia32/EbcLowLevel.nasm
Ia32/EbcLowLevel.S
Ia32/EbcLowLevel.asm
diff --git a/MdeModulePkg/Universal/EbcDxe/Ia32/EbcLowLevel.nasm b/MdeModulePkg/Universal/EbcDxe/Ia32/EbcLowLevel.nasm
new file mode 100644
index 0000000..29a101d
--- /dev/null
+++ b/MdeModulePkg/Universal/EbcDxe/Ia32/EbcLowLevel.nasm
@@ -0,0 +1,197 @@
+;/** @file
+;
+; This code provides low level routines that support the Virtual Machine
+; for option ROMs.
+;
+; Copyright (c) 2006 - 2011, 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.
+;
+;**/
+
+;---------------------------------------------------------------------------
+; Equate files needed.
+;---------------------------------------------------------------------------
+
+;---------------------------------------------------------------------------
+; Assembler options
+;---------------------------------------------------------------------------
+
+SECTION .text
+extern ASM_PFX(CopyMem)
+extern ASM_PFX(EbcInterpret)
+extern ASM_PFX(ExecuteEbcImageEntryPoint)
+
+;****************************************************************************
+; EbcLLCALLEXNative
+;
+; This function is called to execute an EBC CALLEX instruction
+; to native code.
+; This instruction requires that we thunk out to external native
+; code. For IA32, we simply switch stacks and jump to the
+; specified function. On return, we restore the stack pointer
+; to its original location.
+;
+; Destroys no working registers.
+;****************************************************************************
+; INT64 EbcLLCALLEXNative(UINTN FuncAddr, UINTN NewStackPointer, VOID *FramePtr)
+global ASM_PFX(EbcLLCALLEXNative)
+ASM_PFX(EbcLLCALLEXNative):
+ push ebp
+ push ebx
+ mov ebp, esp ; standard function prolog
+
+ ; Get function address in a register
+ ; mov ecx, FuncAddr => mov ecx, dword ptr [FuncAddr]
+ mov ecx, dword [esp + 0xC]
+
+ ; Set stack pointer to new value
+ ; mov eax, NewStackPointer => mov eax, dword ptr [NewSp]
+ mov eax, dword [esp + 0x14]
+ mov edx, dword [esp + 0x10]
+ sub eax, edx
+ sub esp, eax
+ mov ebx, esp
+ push ecx
+ push eax
+ push edx
+ push ebx
+ call ASM_PFX(CopyMem)
+ pop eax
+ pop eax
+ pop eax
+ pop ecx
+
+ ; Now call the external routine
+ call ecx
+
+ ; ebp is preserved by the callee. In this function it
+ ; equals the original esp, so set them equal
+ mov esp, ebp
+
+ ; Standard function epilog
+ mov esp, ebp
+ pop ebx
+ pop ebp
+ ret
+
+;****************************************************************************
+; EbcLLEbcInterpret
+;
+; Begin executing an EBC image.
+;****************************************************************************
+; UINT64 EbcLLEbcInterpret(VOID)
+global ASM_PFX(EbcLLEbcInterpret)
+ASM_PFX(EbcLLEbcInterpret):
+ ;
+ ;; mov eax, 0xca112ebc
+ ;; mov eax, EbcEntryPoint
+ ;; mov ecx, EbcLLEbcInterpret
+ ;; jmp ecx
+ ;
+ ; Caller uses above instruction to jump here
+ ; The stack is below:
+ ; +-----------+
+ ; | RetAddr |
+ ; +-----------+
+ ; |EntryPoint | (EAX)
+ ; +-----------+
+ ; | Arg1 | <- EDI
+ ; +-----------+
+ ; | Arg2 |
+ ; +-----------+
+ ; | ... |
+ ; +-----------+
+ ; | Arg16 |
+ ; +-----------+
+ ; | EDI |
+ ; +-----------+
+ ; | ESI |
+ ; +-----------+
+ ; | EBP | <- EBP
+ ; +-----------+
+ ; | RetAddr | <- ESP is here
+ ; +-----------+
+ ; | Arg1 | <- ESI
+ ; +-----------+
+ ; | Arg2 |
+ ; +-----------+
+ ; | ... |
+ ; +-----------+
+ ; | Arg16 |
+ ; +-----------+
+ ;
+
+ ; Construct new stack
+ push ebp
+ mov ebp, esp
+ push esi
+ push edi
+ sub esp, 0x40
+ push eax
+ mov esi, ebp
+ add esi, 8
+ mov edi, esp
+ add edi, 4
+ mov ecx, 16
+ rep movsd
+
+ ; call C-code
+ call ASM_PFX(EbcInterpret)
+ add esp, 0x44
+ pop edi
+ pop esi
+ pop ebp
+ ret
+
+;****************************************************************************
+; EbcLLExecuteEbcImageEntryPoint
+;
+; Begin executing an EBC image.
+;****************************************************************************
+; UINT64 EbcLLExecuteEbcImageEntryPoint(VOID)
+global ASM_PFX(EbcLLExecuteEbcImageEntryPoint)
+ASM_PFX(EbcLLExecuteEbcImageEntryPoint):
+ ;
+ ;; mov eax, 0xca112ebc
+ ;; mov eax, EbcEntryPoint
+ ;; mov ecx, EbcLLExecuteEbcImageEntryPoint
+ ;; jmp ecx
+ ;
+ ; Caller uses above instruction to jump here
+ ; The stack is below:
+ ; +-----------+
+ ; | RetAddr |
+ ; +-----------+
+ ; |EntryPoint | (EAX)
+ ; +-----------+
+ ; |ImageHandle|
+ ; +-----------+
+ ; |SystemTable|
+ ; +-----------+
+ ; | RetAddr | <- ESP is here
+ ; +-----------+
+ ; |ImageHandle|
+ ; +-----------+
+ ; |SystemTable|
+ ; +-----------+
+ ;
+
+ ; Construct new stack
+ mov [esp - 0xC], eax
+ mov eax, [esp + 0x4]
+ mov [esp - 0x8], eax
+ mov eax, [esp + 0x8]
+ mov [esp - 0x4], eax
+
+ ; call C-code
+ sub esp, 0xC
+ call ASM_PFX(ExecuteEbcImageEntryPoint)
+ add esp, 0xC
+ ret
+
